colistin and Escherichia-coli-Infections

Multidrug-resistant (MDR) Escherichia coli strains have rapidly increased worldwide, and effective antibiotic therapeutic options are becoming more restricted. As a polymyxin antibiotic, colistin has a long history of usage, and it is used as a final line of treatment for severe infections by Gram-negative bacteria (GNB) with high-level resistance. However, its application has been challenged by the emergence of E. coli colistin resistance. Hence, determining the mechanism that confers colistin resistance is crucial for monitoring and controlling the dissemination of colistin-resistant E. coli strains. This comprehensive review summarizes colistin resistance mechanisms in E. coli strains and concentrates on the history, mode of action, and therapeutic implications of colistin. We have mainly focused on the fundamental mechanisms of colistin resistance that are mediated by chromosomal or plasmid elements and discussed major mutations in the two-component systems (TCSs) genes and plasmids that transmit the mobilized colistin resistance resistant genes in E. coli strains.

Topics: Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Microbial Sensitivity Tests; Plasmids

The continuing rise in infections caused by multidrug-resistant (MDR) bacteria is one of the most serious public-health issues in society today. Colistin is a last-resort antimicrobial drug used to treat infections caused by MDR Gram-negative bacteria, therefore resistance to this antibiotic is extremely hazardous. The current study aimed to evaluate the global prevalence nd distribution of colistin resistance genes among human clinical isolates of Escherichia coli by systematic review.. PubMed, Embase and Web of Science databases were systematically searched. For further evaluation, all original English language articles that reported colistin resistance in E. coli clinical isolates published between 2000 and 2020 were examined.. Of 4857 initial articles, after various stages of review and evaluation 190 related articles were selected for the systematic review. More than 79% of the publications selected in this research were published from 2014-2020. In Asia, Europe, America, Africa and Oceania, the prevalence of mobile colistin resistance (mcr)-harbouring colistin-resistant E. coli was 66.72%, 25.49%, 5.19%, 2.27% and 0.32 %, respectively.. The recent widespread dissemination of E. coli strains harbouring mcr genes conferring colistin resistance, especially in Asia and Europe, is concerning and requires more attention.

Topics: Colistin; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Molecular Epidemiology; Prevalence

Carbapenem-resistant Enterobacteriaceae infections have spread globally, leaving polymyxins, including colistin, as 'last-resort treatments'. Emerging colistin resistance raises the spectre of untreatable infections. Despite this threat, data remain limited for much of the world, including Southeast Asia where only 3 of 11 nations submitted data on carbapenem and colistin resistance for recent World Health Organization (WHO) reports. To improve our understanding of the challenge, we utilised broad strategies to search for and analyse data on carbapenem and colistin resistance among Escherichia coli and Klebsiella in Southeast Asia. We found 258 studies containing 526 unique reports and document carbapenem-resistant E. coli and Klebsiella in 8 and 9 of 11 nations, respectively. We estimated carbapenem resistance proportions through meta-analysis of extracted data for nations with ≥100 representative isolates. Estimated resistance among Klebsiella was high (>5%) in four nations (Indonesia, Philippines, Thailand and Vietnam), moderate (1-5%) in two nations (Malaysia and Singapore) and low (<1%) in two nations (Cambodia and Brunei). For E. coli, resistance was generally lower but was high in two of seven nations with ≥100 isolates (Indonesia and Myanmar). The most common carbapenemases were NDM metallo-β-lactamases and OXA β-lactamases. Despite sparse data, polymyxin resistance was documented in 8 of 11 nations, with mcr-1 being the predominant genotype. Widespread presence of carbapenem and polymyxin resistance, including their overlap in eight nations, represents a continuing risk and increases the threat of infections resistant to both classes. These findings, and remaining data gaps, highlight the urgent need for sufficiently-resourced robust antimicrobial resistance surveillance.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Asia, Southeastern; Carbapenem-Resistant Enterobacteriaceae; Carbapenems; Child; Child, Preschool; Colistin; Drug Resistance, Bacterial; Escherichia coli Infections; Female; Genotype; Humans; Infant; Infant, Newborn; Klebsiella Infections; Male; Middle Aged; Young Adult

Colistin has been re-assessed as a critically important antimicrobial in humans due to its efficacy against multi-drug resistant Gram-negative bacteria, in particular P. aeruginosa, A. baumannii, and K. pneumoniae. The recent discovery of mobile colistin resistance (mcr) determinants in humans and animals has brought concerns regarding the future of this antimicrobial. In this paper, we aim to highlight the current challenges with colistin resistant bacteria and to summarize reliable global data on colistin resistance in poultry production. In addition, we present and compare data from a screening for colistin resistance carried out on a collection of clinical Escherichia coli isolated from poultry in Italy. In Europe, resistance rates for Salmonella and E. coli are in general low with sporadic incidence of high colistin resistance levels. Absence of resistance or very low rates have been recorded in countries where colistin is either not employed (e.g. Norway) or used in minimal amounts (e.g. Denmark) in food-producing animals. In large poultry meat producing countries, such as China and Brazil, the widespread use of colistin has resulted in the dissemination of resistance determinants in diverse bacterial species. Worryingly, these bacteria are often co-resistant to other critically important antimicrobials, such as extended-spectrum cephalosporins. The data gap for many countries and for zoonotic bacteria, the role of the "phantom resistome" and the circulation of mcr-carriers expressing resistance phenotypes close or below the current ECOFF values, should be considered in future investigations. The importance of poultry as a cheap protein source and the global effort to mitigate colistin resistance and preserve this essential antimicrobial require a thorough re-assessment of colistin use in poultry.

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Italy; Poultry; Poultry Diseases; Poultry Products

Escherichia coli has become multiresistant by way of production of a variety of β-lactamases. The prevalence of CTX-M-producing E. coli has reached 60-79% in certain parts of Asia. The acquisition of CTX-M plasmids by E. coli sequence type 131, a successful clone of E. coli, has caused further dissemination of CTX-M-producing E. coli. The prevalence of carbapenemase-producing E. coli, especially Klebsiella pneumoniae carbapenemase, and New Delhi metallo-β-lactamase (NDM)-producing E. coli has been increasing in Asia. K. pneumoniae carbapenemase and NDM have now been found in E. coli sequence type 131. The occurrence of NDM-producing E. coli is a major concern particularly in the Indian subcontinent, but now elsewhere in Asia as well. There are multiple reasons why antibiotic resistance in E. coli in Asia has reached such extreme levels. Approaches beyond antibiotic therapy, such as prevention of antibiotic resistance by antibiotic stewardship and protecting natural microbiome, are strategies to avoid further spread of antibiotic resistance.

Topics: Anti-Bacterial Agents; Asia; beta-Lactamases; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Humans

Intravenous colistimethate sodium (CMS) is used to treat infections with multiresistant Gram-negative bacteria. Optimal dosing in patients undergoing continuous renal replacement therapy (CRRT) is unclear. In a prospective study, we determined CMS and colistin pharmacokinetics in 10 critically ill patients requiring CRRT (8 underwent continuous venovenous hemodialysis [CVVHD]; median blood flow, 100 ml/min). Intensive sampling was performed on treatment days 1, 3, and 5 after an intravenous CMS loading dose of 9 million international units (MU) (6 MU if body weight was <60 kg) with a consecutive 3-MU (respectively, 2 MU) maintenance dose at 8 h. CMS and colistin concentrations were determined by liquid chromatography with mass spectroscopy. A model-based population pharmacokinetic analysis incorporating CRRT settings was applied to the observations. Sequential model building indicated a monocompartmental distribution for both CMS and colistin, with interindividual variability in both volume and clearance. Hematocrit was shown to affect the efficacy of drug transfer across the filter. CRRT clearance accounted for, on average, 41% of total CMS and 28% of total colistin clearance, confirming enhanced elimination of colistin compared to normal renal function. Target colistin steady-state trough concentrations of at least 2.5 mg/liter were achieved in all patients receiving 3 MU at 8 h. In conclusion, a loading dose of 9 MU followed after 8 h by a maintenance dose of 3 MU every 8 h independent of body weight is expected to achieve therapeutic colistin concentrations in patients undergoing CVVHD using low blood flows. Colistin therapeutic drug monitoring might help to further ensure optimal dosing in individual patients. (This study has been registered at ClinicalTrials.gov under identifier NCT02081560.).

Topics: Adult; Aged; Anti-Bacterial Agents; Chromatography, Liquid; Colistin; Continuous Renal Replacement Therapy; Escherichia coli; Escherichia coli Infections; Female; Humans; Male; Mass Spectrometry; Middle Aged; Prospective Studies; Pseudomonas aeruginosa; Pseudomonas Infections

Colistin resistance associated with plasmidic resistance genes is a serious public health issue. We aimed at studying the transmission of an mcr-1 colistin- and rifampicin-resistant Escherichia coli strain between inoculated pigs and sentinels in different controlled conditions. Three groups of four pigs were bred in separated animal rooms and inoculated on Day 0 (D0). In each inoculated group, six contact pigs were introduced on D2. The first inoculated-and-contact group was left untreated. The ten pigs in the second inoculated-and-contact group received colistin (100 000 IU/kg) before inoculation or contact (D-7 to D-5), simulating prophylactic administration. Pigs in the third inoculated-and-contact group were treated just after inoculation or before transfer (D0 to D2), simulating metaphylactic administration. Faecal samples were regularly collected and segments of intestinal tracts were obtained at necropsy, on D20-D22. Samples were cultured on rifampicin-supplemented media, and PCR was used to detect the mcr-1 gene. The kinetics of infection, based on culture results, were analysed using an SIR model. The inoculated strain was detected in all inoculated and contact pigs. The SIR model showed that one infected pig could transmit the resistant bacteria to one susceptible individual in less than 3 h on average. Prophylactic administration significantly enhanced the transmission rate and resulted in more samples containing the mcr-1 resistance gene at necropsy. No effect of metaphylactic administration could be detected on the transmission rate, nor on the carriage of the resistant strain. Our study confirms that colistin should not be used in a prophylactic manner.

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Farms; Feces; Gene Transfer, Horizontal; Livestock; Microbial Sensitivity Tests; Plasmids; Polymerase Chain Reaction; Random Allocation; Rifampin; Swine

This study was conducted to determine the effects of the antimicrobial peptide cecropin on performance and intestinal health in piglets. Newly weaned barrows were randomly assigned to one of three treatments (n=8), including a corn-soybean basal diet or similar diets supplemented with antibiotics (100 mg/kg kitasamycin plus 800 mg/kg colistin sulfate) or 400 mg/kg cecropin AD. On day 13, all piglets were orally challenged with 10(9)CFU/mL of Escherichia coli K88. On day 19, all piglets were euthanized and sampled. Before challenge, piglets fed antibiotics had greater weight gain, feed efficiency, nitrogen and energy retention than the control (P<0.05). E. coli challenge decreased weight gain, feed intake and feed efficiency for the control piglets (P<0.05) but not for the antibiotic or cecropin AD treated piglets. The incidence of diarrhea post-challenge in the antibiotic and cecropin AD treatments decreased compared with the control piglets. The total viable counts of cecal E. coli were lower while the Lactobacilli counts were higher in the antibiotic and cecropin AD treatments compared with the control (P<0.05). Cecropin AD treatment decreased total aerobes while increasing total anaerobes in the ileum (P<0.05). A higher villus height to crypt depth ratio in the jejunum and ileum as well as a deeper crypt depth in the jejunum and higher villus height in the ileum were observed in piglets fed antibiotics or cecropin AD compared with control piglets (P<0.05). Piglets fed the control diet had lower levels of secretory IgA in their jejunum and lower serum IgA, IgG, interleukin-1β and interleukin-6 compared with the other treatments (P<0.05). Overall, these data suggest that cecropin AD enhances pig performance through increasing immune status and nitrogen and energy retention as well as reducing intestinal pathogens in weaned piglets.

Topics: Animals; Anti-Infective Agents; Colistin; Diarrhea; Eating; Escherichia coli; Escherichia coli Infections; Immunoglobulin A, Secretory; Immunoglobulin G; Insect Proteins; Interleukin-1beta; Interleukin-6; Intestines; Kitasamycin; Lactobacillus; Swine; Swine Diseases; Weight Gain

The objective of the study was to monitor the effect of two therapy regimens on experimental Escherichia coli mastitis. Single udder quarters of 12 cows that were at least 30 d postpartum were inoculated with 1500 cfu of E. coli. The inoculation was repeated in the contralateral quarter after a 3- to 4-wk interval. Initially, half of the cows were treated with antimicrobials, and the remaining half were left untreated. At the second inoculation, the cows that were originally treated were not treated, and vice versa. Therapy began 12 h after inoculation and consisted of parenteral trimethoprim-sulfadiazine (6 cows) or intramammary colistin sulfate (6 cows). Clinical signs, daily milk yield, bacterial count, and endotoxin content of the milk were recorded. Milk SCC, NAGase activity, and trypsin inhibitor capacity were also monitored. The response to bacterial challenge varied greatly among cows. Bacteria were eliminated from the quarters within 7 d in all but 1 cow. Treatment did not significantly affect the elimination rate of bacteria or any of the measured parameters. Significant positive correlations existed among milk bacterial counts, endotoxin concentrations, and clinical signs at the acute stage of the infection. Based on these findings, antimicrobial therapy of E. coli mastitis during lactation apparently is no more beneficial than no treatment.

Topics: Acetylglucosaminidase; Animals; Cattle; Colistin; Colony Count, Microbial; Endotoxins; Escherichia coli Infections; Female; Mastitis, Bovine; Milk; Pregnancy; Time Factors; Trimethoprim, Sulfamethoxazole Drug Combination; Trypsin Inhibitors

Topics: Adolescent; Adult; Aged; Ampicillin; Carbenicillin; Child; Child, Preschool; Clinical Trials as Topic; Colistin; Escherichia coli Infections; Female; Humans; Injections, Intravenous; Klebsiella Infections; Male; Middle Aged; Nalidixic Acid; Penicillins; Pseudomonas Infections; Sulfonamides; Tetracycline; Urinary Tract Infections; Urine

The emergence of mcr plasmid-mediated colistin-resistant extended-spectrum β-lactamase (ESBL)-producing Enterobacterales among companion dogs and cats poses a risk of the animals acting as reservoirs for cross-species transmission. However, current knowledge of mcr-harboring ESBL-producing Enterobacterales in companion dogs and cats is still limited; thus, the genetic and phenotypic characteristics of the bacterial isolates and plasmids, in companion dogs and cats, remain to be elucidated. Here, we identified mcr gene-harboring ESBL-producing Escherichia coli isolates during whole-genome sequencing of ESBL-producing E. coli isolates from a dog and a cat in Osaka, Japan. Colistin-resistant MY732 isolate from a dog carried two plasmids: mcr-1.1-harboring IncI2 plasmid and bla

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Cat Diseases; Cats; Colistin; Dog Diseases; Dogs; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Japan; Microbial Sensitivity Tests; Pets; Plasmids

Colistin resistance has been the subject of much attention since mcr genes encoding plasmid-mediated colistin resistance description in 2015. To date, surveillance data about resistance levels encountered in food-producing animals are scarce. In France, the Resapath dataset, consisting in a large collection of disk diffusion antibiogram results transmitted by a network of laboratories. It offers a unique opportunity to study the evolution of resistance towards colistin over the past 15 years in Escherichia coli isolated from diseased food-producing animals. This study used a Bayesian hierarchical Gaussian mixture model to estimate the resistant proportions from those data. This non-classical approach deals with the colistin-specific problem of overlapping distributions of diameters measured for susceptible and resistant isolates that makes the definition of epidemiological cut-off very hard. This model also considers the variability observed between the measurements performed by different laboratories. Proportion of resistant isolates has been calculated for several food-producing animals and most encountered diseases. From those estimations, a marked evolution of the proportions of resistant isolates is noticeable, for swine suffering from digestive disorders. In this group, an increase over the 2006-2011 period from 0.1% [ 0.0%, 1.2%] in 2006-28.6% [25.1%, 32.3%] in 2011 was followed by a decrease to reach 3.6% [2.3%;5.3%] in 2018. For isolates related to digestive disorders in calves, percentages increased and reached 7% in 2009 then decreased as for swine. In contrast, for poultry productions, estimated proportions and credibility intervals were constantly very close to zero.

Topics: Animals; Anti-Bacterial Agents; Bayes Theorem; Cattle; Cattle Diseases; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Microbial Sensitivity Tests; Plasmids; Poultry; Swine; Swine Diseases

Antimicrobial resistance encoded by mobile colistin resistance (

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Microbial Sensitivity Tests; Plasmids; Portugal; Swine

Foods of animal origin are increasingly considered a source of extended spectrum β-lactamase (ESBL) producing bacteria which can disseminate throughout the food chain and become a health concern for humans. This work aimed to evaluate the occurrence of ESBL-producing Escherichia coli in 100 retail minced meat samples taken in markets in Pamplona, Colombia. A total of 19 ESBL-producing isolates were obtained, 18 identified as E. coli and one as E. fergusonii. Fifteen isolates (78.9 %) carried bla

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Chickens; Colistin; Colombia; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Meat; Multilocus Sequence Typing; Phylogeny; Plasmids

Emergence and dissemination of resistance to last-resort antibiotics such as carbapenem and colistin is a growing, global health concern. Wastewater treatment plants (WWTPs) link human activities and the environment, can act as reservoirs and sources for emerging antibiotic resistance, and likely play a large role in antibiotic resistance transmission. The aim of this study was to investigate occurrence and characteristics of colistin- and carbapenem-resistant Escherichia coli (CCREC) in wastewater and sludge samples collected over a one-year period from different functional areas of an urban WWTP in Jinan city, Shandong, China. A total of 8 CCREC were isolated from 168 samples with selective agar and PCR, corresponding to high prevalence of 4.8%, co-harboring carbapenem resistance genes (bla

Topics: Anti-Bacterial Agents; beta-Lactamases; Carbapenems; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Microbial Sensitivity Tests; Plasmids; Prevalence

We monitored swine-derived Escherichia coli on a Japanese farm where colistin had been used for the treatment of diseases caused by bacteria and investigated colistin resistance and the presence of mcr-1 in 36 E. coli strains isolated before and after the withdrawal of colistin use. Through the withdrawal of colistin use on the farm, the prevalence of colistin-resistant and mcr-1-positive E. coli was markedly reduced but not eradicated because mcr-1 had been maintained in multiple plasmids and various sequence types of nonpathogenic E. coli carried in healthy swine. The monitoring of sequence types of mcr-1-positive E. coli is expected to be important for controlling colistin resistance in swine or other animals.

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Farms; Microbial Sensitivity Tests; Plasmids; Swine; Swine Diseases

Colistin is one of the last-resort antibiotics for treating infections caused by multidrug-resistant (MDR) Gram-negative bacteria. However,

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Genomics; Humans; Microbial Sensitivity Tests; Plasmids; Prevalence; Swine

MCR-positive Escherichia coli (MCRPEC) have been reported in humans worldwide. The high prevalence of mcr-1 poses clinical and environmental risks due to its diverse genetic mechanisms. Given the vital role of animals and the environment in the spread of antibiotic resistance, a "One Health" perspective should be taken when addressing antimicrobial resistance issues. This study conducted a prospective study in six farms (located in Jiaxing City, Zhejiang province, China) in 2019. MCRPEC strains were screened from samples of different sources. The molecular epidemiological surveys and transmission potential were investigated by whole-genome sequencing and phylogenetic analysis. MCRPEC were detected in different farms with various sources. Sequence type complex 10 was dominant and distributed widely in multiple sources. Core-genome multilocus sequence type (cgMLST) analysis indicated that clonal transmission could occur within and between farms. In addition, mcr-1 genes with different locations showed different transmission tendencies. The study indicated that interspecies and cross-regional transmission of MCRPEC could occur between different sectors in farms. Further surveillance and research of non-clinical MCRPEC strains are necessary to reduce the threat of MCRPEC.

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Genomics; Humans; Microbial Sensitivity Tests; Phylogeny; Plasmids; Prospective Studies

Treating multidrug-resistant infections has increasingly relied on last-resort antibiotics, including polymyxins, for example colistin. As polymyxins are given routinely, the prevalence of their resistance is on the rise and increases mortality rates of sepsis patients. The global dissemination of plasmid-borne colistin resistance, driven by the emergence of mcr-1, threatens to diminish the therapeutic utility of polymyxins from an already shrinking antibiotic arsenal. Restoring sensitivity to polymyxins using combination therapy with sensitizing drugs is a promising approach to reviving its clinical utility. Here we describe the ability of the biotin biosynthesis inhibitor, MAC13772, to synergize with colistin exclusively against colistin-resistant bacteria. MAC13772 indirectly disrupts fatty acid synthesis (FAS) and restores sensitivity to the last-resort antibiotic, colistin. Accordingly, we found that combinations of colistin and other FAS inhibitors, cerulenin, triclosan and Debio1452-NH

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli Infections; Fatty Acids; Mice; Polymyxins

One hundred fecal samples from hooded vultures in the Gambia (Banjul area) were investigated for the presence of bacteria with extended-spectrum cephalosporin- (ESBL/AmpC), carbapenemases, and colistin resistance. No Enterobacteriales carrying carbapenemases or resistance against colistin were detected. Fifty-four ESBL-producing Escherichia coli and five ESBL-producing Klebsiella pneumoniae isolates were identified in 52 of the samples, of which 52 E. coli and 4 K. pneumoniae yielded passed sequencing results. Fifty of the E. coli had ESBL phenotype and genotype harboring bla

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Birds; Colistin; Endangered Species; Escherichia coli; Escherichia coli Infections; Gambia; Humans; Klebsiella pneumoniae; Microbial Sensitivity Tests; Prevalence

Antimicrobial-resistant Escherichia coli strains have been circulating in various sectors and can be cross-transferred between them. Among pathogenic E. coli strains, Shiga toxin-producing E. coli (STEC) and hybrid pathogenic E. coli (HyPEC) emerged as responsible for outbreaks worldwide. As bovine are reservoir of STEC strains, these pathogens primarily spread to food products, exposing humans to risk. Therefore, this study aimed to characterize antimicrobial-resistant and potentially pathogenic E. coli strains from fecal samples of dairy cattle. In this regard, most E. coli strains (phylogenetic groups A, B1, B2, and E) were resistant to β-lactams and non-β-lactams and were classified as multidrug-resistant (MDR). Antimicrobial resistance genes (ARGs) related to multidrug resistance profiles were detected. Furthermore, mutations in fluoroquinolone and colistin resistance determinants were also identified, highlighting the deleterious mutation His152Gln in PmrB that may have contributed to the high level (> 64 mg/L) of colistin resistance. Virulence genes of diarrheagenic and extraintestinal pathogenic E. coli (ExPEC) pathotypes were shared among strains and even within the same strain, evidencing the presence of HyPEC (i.e., ExPEC/STEC), which were assigned as unusual B2-ST126-H3 and B1-ST3695-H31. These findings provide phenotypic and molecular data of MDR, ARGs-producing, and potentially pathogenic E. coli strains in dairy cattle, contributing to the monitoring of antimicrobial resistance and pathogens in healthy animals and alerting to potential bovine-associated zoonotic infections.

Topics: Animals; Anti-Infective Agents; Cattle; Cattle Diseases; Colistin; Escherichia coli Infections; Escherichia coli Proteins; Humans; Phylogeny; Shiga-Toxigenic Escherichia coli

Overuse of antibiotics and the emergence of multidrug-resistant bacteria has made colistin the last line of defence against complex infections. In previous studies, MCR-1-mediated colistin resistance was mainly detected through PCR or antimicrobial susceptibility testing. However, intuitive detection methods for phenotype are rarely reported. In this study, two small peptide antibodies were constructed for immunofluorescence detection of mcr-1-harbouring Escherichia coli: one was a small peptide labelled with a quantum dot antibody; and the other was a small peptide labelled with a fluorescein isothiocyanate (FITC) antibody. Whether using FITC or quantum dots, colistin-resistant bacteria in the sample could be qualitatively detected. The assembled antibodies achieved the desired goals in terms of sensitivity, specificity, precision and repeatability. The non-specific problem of sandwich antigen recognition of lipid A binding to small peptides in modified lipopolysaccharide (LPS) was resolved, and this relatively developed immunofluorescence technique standardised the detection process. Together, in addition to PCR, both fluorescent antibodies can be used for immunofluorescent detection of mcr-1-harbouring E. coli.

Topics: Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Fluorescein-5-isothiocyanate; Humans; Lipopolysaccharide Receptors; Microbial Sensitivity Tests; Plasmids; Quantum Dots

The transmission of potentially life-threatening plasmid-mediated antibiotic-resistant bacteria poses a major threat to public health. This study aimed to determine the presence of commonly observed plasmids encoding plasmid-mediated antibiotic-resistance genes in Salmonella and Escherichia coli isolates from fishery products. Eighty river fishes were purchased from retail stores and supermarkets in Vietnam. Only Salmonella-positive fishes were used for antibiotic-resistant E. coli isolation. Salmonella serotyping was performed using Salmonella antisera. Isolated bacterial DNA was extracted, and antibiotic susceptibility, resistance genes, and replicon typing were determined. Our results showed that Salmonella was isolated from 12.5% (10/80) of the river fishes. Cefotaxime-resistant Salmonella was isolated from 3.8% (3/80) of the fishes and colistin-resistant Salmonella from 1.3% (1/80) . Salmonella serotyping revealed Potsdam, Schwarzengrund, Bardo/Newport, Give, Infantis, Kentucky, and Typhimurium. Multiplex polymerase chain reaction revealed the presence of extended-spectrum β-lactamase-related genes bla

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Colistin; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Fishes; Plasmids; Salmonella; Salmonella enterica

Topics: Algeria; Anti-Bacterial Agents; beta-Lactamases; Colistin; Escherichia coli; Escherichia coli Infections; Humans; Prevalence

The United Arab Emirates (UAE) has witnessed rapid urbanization and a surge in pet ownership, sparking concerns about the possible transfer of antimicrobial resistance (AMR) from pets to humans and the environment. This study delves into the whole-genome sequencing analysis of ESBL-producing E. coli strains from healthy cats and dogs in the UAE, which exhibit multidrug resistance (MDR). Additionally, it provides a genomic exploration of the mobile colistin resistance gene mcr-1.1, marking the first instance of its detection in Middle Eastern pets.. We investigate 17 ESBL-producing E. coli strains from healthy UAE pets using WGS and bioinformatics analysis to identify genes encoding virulence factors, assign diverse typing schemes to the isolates, and scrutinize the presence of AMR genes. Furthermore, we characterized plasmid contigs housing the mcr-1.1 gene and conducted phylogenomic analysis to evaluate their relatedness to previously identified UAE isolates.. Our study unveiled a variety of virulence factor-encoding genes within the isolates, with fimH emerging as the most prevalent. Regarding β-lactamase resistance genes, the blaCTX group 1 gene family predominated, with CTX-M-15 found in 52.9% (9/17) of the isolates, followed by CTX-M-55 in 29.4% (5/17). These isolates were categorized into multiple sequence types (STs), with the epidemic ST131 being the most frequent. The presence of the mcr-1.1 gene, linked to colistin resistance, was confirmed in two isolates. These isolates belonged to ST1011 and displayed distinct profiles of β-lactamase resistance genes. Phylogenomic analysis revealed close connections between the isolates and those from chicken meat in the UAE.. Our study underscores the presence of MDR ESBL-producing E. coli in UAE pets. The identification of mcr-1.1-carrying isolates warrants the urgency of comprehensive AMR surveillance and highlights the role of companion animals in AMR epidemiology. These findings underscore the significance of adopting a One Health approach to mitigate AMR transmission risks effectively.

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Cats; Chickens; Colistin; Dogs; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Genomics; Humans; Meat; One Health; Plasmids; United Arab Emirates

Antibiotic persistence is a phenomenon observed when genetically susceptible cells survive long-term exposure to antibiotics. These 'persisters' are an intrinsic component of bacterial populations and stem from phenotypic heterogeneity. Persistence to antibiotics is a concern for public health globally, as it increases treatment duration and can contribute to treatment failure. Furthermore, there is a growing array of evidence that persistence is a 'stepping-stone' for the development of genetic antimicrobial resistance. Urinary tract infections (UTIs) are a major contributor to antibiotic consumption worldwide, and are known to be both persistent (i.e. affecting the host for a prolonged period) and recurring. Currently, in clinical settings, routine laboratory screening of pathogenic isolates does not determine the presence or the frequency of persister cells. Furthermore, the majority of research undertaken on antibiotic persistence has been done on lab-adapted bacterial strains. In the study presented here, we characterized antibiotic persisters in a panel of clinical uropathogenic

Topics: Anti-Bacterial Agents; Bacteria; Colistin; Escherichia coli Infections; Humans; Meropenem; Urinary Tract Infections; Uropathogenic Escherichia coli

Antimicrobial resistance is a worldwide problem after the emergence of colistin resistance since it was the last option left to treat carbapenemase-resistant bacterial infections. The mcr gene and its variants are one of the causes for colistin resistance. Besides mcr genes, some other intrinsic genes are also involved in colistin resistance but still need to be explored.. The aim of this study was to investigate differential proteins expression of colistin-resistant E. coli clinical isolate and to understand their interactive partners as future drug targets.. In this study, we have employed the whole proteome analysis through LC-MS/MS. The advance proteomics tools were used to find differentially expressed proteins in the colistin-resistant Escherichia coli clinical isolate compared to susceptible isolate. Gene ontology and STRING were used for functional annotation and protein-protein interaction networks, respectively.. LC-MS/MS analysis showed overexpression of 47 proteins and underexpression of 74 proteins in colistin-resistant E. coli. These proteins belong to DNA replication, transcription and translational process; defense and stress related proteins; proteins of phosphoenol pyruvate phosphotransferase system (PTS) and sugar metabolism. Functional annotation and protein-protein interaction showed translational and cellular metabolic process, sugar metabolism and metabolite interconversion.. We conclude that these protein targets and their pathways might be used to develop novel therapeutics against colistin-resistant infections. These proteins could unveil the mechanism of colistin resistance.

Topics: Anti-Bacterial Agents; Chromatography, Liquid; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Microbial Sensitivity Tests; Plasmids; Proteomics; Sugars; Tandem Mass Spectrometry

Colistin is considered a last-resort antibiotic against carbapenem-resistant isolates. Currently, this antibiotic is facing the emergence of mobilised colistin resistance (mcr) genes, which confer colistin resistance. This study conducted genomic characterisation of an atypical multidrug-resistant Escherichia coli harbouring two mcr genes in France. Samples collected from a pig farm in Avignon (Vaucluse department) were subjected to molecular screening targeting mcr variants.. Samples were cultured on selective Lucie-Bardet-Jean-Marc-Rolain medium. Growing bacteria were identified using MALDI-TOF, followed by antibiotic susceptibility testing. Whole-genome sequencing and bioinformatic genome analysis were performed.. Selective culture of stools revealed the presence of an E. coli strain named Q4552 harbouring mcr-1.1 and mcr-3.5 genes, which is also resistant to 14 antibiotics. Genome sequencing and assembly yielded a complete and circular chromosome and eight different plasmids. Sequence analysis demonstrated an integration of a mobile genetic element carrying mcr-1.1 in the chromosome, whereas mcr-3.5 was in the plasmid and its resistome was composed of 22 resistance genes. The Q4552 strain was identified as an ST-843 clone that belonged to the clonal complex Cplx-568 and is the only ST type of this cplx-568 that has been isolated from animals, humans, and the environment.. We report the first co-occurrence of mcr-1 and mcr-3 genes in France from a pathogenic E. coli isolated from a pig. Because this clone (ST-843) has been reported in zoonotic transmissions, programs to monitor the bacterium are urgently required to avoid its spread and zoonotic transmission to humans.

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Genomics; Swine

To investigate the occurrence and molecular features of ESBL-producing and colistin-resistant Escherichia coli isolates recovered from healthy food-producing animals in Pakistan.. A total of 153 E. coli isolates were recovered from 250 faecal samples collected from livestock and poultry. The antibiotic susceptibility, resistant determinants and mobile genetic elements were determined for all the isolates. The clonal relatedness was analysed by MLST. Plasmids harbouring, localization and transferability of mcr-1 gene were carried out by Southern hybridization, S1-PFGE and transconjugation.. Out of 153 E. coli strains, 49.01% isolates were ESBLs producers, whereas 18.95% were resistant to colistin and 84.31% of the isolates. Multidrug resistance was found in 84% of the isolates. The ESBL-producing E. coli in buffaloes, cattle, sheep, goat and broilers faecal samples were 60%, 74%, 54%, 50% and 68%, respectively. Among the ESBLs genes, bla. The co-occurrence of mcr-1 and ESBLs-encoding genes, along with MGEs in E. coli from healthy food animals in Pakistan, is a major concern.. Antimicrobial resistance can be transferred from animals to humans by direct contact or via the food chain and environment. The prevalence and co-occurrence of ESBL and colistin resistance genes from food-producing animals is rare in Pakistan. To our knowledge, this is the first report to find ESBLs and mcr-1-harbouring E. coli from the faecal samples of the healthy food-producing animals in Pakistan. The presence of ARGs in association with MGEs, co-harbouring the virulence factors, as determined in the current study, is a severe threat to livestock and the human community as it has horizontally and food web transferability.

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Cattle; Chickens; Colistin; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Incidence; Multilocus Sequence Typing; Pakistan; Plasmids; Sheep

Colistin is frequently used for the control of post-weaning diarrhoea in pigs. Colistin resistance caused by plasmidic genes is a public health issue. We evaluated, in experimental animal facilities, whether free colistin or colistin-loaded on alginate nanoparticles (colistin/Alg NPs) could select a colistin-resistant Enterotoxigenic Escherichia coli. The Alg NPs were produced by a simple top-down approach through ball milling of sodium alginate polymer precursor, and colistin loading was achieved through physical adsorption. Colistin loading on Alg NPs was confirmed using various tools such Fourier transform infrared spectroscopy and dynamic light scattering measurements. Thirty-four piglets were orally inoculated or not with a mcr-1-positive, rifampicin-resistant enterotoxigenic E. coli strain, and the inoculated pigs were either treated or not during five days with commercial colistin (100,000 IU/kg) or colistin/Alg NPs (40,415 IU/kg). Clinical signs were recorded. Fecal and post-mortem samples were analyzed by culture. The result clearly indicated that colistin/Alg NPs had a slightly better therapeutic effect. Both treatments led to a transitory decrease of the total E. coli fecal population with a majority of colistin-resistant E. coli isolates during treatment, but the dominant E. coli population was found susceptible at the end of the trial. Further studies are needed to evaluate, in diverse experimental or field conditions, the therapeutic efficacy of colistin/Alg NPs for post-weaning diarrhoea.

Topics: Alginates; Animals; Anti-Bacterial Agents; Colistin; Enterotoxigenic Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Nanoparticles; Swine

This study aimed to determine the percentage of colistin resistant and ESBL-producing Escherichia coli from clinically sick and healthy pigs and understand the molecular mechanisms underlying colistin resistance and ESBL production. A total of 454 E. coli isolates from healthy pigs (n = 354; piglets, n = 83; fattening pigs, n = 142 and sows, n = 100) and sick pigs (n = 100) were examined for antimicrobial susceptibility, chromosomal and plasmid-mediated colistin resistance mechanisms and ESBL genes. The healthy (41%) and sick pig (73%) isolates were commonly resistant to colistin. Three mcr genes including mcr-1 (10.4%), mcr-2 (1.1%) and mcr-3 (45%) were detected, of which mcr-3 was most frequently detected in the healthy (33%) and sick pig (57%) isolates. Coexistence of mcr-1/mcr-3 and mcr-2/mcr-3 was observed in piglets (23%), fattening pig (3.5%) and sick pig (13%) isolates. Three amino acid substitutions including E106A and G144S in PmrA and V161G in PmrB were observed only in colistin-resistant isolates carrying mcr-3. The percentage of ESBL-producing E. coli was significantly higher in the sick pigs (44%) than the healthy pigs (19.2%) (P = 0.00). The bla

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Farms; Feces; Female; Genes, Bacterial; Genotype; Male; Microbial Sensitivity Tests; Phenotype; Plasmids; Swine; Swine Diseases

Since the gene encoding mobilised colistin resistance (mcr-1) was first reported in China in 2015, it has been reported in various Enterobacteriaceae worldwide. Escherichia coli, one of the main pathogens causing diarrhoea, is the most prevalent, clinically identified species carrying mcr-1. This study aimed to investigate the epidemiologic and genomic characteristics of mcr-1 in Escherichia coli from patients in Shanghai.. Faecal samples were collected from hospitals in Shanghai between 2012 and 2015. Polymerase chain reaction was performed to detect mcr-1, and molecular characteristics of the mcr-1-positive E. coli was determined by antimicrobial susceptibility testing and whole-genome sequencing.. We detected 40 (3.9%) mcr-1-positive E. coli strains from faecal samples in clinical settings between 2012 and 2015 in Shanghai. Mcr-1 was detected in 4 types of E. coli, including atypical enteropathogenic E. coli (aEPEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), and enteroaggregative E. coli (EAEC). Most strains harbouring mcr-1 were isolated from children aged <7 years. Whole-genome sequencing revealed that nearly half of the strains that carried quinolone resistance- or β-lactam resistance-related genes were multidrug-resistant. IncX4 was the predominant type in mcr-1-positive E. coli in Shanghai, but the other types of mcr-1-harbouring plasmids are highly diverse in genetic context.. These data suggest that mcr-1 is prevalent in E. coli strains, especially those identified in diarrhoeal patients in Shanghai, and strengthening the surveillance of mcr-1 transmission, especially in children, is essential.

Topics: Anti-Bacterial Agents; Child; China; Colistin; Diarrhea; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Microbial Sensitivity Tests

Emergence of pathogens harboring multiple resistance genes incurs great concerns. Cooccurrence of mobile resistance genes conferring resistance to tigecycline, colistin, and carbapenems in Escherichia coli has not been investigated. This study aimed to characterize three E. coli isolates coharboring

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Microbial Sensitivity Tests; Plasmids; Tigecycline

This study investigated the prevalence and characteristics of mcr-1-harbouring Escherichia coli isolated from chickens in central China from 2014 to 2019.. A total of 1132 E. coli isolated from 1647 chicken swabs were analysed for colistin susceptibility by broth microdilution method and prevalence of mcr-1 gene by PCR. The colistin-resistant E. coli isolates were typed by multi-locus sequence typing (MLST) and tested with 12 antimicrobial agents. The transconjugation assay was conducted for the mcr-1-positive isolates using the transconjugant E. coli C600.. Of the 1132 E. coli isolated from chickens, 131 isolates (11.6%) exhibited colistin resistance, and 51 isolates (4.5%) were mcr-1 positive. The mcr-1-positive rate was quite low in 2014 (2.3%) and 2015 (1.7%), increased to peak in 2016 (12.6%) and 2017 (11.4%), and then decreased significantly in 2018 (1.7%) and 2019 (0.9%). The 131 colistin resistant isolates were assigned to 66 unique sequence types (STs), 27 of which contained mcr-1-positive isolates. Compared with mcr-1-negative E. coli, mcr-1-positive E. coli showed higher resistance rates to nalidixic acid, ciprofloxacin, ceftriaxone, cefotaxime, and tetracycline. Furthermore, 30 of the 51 mcr-1 positive isolates transduced their mcr-1 gene into E. coli C600, and 13 of the 30 transconjugants carried more than one replicon types.. The mcr-1 positive rate varied enormously during 2014-2019 in central China. The ban on colistin likely decreased the dissemination of mcr-1 in E. coli isolates from chickens. Multidrug-resistant trait is observed in mcr-1 positive E. coli isolates and can be transferred into other transconjugants.

Topics: Animals; Chickens; Colistin; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Microbial Sensitivity Tests; Multilocus Sequence Typing; Prevalence

Prevalence of widespread bacterial infections brings forth a critical need to understand the molecular mechanisms of the antibiotics as well as the bacterial response to those antibiotics. Improper use of antibiotics, which can be in sub-lethal concentrations is one among the multiple reasons for acquiring antibiotic resistance which makes it vital to understand the bacterial response towards sub-lethal concentrations of antibiotics. In this work, we have used colistin, a well-known membrane active antibiotic used to treat severe bacterial infections and explored the impact of its sub-minimum inhibitory concentration (MIC) on the lipid membrane dynamics and morphological changes of

Topics: Anti-Bacterial Agents; Bacteria; Colistin; Escherichia coli; Escherichia coli Infections; Humans; Microbial Sensitivity Tests

Antimicrobial resistance is a quintessential One Health issue, among the most serious 21st century global threats in human and veterinary medicine. Wild animals are usually not directly exposed to clinically relevant antibiotics; however, antibacterial resistance in wild animals has been increasingly reported worldwide in parallel to the situation in human and veterinary medicine. In this work, we collected 100 fecal samples from the crested ibis protected areas. A total of eight Escherichia coli (E. coli) isolates positive for mcr-1 were obtained, and all of them were analyzed using WGS (whole genome sequencing). The WGS analysis showed that the isolates were assigned to four different sequence types (ST) overall. The antibiotic susceptibility profile showed that of eight E. coli isolates, six strains exhibited resistance to tetracycline and all mcr-1-positive E. coli (MCREC) strains showed resistance to colistin. Our findings importantly document the epidemic spread of MCREC in crested ibis in China.

Topics: Animals; Anti-Bacterial Agents; Birds; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Microbial Sensitivity Tests; Plasmids

Plasmid-mediated colistin resistance genes, especially mcr-3 combined with the fosfomycin resistance gene fosA3, are a grave health concern. Our study was designed to determine the epidemiological characteristics of the combination of mcr-3 and fosA3 in Anhui province, China.. A total of 127 multi-drug-resistant (MDR) E. coli strains were assessed for antibiotic resistance/sensitivity to detect mcr-3 and fosA3 using polymerase chain reaction (PCR) and sequencing. The genes of interest were conjugated using EC600, and replicon and sequence types (STs) were identified by PCR-based replicon typing (PBRT) and multilocus sequence typing (MLST). Cluster similarity and genomic relatedness among the positive isolates were confirmed by Xbal PFGE.. The processed E. coli isolates were highly resistant to the tested antibiotics; the prevalence of mcr-3 was 0.78% in the transferable IncP-type plasmid in ST131, whereas fosA3 prevalence was 38.58% among different transferable plasmids, including IncFIIK, IncFII and IncA/C, and in various STs including ST69, ST1193, ST12, ST46, ST57, ST1196, ST38, ST95, ST131, ST7584 and ST10184. Both were successfully transferred to EC600. The Xbal PFGE cluster exposed similarities among the STs.. Our results show that to control the spread of colistin and fosfomycin resistance genes in human pathogens, the ban on colistin must be continued in animal feeding farms not only in China but around the world; additionally, awareness platforms on the use of colistin must be implemented and strict policies in poultry and pig farms must be maintained. Furthermore, fosfomycin misuse by patients and overuse by physicians must be strictly managed to stop the spread of fosfomycin resistance.

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Colistin; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Fosfomycin; Humans; Microbial Sensitivity Tests; Multilocus Sequence Typing; Plasmids; Swine

We describe an innovative use for the recently reported fast lipid analysis technique (FLAT) that allows for the generation of MALDI tandem mass spectrometry data suitable for lipid A structure analysis directly from a single Gram-negative bacterial colony. We refer to this tandem MS version of FLAT as FLAT

Topics: Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Lipid A; Microbial Sensitivity Tests

Colistin is one of the last-resort antibiotics for infections caused by multidrug-resistant Gram-negative bacteria. However, the wide spread of novel plasmid-carrying colistin resistance genes

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Microbial Sensitivity Tests; Plasmids; RNA; RNA, Messenger

In the Netherlands, antimicrobial resistance (AMR) is monitored in commensal indicator Escherichia coli from healthy broilers at slaughter as part of a European monitoring programme. In a separate programme for poultry health, AMR is monitored in veterinary pathogens from diseased broilers. So far, it is unknown how the outcomes of these two AMR monitoring approaches in the same animal population are associated.. This study aims to investigate the association between the outcomes of monitoring non-wildtype susceptibility (using epidemiological cut-off values, ECOFF, as prescribed by EU legislation) in commensal E. coli isolated from healthy broilers (i.e. active surveillance) with the outcomes of monitoring clinical resistance (using clinical breakpoints, to determine susceptibility for antibiotic treatment in veterinary practice) in E. coli isolated from diseased broilers (i.e. passive surveillance).. Data acquired by broth microdilution was analysed for commensal indicator E. coli and clinical E. coli from the Netherlands, 2014-2019. A generalized linear multivariable model (Poisson regression) was used to determine time trends and identify differences in mean resistant proportions.. Observed resistant proportions of the monitored commensal E. coli and clinical E. coli were similar with overlapping confidence intervals for most time points for ampicillin, gentamicin, cefotaxime, tetracycline, colistin and trimethoprim/sulfonamide. The statistical analysis showed that only for cefotaxime and tetracycline, mean resistant proportions were different. In commensal E. coli, a decrease of resistant proportions over time was observed, except for gentamicin. In clinical E. coli, no time trend was detected in resistant proportions, except for cefotaxime and colistin.. Generally, the resistant proportions monitored in commensal and clinical E. coli were similar. However, some relevant differences were found, which can be explained by the type of monitoring approach, i.e. active or passive surveillance. The random sample of commensal E. coli isolated from healthy animals (active surveillance), was more suitable to monitor AMR time trends. The sample of clinical isolates from diseased animals (passive surveillance), resulted in a higher chance to detect low-prevalent resistance: i.e. cefotaxime and colistin. The clinical E. coli data showed more fluctuation over time, and data from a longer period of time would be needed to determine the association. This study shows the value of both an active and a passive surveillance component for AMR monitoring.

Topics: Animals; Anti-Bacterial Agents; Cefotaxime; Chickens; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Gentamicins; Microbial Sensitivity Tests; Tetracyclines

Topics: Animals; Anti-Bacterial Agents; Colistin; Columbidae; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Microbial Sensitivity Tests; Plasmids

Antibiotic-resistant Escherichia coli is one of the most serious problems in pig production. This study aimed to determine the antibiotic susceptibility and genotypes profiles of diarrhoeagenic E. coli that causes diarrhea in piglets. Thirty-seven pathogenic E. coli strains were used in this study. These were isolated from rectal swabs of diarrheic piglets from farms in Thailand from 2018 to 2019. Escherichia coli isolates were highly resistant to amoxicillin (100%), followed by oxytetracycline (91.9%), enrofloxacin (89.2%), trimethoprim/sulfamethoxazole (86.5%), amoxicillin: clavulanic acid (81.1%), colistin and gentamicin (75.7%), ceftriaxone and ceftiofur (64.9%), ceftazidime (35.1%) and 97.3% showed multidrug-resistance (MDR). There were 8 (21.6%) mcr-1 carriers, 10 (27.0%) mcr-3 carriers and 10 (27.0%) co-occurrent mcr-1 and mcr-3 isolates. The phenotype-genotype correlation of colistin resistance was statistically significant (performed using Cohen's kappa coefficient (κ = 0.853; p < 0.001)). In addition, PCR results determined that 28 of 37 (75.7%) isolates carried the int1 gene, and 85.7% int1-positive isolates also carried the mcr gene. Genetic profiling of E. coli isolates performed by ERIC-PCR showed diverse genetics, differentiated into thirteen groups with 65% similarity. Knowledge of the molecular origins of multidrug-resistant E. coli should be helpful for when attempting to utilize antibiotics in the pig industry. In terms of public health awareness, the possibility of transmitting antibiotic-resistant E. coli from diarrheic piglets to other bacteria in pigs and humans should be of concern.

Topics: Amoxicillin; Animals; Anti-Bacterial Agents; Colistin; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Farms; Swine; Thailand

The widespread dissemination of phenotypic colistin-resistant (COR) bacteria in the community threatens public health. The horizontal gene transfer of the mobile colistin resistance gene via plasmids is thought to be one of the main mechanisms for dissemination. However, genotypic evidence to prove this in community settings is limited. This study used genome analysis to demonstrate the direct horizontal colistin resistance gene transfer via plasmids in isolates from the community.. A total of 19 isolates of COR Escherichia coli from stool specimens of 23 residents from seven households in the Vietnamese community were assessed in this study. The whole-genome sequence data of isolates were acquired using a combination of DNBSEQ short-reads and Nanopore long-read sequencing. Analysis of genomic data was performed using online tools such as Geneious. Analysis of the genomic information of COR E. coli isolates revealed that the isolates from two residents of different households had a similar IncP1 plasmid possessing mcr-1.1, marked with a single nucleotide mutation at the same position. The study provided direct evidence to prove that mcr was horizontally transmitted among bacteria in community residents.

Topics: Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Microbial Sensitivity Tests; Mutation; Nucleotides; Plasmids

The extensive spread of colistin resistance represents an enormous concern to infectious disease treatment, because colistin is one of the few effective antibiotics against multidrug-resistant bacterial infections, including carbapenem-resistant bacteria. This dissemination can be caused by plasmid transfer containing the colistin resistance gene mcr. Therefore, the plasmid host range affects horizontal gene transfer. This study reports a fusion plasmid of different incompatibility types, which could easily expand the plasmid host range, allowing widespread mcr prevalence in the microbial community.. Genome sequences of colistin-resistant Escherichia coli isolates from stool specimens of healthy human residents in Ecuador were determined using the DNBSEQ and MinION platforms. Hybrid genome assembly was performed using Unicycler, and the genomes were annotated using DFAST. Genome analysis was performed using the Geneious Prime software.. Two colistin-resistant E. coli strains isolated separately from different residents presented mcr-carrying plasmids with fused different incompatibility types, IncFIA, IncHIIA, and IncHIIB. The phylogenies of these host bacteria were different. The sizes of the mcr-carrying fusion plasmids pLR-06 and pLR-50 with the full Tn6330 mcr-transposon were 260 Kbp and 198 Kbp, respectively. Both fusion plasmids possessed other resistance genes, including tet(B), tet(M), bla. This is the first report of a fusion plasmid comprising different incompatibility types with mcr from colistin-resistant E. coli strains isolated from community residents. The mcr fusion plasmid may play a crucial role in achieving horizontal mcr transmission and the evolution of the multidrug resistance plasmid among hosts.

Topics: Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Plasmids

The expansion of mcr-carrying bacteria is a well-recognized public health problem. Measures to contain mcr spread have mainly been focused on the food-animal production sector. Nevertheless, the spread of MCR producers at the environmental interface particularly driven by the increasing population of gulls in coastal cities has been less explored. Occurrence of mcr-carrying Escherichia coli in gull's colonies faeces on a Portuguese beach was screened over 7 months. Cultural, molecular and genomic approaches were used to characterize their diversity, mcr plasmids and adaptive features. Multidrug-resistant mcr-1-carrying E. coli were detected for 3 consecutive months. Over time, multiple strains were recovered, including zoonotic-related pathogenic E. coli clones (e.g. B2-ST131-H22, A-ST10 and B1-ST162). Diverse mcr-1 genetic environments were mainly associated with ST2/ST4-HI2 (ST10, ST131, ST162, ST354 and ST4204) but also IncI2 (ST12990) plasmids or in the chromosome (ST656). Whole-genome sequencing revealed enrichment of these strains on antibiotic resistance, virulence and metal tolerance genes. Our results underscore gulls as important spreaders of high-priority bacteria and genes that may affect the environment, food-animals and/or humans, potentially undermining One-Health strategies to reduce colistin resistance.

Topics: Animals; Anti-Bacterial Agents; Charadriiformes; Clone Cells; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Interleukin-1 Receptor-Like 1 Protein; Livestock; Microbial Sensitivity Tests; Plasmids

Escherichia coli O157 belongs to a diverse serogroup including different H serotypes. E. coli O157: H7 is the most common serotype that can cause acute gastroenteritis, hemorrhagic colitis (HC), and hemolytic-uremic syndrome (HUS) in humans. In recent years, some E. coli O157:non-H7 strains have been reported to cause sporadic cases and outbreaks of diarrheal diseases. However, the phenotypic and genotypic characteristics of E. coli O157:non-H7 are poorly understood. In this study, E. coli O157:non-H7 strains were isolated from retail food sold on markets in 13 cities in China during 2012-2016 and characterized systematically in terms of their H serotypes, virulence genes, antibiotic resistance, and genotypes. Six H serotypes (H26, H42, H11, H38, H4, and H5) were identified, of which, O157:H42 (31.4 %) and O157:H26 (28.6 %) were the most prevalent. Most of the isolates (82.9 %) carried virulence genes. Ten isolates (28.6 %) carried the eae gene and were identified as atypical enteropathogenic E. coli. Multilocus sequence typing showed that the E. coli O157:non-H7 strains demonstrated diverse sequence types with different evolutionary trends than E. coli O157:H7. All the isolates exhibited multidrug resistance. The isolates showed a high prevalence of resistance to AMC, AMP, CTX, CIP, T/S, TE, and FFC. The predominant antibiotic-resistance genes were TEM-1 (40.0 %), CTX-M-55 (34.3 %), aadA (74.3 %), sul2 (62.9 %), floR (91.4 %), tetA (85.7 %), qnrS (37.1 %), oqxA (62.9 %), and oqxB (62.9 %). For the first time, we identified IncI2 plasmid-mediated colistin-resistant strains (six O157:H26 and one O157:H4). These strains co-harbored plasmid-mediated mcr-1 gene, CTX-M-55, OXA-4, PMQR, and other resistant genes, which is of great concern. Colistin and cefotaxime are generally used as the last defense to treat complicated infections. The emergence of virulent and multidrug resistant strains in food poses a serious threat to human health. The strict monitoring and surveillance of multiple-drug resistant strains in food are needed to prevent their dissemination to humans.

Topics: Colistin; Enteropathogenic Escherichia coli; Escherichia coli Infections; Escherichia coli O157; Escherichia coli Proteins; Humans

Antimicrobial resistant Escherichia coli have become an ever increasing problem in human, and animal health and production. The imprudent use of antibiotics and poor hygienic practices especially in poultry industries have been contributing to the emergence and spread of E. coli species resistant to broad spectrum antibiotics including Colistin. This study was conducted to detect colistin - resistance and antibiotic sensitivity patterns in E. coli isolated from broiler chickens in Kelantan. A total of 320 cloacal swabs were collected from apparently healthy broiler chickens in different districts of Kelantan and were analysed using routine microbiological methods, Kirby-Bauer method for antimicrobial susceptibility test and PCR amplification of species-specific and colistin - resistance encoding genes. Out of the 320 samples, 91 isolates were confirmed as E. coli and 21/91 (23.08%) were positive for colistin - resistant encoding gene, mcr-1. Most of the isolates were resistant to tetracycline (95.24%), chloramphenicol (85.71%), and sulphamethoxazole/ trimethoprim (85.71%). However, the isolates were less resistant towards piperacillin/ tazobactam (4.76%) and meropenem (9.52%). The findings from this study reveal the emerging threats of colistin - resistant in local food animal production, particularly in poultry production industry. However, more comprehensive, and large-scale studies focusing on more resistance patterns using determination of minimum inhibitory concentration (MIC), virulence and resistance characteristics and molecular epidemiology of colistin - resistant E. coli are recommended for better understanding of the epidemiology and to implement the appropriate control and prevention strategies.

Topics: Animals; Anti-Bacterial Agents; Bird Diseases; Chickens; Colistin; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Malaysia; Microbial Sensitivity Tests

Plasmid-Mediated Colistin Resistance 1 (mcr-1) was first reported in 2015 and is a great concern to human health. In this study, we investigated the prevalence of mcr-1 and mcr-1-positive Escherichia coli (MCRPEC) and the association in infection status among various reservoirs connected to livestock. The study was conducted in 70 poultry and swine farms in a commune in Ha Nam province, northern Vietnam. Samples were collected from farmers, food animals, domestic animals, and farm environments (flies and wastewater) for polymerase chain reaction (PCR) screening for mcr-1 gene and species identification of PCR positive isolates. Among 379 obtained mcr-1 positives isolates, Escherichia coli was the major identified, varying from 50% (2/4) in dog feces to 100% (31/31) in humans feces isolates. The prevalence of MCRPEC was 14.4% (20/139), 49.7% (96/193), 31.3% (25/80), 36.7% (40/109), 26.9% (18/67), and 3.9% (2/51) in humans, chickens, pigs, flies, wastewater, and dogs, respectively. The study identified association between MCRPEC infection status in humans and flies (OR = 3.4), between flies and chickens (OR = 5.3), and between flies and pigs (OR = 9.0). Farmers' age and farm livestock unit were also associated factors of MCRPEC infection status in humans (OR = 5.1 and 1.05, respectively). These findings bring new knowledge on antibiotic resistance in livestock setting and important suggestions on potential role of flies in the transmission of mcr-1 resistance gene.

Topics: Animals; Anti-Bacterial Agents; Chickens; Colistin; Dogs; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Farms; Humans; Livestock; Microbial Sensitivity Tests; Plasmids; Swine; Vietnam; Wastewater

As an opportunistic pathogen,

Topics: Animals; Anti-Bacterial Agents; Biflavonoids; Biofilms; Carrier Proteins; Colistin; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans

The aim of this study was to characterize three strains of colistin-resistant E. coli isolated from feces samples of healthy individuals in Thailand. The three strains, namely, SY_EC03, SY_EC07, and SY_EC10 were identified as ST165, ST1602, and ST34. All isolates exhibited multidrug-resistant phenotype, which is mediated by accumulation of various antimicrobial resistance genes. SY_EC03 contained mcr-1.1 while SY_EC07 co-harbored mcr-2.3 and mcr-3.4, and SY_EC10 co-harbored mcr-1.1 and mcr-3.5. Genomic analysis revealed that mcr-1.1 of the two strains were located on IncI2 plasmid with genetic environment of ISApl1-mcr-1.1-PAP2, which is a composite transposon Tn6330 with single-ended. Regarding mcr-2.3, the gene was identified within the composite transposon of ISKpn71-mcr-2.3-ISSpu2-ISKpn71, which was located on a novel mobile genetic element (MGE) that was integrated into the chromosome by phage integrase. For mcr-3.4 and mcr-3.5, the genes were confirmed to locate on the chromosome by S1-PFGE/DNA hybridization. Hence, to the best of our knowledge, this is the first report on co-occurrence of mcr-2 and mcr-3 on chromosome of E. coli. More interestingly, mcr-2 was found to locate on a novel MGE, which had never been described. In addition, we also report the co-occurrence of plasmidic mcr-1.1 and chromosomal mcr-3.5 which is extremely rare. Since all these bacteria were isolated from healthy individuals and the identified STs have been found in a variety of origins, all these clones may serve as reservoir for horizontal and vertical transmission of mcr genes. Strategic action plans to control and prevent the spread of mcr genes are urgently needed.

Topics: Anti-Bacterial Agents; Chromosomes; Colistin; DNA; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Integrases; Microbial Sensitivity Tests; Plasmids; Thailand

The emergence of multidrug-resistant (MDR) bacteria harboring tet(X4), bla

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Birds; China; Colistin; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Metagenomics; Microbial Sensitivity Tests; Molecular Epidemiology; Plasmids

The threat of antimicrobial resistance is increasing. Microbial food contamination poses a serious public health risk; however, there are only a few studies on the prevalence of colistin-resistant Escherichia coli (COL-E) contamination in freshwater fish. This study aimed to characterise the antibiotic resistance genes and antibiotic susceptibility profiles of COL-E in freshwater fish in Vietnam. In total, 103 fish were collected and 63 COL-E were isolated. COL-E was investigated by genotyping mcr and AmpC/extended-spectrum β-lactamase (ESBL)-related genes. The results show that COL-E and AmpC/ESBL-producing COL-E were confirmed in 24.3 % and 14.6 % of the fish, respectively. Multiplex PCR for mcr-1-9 showed that all 63 COL-E harboured mcr-1, while mcr-3 was detected in 7.9 % of COL-E. The minimum inhibitory concentration of colistin ranged from 2 to 256 μg/mL. Meanwhile, antibiotic susceptibility results show that all COL-E were resistant to ampicillin, streptomycin, and chloramphenicol.

Topics: Ampicillin; Animals; Anti-Bacterial Agents; beta-Lactamases; Chloramphenicol; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Fresh Water; Microbial Sensitivity Tests; Plasmids; Streptomycin

Thailand is undergoing rapid intensification of livestock production where small subsistence farms and medium sized commercial farms coexist. In medium farms, antimicrobials are prescribed by a veterinarian, whereas in small farms antimicrobial use remains largely unsupervised. The impact of these differences as well as other farming practices on the emergence and composition of antimicrobial resistance genes (ARGs) remains largely unknown. We analyzed 363 genomes of extended-spectrum ß-lactamase producing (ESBL) and/or AmpC producing Escherichia coli recovered from humans and pigs at small and medium farms from the Khon Kaen province, Thailand. We tested for genome-wide associations to identify links between ARGs, host, and farm size. Pig isolates from small farms were associated with mcr and qnr genes conferring resistance to colistin and fluoroquinolones, respectively. In contrast, pig isolates from medium farms were associated with ARGs conferring resistance to drugs commonly used on medium farms (i.e., streptomycin). ESBL plasmids from small farms co-carried ARGs conferring resistance to critically important antimicrobials more frequently compared to plasmid from medium farms. Frequent ARG combinations included bla

Topics: Animals; Anti-Bacterial Agents; Anti-Infective Agents; beta-Lactamases; Colistin; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Farms; Fluoroquinolones; Humans; Plasmids; Streptomycin; Swine; Thailand

Escherichia coli ST1485 strains belong to the clinically important phylogroup F and have disseminated worldwide in humans, animals, and the environment. Here, we elucidated the pathogenome of a global collection of E. coli ST1485 isolates from diverse sources retrieved from public databases and a high-quality sequenced complete genome of colistin-resistant E. coli strain CFSAN061771 isolated from raw milk cheese which designated as a reference strain. CFSAN061771 belongs to O83:H42-ST1485 pathotype and carries a conjugative ColV plasmid, pCFSAN061771_01, combining extraintestinal virulence genes (ompt, sitA, iroN, etsC, traT, cvaC, hylF, iss, tsh, mchf, iucC, iutA) with a multidrug resistance island (bla

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Phylogeny; Plasmids

Antimicrobial-resistant (AMR) pathogens are a significant threat to public health worldwide. However, the primary carrier of AMR genes, particularly against last-resort antibiotics, is still only partially studied in Chinese hospitals. In a sentinel hospital in China, we collected 157

Topics: Animals; beta-Lactamases; Carbapenems; Colistin; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Hospitals; Microbial Sensitivity Tests; Plasmids

Extended spectrum beta-lactamase (ESBL) producing. This study investigated the faecal carriage of ESBL producing and colistin resistant. Twenty-one of the included. The avian ESBL producing

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Chickens; Colistin; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Phylogeny; Poultry; Zimbabwe

Our objective was to characterize the genetic features of plasmids harbored by two genetically related, MCR-1 and NDM-5-producing Escherichia coli strains recovered from a chicken meat sample. The genetic profiles of all plasmids harbored by the two test strains, namely, 1106 and 1107, were determined by whole-genome sequencing, S1-pulsed-field gel electrophoresis (PFGE), Southern hybridization, and bioinformatics analysis. The transferability of plasmids harbored by the two strains was assessed by filter mating assay. Strains 1106 and 1107 were resistant to almost all the antibiotics, including colistin and fosfomycin, but remained susceptible to amikacin and tigecycline. The plasmids of p1107-NDM-5 and p1106-NDM-5 both contain a class I integron which lacks the IS

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Carbapenems; Chickens; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Foodborne Diseases; Gene Transfer, Horizontal; Genome, Bacterial; Humans; Meat; Microbial Sensitivity Tests; Plasmids; Whole Genome Sequencing

The increased and inappropriate use of colistin led to the emergence of its resistance among Gram-negative bacterial isolates and the most common mechanism of colistin resistance in Gram-negative bacteria is the modification of the lipopolysaccharide mediated by two-component regulatory systems, PhoPQ and PmrAB. The aim of the present study was to investigate the transcriptional expression of the PhoPQ system against colistin stress in clinical isolates of Escherichia coli with colistin-resistant phenotype. Six colistin-resistant E. coli isolates were obtained from Silchar Medical College and Hospital, Silchar that were of clinical origin and received for routine culture and sensitivity testing. Screening for colistin resistance was done by broth microdilution method and further screened for the presence of the different types of plasmid-mediated colistin resistance mcr genes namely, mcr-1 to mcr-10 by polymerase chain reaction (PCR). The screened positive isolates were subjected to PCR assay targeting phoP and phoQ genes and their expression was measured by quantitative real-time PCR. The results of this study revealed that two E. coli isolates (TS2 and TS4) were found to carry the mcr-1 gene. PhoP and PhoQ gene amplification was observed in all the isolates. Transcriptional analysis showed that the isolates harboring the mcr-1 gene showed an enhanced level of expression in the PhoP, PhoQ genes in the presence of a subinhibitory concentration of colistin whereas no significant expression was observed for the isolates which were devoid of the mcr gene. This study demonstrates the involvement of mcr-1 in the PhoPQ system in clinical isolates of colistin-resistant E. coli which will help in designing a molecular marker for detecting colistin-resistant E. coli and contribute to the assessment of resistance burden and infection control strategy.

Topics: Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Gene Expression Regulation, Bacterial; Humans; Microbial Sensitivity Tests; Plasmids; Stress, Physiological; Transcription, Genetic

The environment is considered a major reservoir of antimicrobial resistant microorganisms (AMR) and antimicrobial resistance genes (ARG). Colistin, a "last resort" antibiotic, is used for the treatment of severe infections caused by multidrug-resistant Gram-negative bacteria. The global dissemination of mobile colistin resistance genes (mcr) in natural and non-natural environments is a major setback in the fight against antimicrobial resistance. Hitherto, there is a limited number of studies screening this resistance determinant in bacteria from wildlife. In this study, we describe for the first time the detection of plasmid-mediated colistin resistance in Escherichia coli from wild ungulates in Portugal, which are also widely distributed across Europe. This information is critical to identify the importance of ungulates in the dissemination of resistant bacteria, and their corresponding genes, across the environment. Here, 151 resistant-Enterobacteriaceae isolated from 181 samples collected from different wild ungulate species throughout Portugal were screened for mcr genes. Four mcr-1-positive Escherichia coli were detected from four fallow deer individuals that were sampled in the same hunting ground. These four isolates harboured mcr-1-related IncP plasmids belonging to sequencing types ST155, ST533 and ST345 (n = 2), suggesting bacterial and/or plasmid circulation. All mcr-1-positive E. coli also showed other resistance phenotypes, including MDR, including the B1 commensal phylogenetic profile. All mcr-1-positive E. coli show additional resistance phenotypes, including MDR, including the B1 commensal phylogenetic profile. Our findings are upsetting, highlighting the global dissemination of colistin resistance genes in the whole ecosystem, which, under the One Health framework, emphasizes the urgent need for effective implementation of AMR surveillance and control in the human-animal-environment interfaces.

Topics: Animals; Anti-Bacterial Agents; Colistin; Deer; Drug Resistance, Bacterial; Ecosystem; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Microbial Sensitivity Tests; Phylogeny; Plasmids

Knowledge on the dynamic of MDR Escherichia coli in the human community is still limited, especially in low- and middle-income countries. Our goal was to decipher the dynamics of E. coli lineages and plasmids resistant to ESC, carbapenem and colistin within and between food workers in Lebanon using genomic-based approaches.. Eighty-four healthy adults working in three bakeries were sampled twice at a 6 monthly interval. E. coli resistant to ESC (ESC-E), carbapenem (CP-E) and colistin (CO-E) were collected on selective plates. Non-duplicate isolates were whole-genome sequenced using the Illumina technology and plasmid transmission was assessed by long-read sequencing. Data were analysed using bioinformatics tools and SNP-based phylogeny.. ESC-E carriage rate reached 34.5% (t0) and 52.9% (t6), and 15 workers were positive at both t0 and t6. Carbapenem resistance (blaOXA-181, blaOXA-204, blaNDM-5) was found in five workers at t0 and two at t6, while colistin resistance (mcr-1.1) was found in five workers at t0 and one at t6. Forty-seven different STs were identified, of which three STs were predominant (ST131, n = 9; ST10, n = 5; ST69, n = 5). One worker presented the same ESC-E clone at t0 and t6. Twelve different events of clonal transmission among individuals were exemplified while plasmid transmission was only shown once.. Our study revealed a high carriage rate of MDR E. coli (60.7%) and the emergence of CP and colistin resistance in the Lebanese community. Incidental and long-term ESC-E carriage was observed in 41.7% and 17.9% of the workers, respectively. The high clonal diversity suggests an important dynamic of acquisition and loss of MDR E. coli and limited plasmid spread.

Topics: Adult; Anti-Bacterial Agents; Carbapenems; Clone Cells; Colistin; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Lebanon; Microbial Sensitivity Tests; Plasmids

This study was conducted to explore the prevalence and transmission of mcr-1 Escherichia coli among healthy rural residents in Shandong, China, and to provide theoretical basis for the prevention and control of spread and treatment of multi-drug resistant Escherichia coli. A total of 218 healthy residents from 3 villages in Guan County, Shandong Province, China were included in this study, and their fecal samples were collected. Colistin-resistant Escherichia coli were selected, and their drug sensitivity and plasmids' transferability were measured. After analysis, some conclusions can be drawn. The colistin-resistant Escherichia coli, most strains of which are MDROs, is common and highly transmissible in healthy residents in rural areas in China. Interventions should be implemented to prevent the spread of colistin-resistant Escherichia coli through health education and tighter regulation of antibiotics.

Topics: China; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Prevalence

The emergence of the plasmid-mediated colistin resistance gene

Topics: Anti-Bacterial Agents; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Genes, Bacterial; Humans; Microbial Sensitivity Tests; Plasmids; Tigecycline

Topics: Colistin; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans

Colistin provides in vitro activity against numerous ESBL-producing and carbapenem-resistant bacteria. However, clinical information with respect to its utilization in infection caused by ESBL producers is limited. The aim of this study was a comparison of mortality rates of loading dose (LD) colistin and carbapenems as definitive therapies in a cohort of patients with infections caused by ESBL-producing Escherichia coli and Klebsiella pneumoniae. A retrospective cohort study in 396 patients with ESBL-producing E.coli and K.pneumoniae infection at a university-affiliated hospital was conducted between 1 January 2005 and 30 June 2015 to compare outcomes of infected patients who received LD colistin (95 patients) with carbapenems (301 patients). The three primary outcomes were 30-day mortality, clinical response and microbiological response. The most common infection types were urinary tract infection (49.49%), followed by pneumonia (40.66%), bacteremia (13.64%), skin and soft tissue infections (4.80%) and intra-abdominal infection (3.03%). LD colistin group provided higher 30-day mortality when compared with carbapenems group (HR 7.97; 95% CI 3.68 to 17.25; P = 0.001). LD colistin was also independently associated with clinical failure (HR 4.30; 95% CI 1.93 to 9.57; P = 0.001) and bacteriological failure (HR 9.49; 95% CI 3.76 to 23.96; P = 0.001) when compared with those who received carbapenems. LD colistin treatment was associated with poorer outcomes, i.e. mortality rate, clinical response and microbiological response. Moreover, when adjusted confounding factors, LD colistin was still less effective than carbapenems. It should be noted that, however, the use of Vitek-2 to assess colistin susceptibility could provide inaccurate results. Also, the difference in baseline characteristics could still remain in retrospective study although compensation by hazard ratio adjustment was performed. Therefore, clinical utilization of LD colistin should be recommended as an alternative for treatment ESBL-producing Enterobacteriaceae only in the circumstances where carbapenems cannot be utilized, but this recommendation must be considered carefully.

Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; beta-Lactamases; Carbapenems; Cohort Studies; Colistin; Escherichia coli; Escherichia coli Infections; Female; Humans; Kaplan-Meier Estimate; Klebsiella Infections; Klebsiella pneumoniae; Male; Middle Aged; Retrospective Studies; Treatment Outcome

Escherichia coli (E. coli) is an indicator of antimicrobial resistance, and some strains of E. coli cause infectious diseases. E. coli sequence type 131 (ST131) - a global antimicrobial-resistant pandemic E. coli clone - is frequently detected in clinical specimens. Antimicrobial-resistant bacteria are monitored via national surveillance in clinical settings; however, monitoring information in non-clinical settings is limited. This study elucidated antimicrobial resistance trends of E. coli and dissemination of ST131 among healthy people in non-clinical settings.. This study collected 517 E. coli isolates from healthy people in Osaka, Japan, between 2013 and 2019. It analysed antimicrobial susceptibility of the isolates and detected the bla and mcr genes in ampicillin-resistant and colistin-resistant isolates, respectively, and the ST131 clone.. Antimicrobial resistance rates of the bacteria isolated from healthy people in non-clinical settings were lower than for those in clinical settings. The resistance of the isolates to cefotaxime (4.4%) and ciprofloxacin (13.5%) gradually increased during the study period. In 23 cefotaxime-resistant isolates, the most frequent bla genes belonged to the bla. Both ciprofloxacin resistance and O25b-ST131 clone frequency increased during the study period. Antimicrobial-resistant bacteria gradually spread in healthy people in non-clinical settings; one reason behind this spread was dissemination of global antimicrobial-resistant pandemic clones.

Topics: Ampicillin; Anti-Bacterial Agents; beta-Lactamases; Carrier State; Cefotaxime; Ciprofloxacin; Colistin; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Epidemiological Monitoring; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Feces; Humans; Japan; Microbial Sensitivity Tests; Polymerase Chain Reaction; Prevalence

The emergence of colistin-resistant Enterobacteriaceae from human and animal sources is one of the major public health concerns as colistin is the last-resort antibiotic for treating infections caused by multidrug-resistant Gram-negative bacteria. We aimed to determine the prevalence of the prototype widespread colistin resistance genes (mcr-1 and mcr-2) among commensal and pathogenic Escherichia coli strains isolated from food-producing and companion animals in Iran.. A total of 607 E. coli isolates which were previously collected from different animal sources between 2008 and 2016 used to uncover the possible presence of plasmid-mediated colistin resistance genes (mcr-1 and mcr-2) by PCR. Overall, our results could not confirm the presence of any mcr-1 or mcr-2 positive E. coli among the studied isolates. It is concluded that despite the important role of food-producing animals in transferring the antibiotic resistance, they were not the main source for carriage of mcr-1 and mcr-2 in Iran until 2016. This study suggests that the other mcr variants (mcr-3 to mcr-9) might be responsible for conferring colistin resistance in animal isolates in Iran. The possible linkage between pig farming industry and high level of mcr carriage in some countries needs to be clarified in future prospective studies.

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Iran; Microbial Sensitivity Tests; Plasmids; Prospective Studies; Swine

The plasmid-mediated

Topics: Animals; Anti-Bacterial Agents; Chickens; Colistin; Drug Resistance, Bacterial; Egypt; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Fosfomycin; Plasmids; Tigecycline

Colistin resistance mediated by plasmids for their rapid dissemination in Enterobacteriaceae is alarming. We aimed to characterize the genetic features of mcr-1 gene as well as the role of promoters in gene expression and levels of colistin resistance among clinical isolates of Enterobacteriaceae.. Clinical isolates of Enterobacteriaceae were collected in thirteen cities in China and screened for mcr-1 gene using polymerase chain reaction (PCR) amplification and sequencing. Antimicrobial susceptibility testing, transformation assay and plasmid sequencing, quantitative real-time PCR were performed for mcr-1-positive isolates. Promoter-probe vector pKK232-8 was utilized to assess the activity of the mcr-1 promoters.. This study identified the mcr-1 gene in 15 clinical isolates of Enterobacteriaceae, among which 14 were resistant to colistin, with MICs of 4-8 mg/L, while one mcr-1-bearing isolate EC09 was susceptible to colistin, with an MIC of 0.5 mg/L. Moreover, mcr-1-harbouring plasmids from 10 clinical isolates were transferrable via transformation and belonged to different incompatibility groups (IncI2 and IncX4). Plasmid pEC09 failed to transform and belonged to IncP1. A genetic structure containing the mcr-1-pap2 element was detected in these plasmids. EC09 demonstrated the lowest transcription level of mcr-1 gene, as determined by quantitative real-time PCR, which was in accordance with its susceptibility to colistin. Furthermore, the promoter activity of mcr-1 in pEC09 was the lowest, as determined by promoter-probe vector pKK232-8.. Promoter variations were associated with expression of the mcr-1 gene and ultimately the levels of colistin resistance.

Topics: Anti-Bacterial Agents; China; Colistin; Drug Resistance, Bacterial; Drug Resistance, Multiple, Bacterial; Enterobacteriaceae; Escherichia coli Infections; Escherichia coli Proteins; Humans

A plasmid-mediated mechanism of bacterial resistance to polymyxin is a serious threat to public health worldwide. The present study aimed to determine the occurrence of plasmid-mediated colistin resistance genes and to conduct the molecular characterization of mcr-positive Escherichia coli strains isolated from Polish poultry.. In this study, 318 E. coli strains were characterized by the prevalence of mcr1-mcr5 genes, antimicrobial susceptibility testing by minimal inhibitory concentration method, the presence of antimicrobial resistance genes was screened by PCR, and the biofilm formation ability was tested using the crystal violet staining method. Genetic relatedness of mcr-1-positive E. coli strains was evaluated by multilocus sequence typing method.. Among the 318 E. coli isolates, 17 (5.35%) harbored the mcr-1 gene. High antimicrobial resistance rates were observed for ampicillin (100%), tetracycline (88.24%), and chloramphenicol (82.35%). All mcr-1-positive E. coli strains were multidrug-resistant, and as many as 88.24% of the isolates contained the bla. Our results showed a low occurrence of mcr-1-positive E. coli strains isolated from Polish poultry; however, all the isolated strains were resistant to multiple antimicrobial agents and were able to form biofilms at low or medium level.

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Microbial Sensitivity Tests; Plasmids; Poland; Poultry; Tetracycline

Topics: Anti-Bacterial Agents; Chlorhexidine; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Microbial Sensitivity Tests

Colistin resistance due to the

Topics: Anti-Bacterial Agents; Bacterial Proteins; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Humans; Microbial Sensitivity Tests; Mutation, Missense; Phylogeny; Taiwan

Topics: Animals; Anti-Bacterial Agents; Carbapenems; Chickens; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Microbial Sensitivity Tests; Plasmids; Poultry Diseases

This study investigated the existence of sulfonamides and colistin resistance genes among extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli recovered from fish gut in Vietnam and evaluated the susceptibility patterns of the ESBL-producing E. coli to relevant antimicrobials. A total of 88 ESBL-producing E. coli isolates were analysed for the presence of the ESBLs, sul (1, 2, 3) and mcr (1-3) genes by PCR. Antimicrobial resistance phenotypes of isolates were determined by disc diffusion. Results showed that: (i) A high prevalence of 94·3% of sulfonamide resistance was observed in 88 isolates. Moreover, the existence of 2·3% of ESBL-producing E. coli harbouring mcr-1 gene were detected; (ii) The phylogenetic types A and B1 were most frequent, and the bla

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Colistin; Disk Diffusion Antimicrobial Tests; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Fishes; Gastrointestinal Microbiome; Phylogeny; Seafood; Sulfonamides; Vietnam

To characterize the colistin-resistant bacterial population in the gut and assess diversity of mcr-1 transmission within a single individual.. Large numbers of isolates (>100 colonies/chicken cecum sample) were collected from nine randomly selected mcr-1-positive chickens in China and used for comprehensive microbiological, molecular and comparative genomics analyses.. Of 1273 colonies, 968 were mcr-1 positive (962 Escherichia coli, two Escherichia fergusonii, two Klebsiella pneumoniae and two Klebsiella quasipneumoniae). One to six colistin-resistant species and three to 10 E. coli pulsed-field gel electrophoresis (PFGE) clusters could be identified from each sample. Whole-genome sequencing (WGS) analysis of the representative E. coli strains revealed three to nine sequence types observed in a single chicken host. The mcr-1 genes are located in either chromosomes or plasmids of different types, including IncI2 (n=30), IncHI2 (n=14), IncX4 (n=4), p0111(n=2) and IncHI1(n=1). Strikingly, in single cecum samples, one to five Inc type plasmids harbouring mcr-1 could be identified. Great diversity was also observed for the same IncI2 plasmid within a single chicken host. In addition, up to eight genetic contexts of the mcr-1 gene occurred within a single chicken.. There is extensive heterogeneity and flexibility of mcr-1 transmission in chicken gut due to bacterial species differences, distant clonal relatedness of isolates, many types and variations of mcr-positive plasmids, and the flexible genetic context of the mcr-1 gene. These compelling findings indicate that the gut is a 'melting pot' for active horizontal transfer of the mcr-1 gene.

Topics: Animals; Anti-Bacterial Agents; Cecum; Chickens; China; Colistin; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Enterobacteriaceae; Enterobacteriaceae Infections; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Gene Transfer, Horizontal; Microbial Sensitivity Tests; Plasmids; Poultry Diseases; Whole Genome Sequencing

Limited therapeutic options exist for treating severe infections caused by multidrug-resistant (MDR) and extensively drug-resistant Gram-negative bacteria (GNB). In this study, the activity of colistin (COL) as monotherapy and in combination with other antibiotics against Acinetobacter baumannii in vitro was investigated. In addition, the efficacy of intravenous colistimethate sodium (CMS) was evaluated in a murine model of urinary tract infection (UTI) induced by MDR Escherichia coli.. Minimum inhibitory concentration (MIC), Monte Carlo simulation, fractional inhibitory concentration index (FICI), time-kill study and erythrocyte lysis assay were applied to evaluate the effect and cytotoxicity of COL, meropenem, imipenem, doripenem (DOR) and sulbactam alone and in combination. For the in vivo experiment, determination of the bacterial burden and histopathological examination were performed to evaluate the efficacy of CMS against UTI.. Of 106 A. baumannii isolates, 104 (98.1%) were susceptible to COL. In the chequerboard assay, COL + DOR showed the highest rate of synergism (60%). No antagonism or cytotoxicity was observed. All COL-based combinations were able to inhibit or slow bacterial re-growth in a time-kill assay. In an in vivo activity study, intravenous CMS reduced not only the bacterial load but also inflammation and maintained structural integrity of infected bladders and kidneys.. The effectiveness of COL alone in vitro and in vivo suggested that intravenous CMS will be an effective and available therapeutic strategy for UTI due to MDR-GNB. In-depth in vitro tests demonstrated that COL + DOR could be an attractive option, especially when the COL MIC is ≥1 μg/mL.

Topics: Acinetobacter baumannii; Administration, Intravenous; Animals; Anti-Bacterial Agents; Biofilms; Colistin; Disease Models, Animal; Doripenem; Drug Resistance, Multiple, Bacterial; Drug Synergism; Drug Therapy, Combination; Escherichia coli; Escherichia coli Infections; Female; Humans; Imipenem; Meropenem; Mice; Microbial Sensitivity Tests; Monte Carlo Method; Sulbactam; Treatment Outcome; Urinary Tract Infections

We performed a survey aimed at analyzing milk samples collected from cows with mastitis for the presence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli. Single-quarter mastitic milk samples obtained from 400 cows in 23 Greek dairy herds with a history of E. coli mastitis were processed for the selective isolation of ESBL-producing E. coli. The antimicrobial susceptibility of the ESBL-producing isolates was analyzed using agar disk diffusion, and minimum inhibitory concentrations of colistin were determined by broth microdilution. We used PCR followed by DNA sequencing to characterize the β-lactamases and mcr-1 (colistin resistance) genes, and for phylotyping and multilocus sequence typing. We found a total of 89/400 (22.25%) E. coli isolates from 12/23 (52%) farms. Six isolates originating from 6 cows on a single farm were ESBL producers and were resistant to cefquinome, amoxicillin-clavulanic acid, aztreonam, ampicillin, and colistin. Five of these isolates were resistant to trimethoprim-sulfamethoxazole, and 5 to streptomycin. The 6 ESBL producers were mcr-1-positive and carried bla

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Cattle; Cephalosporins; Colistin; Dairying; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Farms; Female; Greece; Mastitis, Bovine; Microbial Sensitivity Tests; Milk; Multilocus Sequence Typing

The recurrence of multi-drug resistant (MDR) pathogens to the latest antibiotics and the limited development of new antibacterial agents have reduced the options for the treatment of severe infections. The reintroduction of old antibiotics, such as colistin, represents an effective strategy, since the latest antibiotics are over-consumed and ineffective against MDR pathogens. In 2015, Liu (Lancet Infect Dis 16:161-168, 2016) reported Escherichia coli (E. coli) isolates carrying plasmid-mediated colistin resistance gene mcr-1. The first of mcr-1 positive colistin-resistant (col-R) E. coli from a human blood culture was observed in 2012 in Latin America, while in Italy was reported for the first time by our center in 2016. The present study aimed to describe the prevalence of mcr-1 positive col-R strains in E. coli-related bloodstream infection among patients hospitalized in Fondazione IRCCS Policlinico San Matteo in Pavia, Italy, from 2012 to 2018, including the three cases already published.. All col-R E. coli strains isolated from blood cultures collected during the study period were analyzed. The minimal inhibitory concentration of colistin was determined using broth microdilution and detection of mcr-1 and mcr-2 genes was performed by PCR. The sequence type of E. coli mcr-1 positive was determined according to Multilocus sequence typing.. Out of 1557 samples, 14 strains (0.90%) were col-R. and positive for the presence of the mcr-1 gene, with no mcr-2 detected. The most common ST was ST10 (n = 3), followed by ST410 (n = 2). The remaining strains exhibited different MLST profiles, indicating that they were genetically unrelated.. Proper reporting of the presence of mcr-1 genes is an essential component to anticipate the spread of colistin resistance. This public health issue is particularly alarming in Italy due to the consistent circulation of MDR bacteria.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Child, Preschool; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Female; Hematologic Diseases; Hospitalization; Humans; Italy; Male; Middle Aged; Retrospective Studies; Young Adult

Topics: Aged; beta-Lactamases; Colistin; Computational Biology; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Greece; High-Throughput Nucleotide Sequencing; Humans; Multilocus Sequence Typing; Whole Genome Sequencing

Organic acids (OA) and phytogenic compounds have been used in pig feeding as alternatives to antibiotic growth promoters. However, few studies have evaluated the systemic effect of the combination of these additives. The aim of this study was to assess the impact of an organic acid-based feed additive (OAFA), containing a blend of OA and cinnamaldehyde, on the tissue integrity of bacterially challenged piglets. Thirty weaned piglets 21 d old were used in a 19-d trial. Pigs received a standard diet during the first 7 d and afterward were allotted to five treatments. Dietary treatments were: Control (basal diet), Escherichia coli (basal diet and challenge with E. coli), colistin (basal diet + 200 mg colistin/kg feed + challenge with E. coli), OAFA1 (basal diet + 1 kg OAFA/ton feed + challenge with E. coli), and OAFA2 (basal diet + 2 kg OAFA/ton feed + challenge with E. coli). Seven days after the beginning of the treatment, the animals were challenged with an enterotoxic strain of E. coli (K88) for pigs. Five days after the challenge, all animals were euthanized for tissue sampling for histological and oxidative stress (intestine and liver) analysis. The reduced glutathione (GSH), ferric-reducing ability potential (FRAP), and free-radical scavenging ability (ABTS) assays were used to evaluate the intestinal antioxidant defense. Lipid peroxidation and superoxide anion production were evaluated through the levels of thiobarbituric acid-reactive substances (TBARS) and nitroblue tetrazolium (NBT) reduction assay, respectively. Animals fed the OAFA (1 and 2) diets had a decrease (P < 0.05) on histological changes in the intestine, liver, mesenteric lymph nodes, and spleen. Greater villus height (VH) and a higher ratio of VH to crypt depth (CD) were observed in animals of the OAFA2 group compared with the control and E. coli groups. The colistin and OAFA groups decreased (P < 0.05) the number of inflammatory cells in intestinal lamina propria. OAFA2 group increased (P < 0.05) intestinal cell proliferation. Colistin and OAFA2 supplementation induced a decrease (P < 0.05) in the levels of TBARS in both the intestine and liver compared with the E. coli group. In addition, an increase (P < 0.05) in GSH and FRAP ileal levels was observed in the OAFA2 group compared with E. coli group. These results show that the supplementation with OAFA in the diet of weaned piglets, especially at a dose of 2 kg/ton (OAFA2) protected tissues against enterotoxigenic Escherichia coli (

Topics: Acrolein; Animals; Anti-Bacterial Agents; Carboxylic Acids; Colistin; Diet; Eating; Enterotoxigenic Escherichia coli; Escherichia coli Infections; Female; Homeostasis; Intestinal Mucosa; Intestines; Liver; Male; Oxidative Stress; Swine; Weaning

An

Topics: Animals; Anti-Bacterial Agents; China; Colistin; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Feces; Interspersed Repetitive Sequences; Microbial Sensitivity Tests; Plasmids; Swine; Transferases (Other Substituted Phosphate Groups)

Infections by multidrug-resistant Gram-negative bacteria are increasingly common, prompting the renewed interest in the use of colistin. Colistin specifically targets Gram-negative bacteria by interacting with the anionic lipid A moieties of lipopolysaccharides, leading to membrane destabilization and cell death. Here, we aimed to uncover the mechanisms of colistin resistance in nine colistin-resistant

Topics: Anti-Bacterial Agents; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Microbial Sensitivity Tests; Mutation; Phylogeny; Signal Transduction; Tertiary Care Centers; Whole Genome Sequencing

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Feces; Mass Screening; Microbial Sensitivity Tests; Real-Time Polymerase Chain Reaction; Swine; Swine Diseases

Colistin is used as one of the last-resort drugs against lethal infections caused by carbapenem-resistant pathogens of the Enterobacteriaceae family. Enterobacteriaceae bacteria carrying the mcr-1 colistin resistance gene are emerging in livestock and poultry, posing a serious threat to human health. However, there have been few reports about the prevalence and transmission of mcr-1 along the regional chicken supply chain. In this study, the complete sequences of mcr-1-positive Escherichia coli ST2705 and ST206 isolates obtained by screening 129 chilled chicken samples and 251 chicken fecal samples were investigated. Both of these isolates showed resistance to colistin, and importantly, the complete sequence of the mcr-1-positive E. coli ST2705 in China was reported for the first time. The mcr-1 gene was located on the IncHI2 plasmids pTBMCR421 (254,365 bp) and pTBMCR401 (230,964 bp) in strains ECCNB20-2 and ECZP248, respectively. Comparative analysis of mcr-1-bearing IncHI2 plasmids showed a marked similarity, indicating that these plasmids are very common and have the ability to be efficient vehicles for mcr-1 dissemination among humans, animals, and food. Furthermore, an insertion (ISKpn26) in Tn6330 (ISApl1-mcr-1-pap2-ISApl1) was identified in the plasmid pTBMCR401 and then compared; this insertion might affect the adaptability and stability of Tn6330. Taken together, these findings suggest that the IncHI2 plasmid might be a main factor affecting the transmission of mcr-1 in the chicken supply chain and that the genetic context of the mcr-1-bearing IncHI2 plasmid is constantly evolving.

Topics: Animals; Anti-Bacterial Agents; Chickens; China; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Plasmids

Topics: Animals; Anti-Bacterial Agents; Chromosomes, Bacterial; Colistin; Drug Resistance, Bacterial; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Plasmids; Swine; Swine Diseases; Taiwan; Transferases (Other Substituted Phosphate Groups); Whole Genome Sequencing

Microbiological and molecular genetic characterization resistance profiles of Escherichia coli strains isolated in a pilot single-center clinical study from patients of the urological department in Yaroslavl in 2016-2017.. Clinical strains of E. coli (n=18) were isolated from the urine of women aged 23-84 years. The mobility of bacteria, colicinogenicity, and sensitivity to lactobacilli antagonism, biofilm formation, and susceptibility to antimicrobials were evaluated. The antibiotic resistance genes were identified.. The E. coli strains had a wide heterogeneity in mobility, colicinogenicity, and biofilm formation. They were sensitive to Lactobacillus acidophilus antagonism, as well as to nitrofurantoin, meropenem, fosfomycin and the main functional classes of disinfectants and antiseptics, but are resistant to beta-lactams, fluoroquinolones and aminoglycosides. The mcr-1 gene providing resistance to colistin was identified in two strains.. Analysis of genetic antibiotic resistance determinants revealed the genetic diversity of clinical E. coli strains. The obtained data on the strain sensitivity to antibacterials and disinfectants can be used by clinicians in choosing the optimal antibiotic therapy and treatment of abiotic surfaces in urological departments.

Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Female; Humans; Microbial Sensitivity Tests; Middle Aged; Urologic Diseases; Young Adult

Topics: Animals; Anti-Bacterial Agents; Chickens; Colistin; Escherichia coli; Escherichia coli Infections; Gastrointestinal Microbiome; Intestines; Male; Paenibacillus; Poultry Diseases; Probiotics

Plasmid-mediated mechanisms of drug resistance accelerate the spread of polymyxin resistance, leaving clinicians with few or no antibacterial options for the treatment of infections caused by MDR bacteria, especially carbapenemase-producing strains.. To evaluate the associations among promoter sequence variation, mcr-1 expression, host factors and levels of colistin resistance and to propose antisense agents such as peptide nucleic acids (PNAs) targeting mcr-1 as a tool to restore colistin susceptibility through modulation of MCR-1 expression in Escherichia coli.. A β-galactosidase assay was performed to study mcr-1 promoter activity. Quantitative real-time PCR and western blot assays were used to identify the expression level of MCR-1 in WT strains and transformants. Three PNAs targeting different regions of mcr-1 were designed and synthesized to determine whether they can effectively inhibit MCR-1 expression. MIC was measured to test colistin susceptibility in the presence or absence of PNA-1 in mcr-1-carrying E. coli.. Variation in the mcr-1 promoter sequence and host species affect promoter activity, MCR-1 expression levels and colistin MICs. One PNA targeting the ribosome-binding site fully inhibited the expression of mcr-1 at a concentration of 4 μM, resulting in significantly increased susceptibility to colistin. The MIC90 of colistin decreased from 8 to 2 mg/L (P < 0.05) in the presence of 4 μM PNA.. These findings suggest that the antisense approach is a possible strategy to combat mcr-1-mediated resistance as well as other causes of emerging global resistance.

Topics: Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Microbial Sensitivity Tests; Peptide Nucleic Acids; Plasmids

The development of colistin resistance in carbapenem-resistant strains poses a serious public health problem. In this study, we collected 249 carbapenem-resistant Escherichia coli isolates from patients in Seoul in 2018, and screened all isolates for colistin resistance and for the presence of mobile colistin resistance (mcr) genes. Colistin-resistant strains were further analyzed using multilocus sequence typing, antimicrobial susceptibility testing, detection of antibiotic resistance determinants, plasmid transconjugation, and whole-genome sequencing. Three of the 249 carbapenem-resistant isolates were resistant to colistin, and mcr-1 was detected in one isolate (SECR18-0888), which belonged to sequence type 156 and was resistant to all antibiotics tested except tigecycline. The mcr-1.1 gene was located on an ~62 kb self-transferable IncI2 plasmid along with the bla

Topics: Anti-Bacterial Agents; beta-Lactamases; Carbapenems; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli Infections; Escherichia coli Proteins; Extraintestinal Pathogenic Escherichia coli; Genes, Bacterial; Humans; Microbial Sensitivity Tests; Multiplex Polymerase Chain Reaction; Plasmids; Republic of Korea; Whole Genome Sequencing

The rise of the plasmid-encoded colistin resistance gene

Topics: Animals; Anti-Bacterial Agents; Chickens; China; Colistin; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Feces; Gene Expression Regulation, Bacterial; Selection, Genetic

Topics: Anti-Bacterial Agents; China; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Microbial Sensitivity Tests; Plasmids; Tigecycline

Topics: Animals; Anti-Bacterial Agents; Bacterial Outer Membrane; Cell Membrane Permeability; Colistin; Disease Models, Animal; Drug Resistance, Bacterial; Drug Synergism; Drug Therapy, Combination; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Female; Humans; Melatonin; Mice; Microbial Sensitivity Tests; Plasmids

Antimicrobials are used to support livestock health and productivity, but might pose a risk for the development of antimicrobial resistance; in particular, when multiple livestock species are raised together in production systems. On integrated chicken-fish farms, chickens are raised over fish ponds and poultry faeces is excreted into the ponds. We investigated antimicrobial usage and the antimicrobial susceptibility of Escherichia coli cultured from poultry faeces on 301 integrated farms in Ayeyarwady Delta of Myanmar. Antimicrobials were used by 92.4% of farmers for chickens, but they were not applied to fish. The most common antimicrobials used were Octamix (amoxicillin and colistin sulfate) on 28.4%, enrofloxacin on 21.0% and amoxicillin on 16% of farms. Overall, 83.1% (152/183) of the E. coli were resistant to at least one antimicrobial. The highest level of resistance was to amoxicillin (54.6%), tetracycline (39.9%), sulfamethoxazole/trimethoprim (35.5%) and enrofloxacin (34.4%). Multidrug resistance was identified in 42.4% of isolates. In general, we found similar levels of antimicrobial resistance in non-users of antimicrobials as in users of antimicrobials for more commonly applied antimicrobials. Overall, antimicrobial resistance was lower in chickens on these integrated farms in Myanmar, compared to poultry farms in other countries of South East and East Asia.

Topics: Amoxicillin; Animal Husbandry; Animals; Anti-Bacterial Agents; Anti-Infective Agents; Aquaculture; Chickens; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Farmers; Farms; Fisheries; Livestock; Microbial Sensitivity Tests; Myanmar; Poultry; Poultry Diseases

Topics: Animals; Anti-Bacterial Agents; Auranofin; beta-Lactamase Inhibitors; beta-Lactamases; Carbapenems; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Female; Humans; Mice; Mice, Inbred BALB C; Microbial Sensitivity Tests

This report described the first Escherichia coli (E. coli) isolates harbouring mcr-1 in Uruguay.. Three E. coli isolates were obtained from blood, urine and rectal swabs from different patients in two hospitals. Extended-spectrum β-lactamases (ESBL), plasmid-encoded (pAmpC) β-lactamases, plasmid-mediated quinolone resistance (PMQR) genes, class 1 integrons, and mcr-1, mcr-2 and mcr-3 were sought and characterised in three E. coli isolates. Transfer of resistance determinants was assessed by conjugation. Clonality was analysed by multilocus sequence typing.. All isolates were categorised as being colistin-resistant and the mcr-1 gene was detected. Two isolates were also resistant to oxyimino cephalosporins: one on account of bla. ST10 is considered as a high-risk clone worldwide. This type of mcr-1-harbouring clone is a major concern for human and animal health and must be under close surveillance. This study detected the presence of mcr-1 for the first time in Uruguay, albeit in an allodemic manner, associated with different antibiotic-resistance genes and from diverse clinical contexts. Considering that colistin is often the last therapeutic option available for multidrug-resistant Gram-negative bacilli infections, it is important to maximise precautions to avoid dissemination of isolates carrying mcr-1.

Topics: Adult; Aged, 80 and over; Cephalosporins; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Female; Gene Transfer, Horizontal; Humans; Male; Multilocus Sequence Typing; Rectum; Retrospective Studies; Uruguay

Topics: Animals; beta-Lactamases; Cattle; Cattle Diseases; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Feces; Tunisia

Polymyxin antibiotics are a last-line treatment for multidrug-resistant Gram-negative bacteria. However, the emergence of colistin resistance, including the spread of mobile

Topics: Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Microbial Sensitivity Tests; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

Topics: Aged; Algeria; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli Infections; Escherichia coli Proteins; Hospitals; Humans; Male; Plasmids; Urinary Tract Infections; Uropathogenic Escherichia coli

The convergence of high virulence and multidrug resistance (MDR) in Gram-negative pathogens circulating at the human-animal interface is a critical public health issue. We hereby report the genomic characteristics and virulent behavior of a colistin-resistant Escherichia coli, serotype ONT:H26, belonging to ST6395, isolated from a healthy broiler in Pakistan. This strain harbored multiple antimicrobial resistance genes, including mcr-1.1 and blaCARB-2, besides cma (colicin M) and astA [heat-stable enterotoxin 1 (EAST1) toxin] virulence genes. In vivo experiments carried out with the Galleria mellonella infection model revealed that MCR-1-positive E. coli ST6395 killed 96.4% of the larvae at 18 hour post-infection. Interplay between resistance and virulence in clinically important pathogens could be a potential threat, representing a serious challenge to global public health.

Topics: Animals; Anti-Bacterial Agents; Chickens; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Genomics; Pakistan; Poultry Diseases; Virulence; Virulence Factors

The emergence of plasmid mediated mcr in bacteria has become global public health threat. Herein, we report a mcr-1 positive E. coli in normal human flora from a patient admitted in Dhaka Medical College Hospital (DMCH).. In total, 700 non-duplicate rectal swabs were collected from DMCH during 13th May to 12th June 2018. E. coli from rectal swabs were isolated on chromogenic UTI media containing vancomycin 10mg/l (Liofilchem, Italy) and confirmed by MALDI-TOF. Minimum inhibitory concentrations (MIC) were determined by agar dilution and interpreted according to EUCAST breakpoints. Genomic analysis of mcr positive E. coli (MCRPEC) was performed by Illumina MiSeq sequencing and pulsed field gel electrophoresis (PFGE) using S1 nuclease DNA digests and blamcr-1 probing. Transferability of blamcr-1 were determined by conjugation assays.. We found one MCRPEC from 700 rectal swab screening which was isolated from the rectal swab culture of a 17-year boy who was admitted to the burns ICU, DMCH with 53% flame burn involving much of the trunk and face. Genome sequencing revealed that mcr-1 was present on an IncH12 plasmid of 257,243 bp and flanked by ISApaI1. The colistin resistance can be transferred to the recipient Klebsiella varricola with a frequency of 8.3 × 10-5. Transconjugants were more resistant to colistin than donor (MIC 32 µg/mL).. This is the first human associated mcr in Bangladesh. These data indicate the need for a systematic "one health" surveillance in the country.

Topics: Anti-Bacterial Agents; Bangladesh; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Hospitals; Humans; Microbial Sensitivity Tests; Plasmids

Escherichia coli is one of the major pathogens in humans and animals causing localized and systemic infections, which often lead to acute inflammation, watery diarrhea, and hemorrhagic colitis. Bacterial lipopolysaccharide (LPS) and Shiga exotoxins (Stx) are mostly responsible for such clinical signs. Therefore, highly effective treatment of E. coli infections should include both eradication of bacteria and neutralization of their toxins. Here, for the first time, we compared the in vitro ability of common antibiotics to decrease LPS- and Stx-mediated cytotoxicity: colistin, amoxicillin (used separately or combined), enrofloxacin, and its metabolite ciprofloxacin. Three experimental scenarios were realized as follows: (a) the direct effect of antibiotics on endotoxin, (b) the effect of antibiotic treatment on LPS-mediated cytotoxicity in an experiment mimicking "natural infection," (c) the effect of antibiotics to decrease Stx2e-mediated cytotoxicity. Two cell lines, A549 and Vero cells, were used to perform cytotoxic assays with the methyl tetrazolium (MTT) and lactate dehydrogenase leakage (LDH) methods, respectively. Colistin and amoxicillin, especially used in combination, were able to attenuate LPS toxic effect, which was reflected by increase in A549 cell viability. In comparison with other antibiotics, the combination of colistin and amoxicillin exhibited the highest boster or additive effect in protecting cells against LPS- and Stx2e-induced toxicity. In summary, in comparison with fluoroquinolones, the combination of colistin and amoxicillin at concentrations similar to those achieved in plasma of treated animals exhibited the highest ability to attenuate LPS- and Stx2e-mediated cytotoxicity.

Topics: A549 Cells; Amoxicillin; Animals; Anti-Bacterial Agents; Chlorocebus aethiops; Ciprofloxacin; Colistin; Dose-Response Relationship, Drug; Drug Combinations; Enrofloxacin; Escherichia coli Infections; Humans; In Vitro Techniques; Lipopolysaccharides; Shiga Toxin; Shiga-Toxigenic Escherichia coli; Vero Cells

The emergence of NDM- and MCR-1-co-producing Escherichia coli has compromised the use of carbapenems and colistin, which are critically important in clinical therapy, and represents a severe threat to public health worldwide. Here, we demonstrate synergism of colistin combined with existing antibiotics as a potential strategy to overcome XDR E. coli co-harbouring NDM and MCR-1 genes.. To comprehensively evaluate their combined activity, antibiotic combinations were tested against 34 different E. coli strains carrying both NDM and MCR-1 genes. Antibiotic resistance profiles and molecular characteristics were investigated by susceptibility testing, PCR, MLST, S1-PFGE and WGS. Antibiotic synergistic efficacy was evaluated through in vitro chequerboard experiments and dose-response assays. A mouse model was used to confirm active combination therapies. Additionally, combinations were tested for their ability to prevent high-level colistin-resistant mutants (HLCRMs).. Combinations of colistin with rifampicin, rifabutin and minocycline showed synergistic activity against 34 XDR NDM- and MCR-1-co-producing E. coli strains, restoring, in part, susceptibility to both colistin and the partnering antibiotics. The therapeutic effectiveness of colistin combined with rifampicin or minocycline was demonstrated in a mouse model. Furthermore, colistin plus rifampicin showed significant activity in preventing the occurrence of HLCRMs.. The synergism of colistin in combinations with rifampicin, rifabutin or minocycline offers viable therapeutic alternatives against XDR NDM- and MCR-positive E. coli.

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Colistin; Disease Models, Animal; Drug Resistance, Bacterial; Drug Synergism; Drug Therapy, Combination; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Female; Genotyping Techniques; Mice, Inbred ICR; Microbial Sensitivity Tests; Treatment Outcome

We screened, for the first time, plasmid-mediated colistin resistance mcr-3 genes among 636 Escherichia coli isolates collected from swine in South Korea. Whole-genome sequencing showed that the E. coli strain harbored the mcr-3 gene in a p17S-208 plasmid with an IncHI2-ST3 plasmid type and a size of 260,399 base pairs. The deduced amino acid sequences revealed that persistent evolution in the bacterial genome has resulted in mcr gene variants. There is a need for extensive surveillance to prevent the dissemination of colistin resistance mcr genes from animal to human.

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Genome, Bacterial; Microbial Sensitivity Tests; Plasmids; Republic of Korea; Swine; Transferases (Other Substituted Phosphate Groups)

In recent years, several plasmids harbouring genes encoding phosphoethanolamine transferases conferring colistin resistance have been described in multiple Enterobacteriaceae species. Avian Pathogenic E. coli (APEC) causes colibacillosis and is responsible for a considerable proportion of the disease burden in commercial poultry flocks, and may be linked to zoonotic infections in humans. Here, we describe the genotypic and phenotypic characteristics of a multidrug-resistant APEC ST69 isolate (APECA2), recovered in 2016 from a diseased broiler at post-mortem examination in Germany. The isolate was resistant to several antibiotics of human and veterinary importance, including colistin. The mcr-1 gene was detected on a mobile genetic element located on an IncHI2/ST4 plasmid, which was characterized using long-read Nanopore and short-read Illumina sequencing of purified plasmid. Isolate APECA2 displayed resistance to chicken serum and harbours numerous virulence genes. This study highlights the public health importance of enhanced antimicrobial resistance surveillance and strict antimicrobial stewardship in human and veterinary healthcare.

Topics: Animals; Anti-Bacterial Agents; Chickens; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Genotype; Germany; Plasmids; Poultry Diseases; Virulence

Escherichia coli isolates carrying the mcr-1 gene are rarely reported in diarrhoeal patients. Here we report the draft genome sequence of a colistin-resistant E. coli isolated from a hospitalised patient with acute diarrhoea in Thailand.. Whole genomic DNA of the colistin-resistant E. coli isolate (MSF11) was extracted and was sequenced using an Ion Torrent sequencer with 400-bp read chemistry. The draft genome sequence of MSF11 was analysed with regard to multilocus sequence type (ST), serotype, acquired antimicrobial resistance genes, plasmid replicon types and virulence genes using tools from the Center for Genomic Epidemiology.. E. coli strain MSF11 was serotype OUT:H10 and ST226. Acquired antimicrobial resistance genes [bla. An mcr-1 variant was identified in an E. coli isolate harbouring the EAST1 (enteroaggregative E. coli heat-stable toxin 1) gene (astA) from a human diarrhoeal stool specimen. This study highlights the potential risk of dissemination of colistin-resistant E. coli in view of the prevalence of the variant gene on IncX4-type plasmids.

Topics: Acute Disease; Anti-Bacterial Agents; Bacterial Typing Techniques; Colistin; Diarrhea; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Female; Genetic Variation; Genome, Bacterial; Humans; Microbial Sensitivity Tests; Middle Aged; Multilocus Sequence Typing; Plasmids; Thailand; Whole Genome Sequencing

Four

Topics: Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Microbial Sensitivity Tests; Plasmids; Sequence Analysis, DNA; Whole Genome Sequencing

Topics: Animals; Anti-Bacterial Agents; Argentina; beta-Lactamases; Cats; Cephalosporins; Colistin; Dogs; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Microbial Sensitivity Tests; Pets; Phylogeny; Plasmids; Urinary Tract Infections

The aim of this study was to assess the presence of mobile colistin resistance in bacteria isolated from the swine production environment and to analyze the genomic environment of the new colistin resistance gene mcr-3. Anal swabs and environmental samples were collected from a commercial pig farm. Direct sample testing (DST) for mcr genes and isolation of colistin-resistant isolates was performed. The mcr-3-positive isolates were subjected to whole genome sequencing (WGS). Transferability and genomic location analyses of mcr-3 gene were performed using conjugation and S1 nuclease-PFGE with Southern blotting assays, respectively. The antimicrobial susceptibility profiles of the mcr-carrying isolates were determined using the agar dilution method. A total of 65 samples were collected. The DST rates of mcr-1 (64.6%, 42/65) and mcr-3 (40.0%, 26/65) were considerably higher than the rates of mcr-1-positive E. coli (49.2%, 32/65) and mcr-3-positive E. coli (7.7%, 5/65) isolated from these samples, respectively. The five mcr-3-positive isolates were derived from different sources (pig, fly and soil) and four of the five isolates were also positive for mcr-1. The mcr-3 genes were located on IncP-1 plasmids in three isolates or IncHI2 plasmids in two isolates. Several mobile elements, including IS4321, ΔTnAs2 or ISKpn40, were identified in the flanking regions of mcr-3 in the E. coli isolates. In conclusion, the mobile colistin resistance genes mcr-1 and mcr-3 are prevalent in the monitored pig farm and its surrounding environment. Due to their location on broad-host range IncP-1 plasmids and their proximity to different IS sequences, mcr-3 gene might have excellent opportunities for transmission.

Topics: Animals; Anti-Bacterial Agents; China; Colistin; Conjugation, Genetic; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Farms; Feces; Gene Transfer, Horizontal; Interspersed Repetitive Sequences; Livestock; Microbial Sensitivity Tests; Swine; Transferases (Other Substituted Phosphate Groups); Whole Genome Sequencing

Topics: Animals; Anti-Bacterial Agents; China; Chromosomes, Bacterial; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Geese

The identification of colistin-resistant enterobacteria in veterinary medicine is impaired by the absence of first-line reliable phenotypic assay. The purpose of this study was to assess two selective agar media for the detection of colistin-resistant bovine pathogenic Escherichia coli. A total of 158 E. coli (46 R , 96 I and 16 S at the disk diffusion assay) isolated between 2013 and 2018 from <3 month-old calves suffering enteritis or septicaemia, were (i) tested by the broth dilution assay to determine colistin Minimal Inhibitory Concentrations (MIC); (ii) streaked on CHROMID® Colistin_R and CHROMagar™ COL-APSE agar plates; (iii) submitted to a pentaplex PCR to identify the presence of mcr-1 to mcr-5 genes. Of the 92 E. coli growing on both agar media, 90 had a MIC > 2.0 μg/ml as had the 3 E. coli that grew only on the CHROMID® Colistin_R agar medium and one E. coli that grew on neither agar media. Therefore, the positive predictive values of the CHROMID® Colistin_R and CHROMagar™ COL-APSE agar media were both 0.98 whereas their negative predictive values were 0.98 and 0.94, respectively. Also noteworthy 43 of the 46 R isolates had a MIC > 2.0 μg/ml and grew on both selective media as did half of the 96 I isolates and only 1 of the S isolates. Conversely, only 30 of the 90 isolates that grew on both agar media and with a MIC > 2.0 μg/ml tested positive for the mcr-1 or mcr-2 genes with the pentaplex PCR. These two selective agar media can be used to reliably detect colistin-resistant E. coli. Positive growth was highly correlated with R results at the disk diffusion assay, but not with the presence of mcr genes.

Topics: Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; Colistin; Colony Count, Microbial; Culture Media; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Microbial Sensitivity Tests

Topics: Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Genetic Variation; Humans; Klebsiella Infections; Klebsiella pneumoniae; Microbial Sensitivity Tests; Plasmids; Prevalence

Topics: Animal Husbandry; Animals; Anti-Bacterial Agents; China; Colistin; Drug Resistance, Bacterial; Drug Utilization; Escherichia coli; Escherichia coli Infections; Farms; Prevalence; Swine

IntroductionEmergence of resistance determinants of

Topics: Anti-Bacterial Agents; Bacterial Proteins; beta-Lactamases; China; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Food Microbiology; Humans; Microbial Sensitivity Tests; Plasmids; Polymerase Chain Reaction; Prevalence; Sequence Analysis, DNA

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Livestock; Plasmids; Rural Population; Vietnam

Bacterial infections in immunocompromised patients are associated with a high mortality and morbidity rate. In this high-risk group, the presence of multidrug-resistant (MDR) bacteria, particularly bacteria that harbor a transferable antibiotic resistance gene, complicates the management of bacterial infections. In this study, we investigated the presence of the transferable colistin resistance mcr genes in patients with leukemia in Spain.. 217 fecal samples collected in 2013-2015 from 56 patients with acute leukemia and colonized with MDR Enterobacteriaceae strains, were screened on September 2017 for the presence of the colistin resistance mcr genes (mcr-1 to -5) by multiplex PCR. mcr positive strains selected on LBJMR and MacConkey supplemented with colistin (2 μg/ml) media were phenotypically and molecularly characterized by antimicrobial susceptibility testing, minimum inhibitory concentration, multilocus sequence typing and plasmid characterization.. Among 217 fecal samples, 5 samples collected from 3 patients were positive for the presence of the mcr-1 colistin-resistance gene. Four Escherichia coli strains were isolated and exhibited resistance to colistin with MIC = 4 μg/ml. Other genes conferring the resistance to β-lactam antibiotics have also been identified in mcr-1 positive strains, including bla. To the best of our knowledge, we have identified the mcr-1 gene for the first time in leukemia patients in Spain. In light of these results, strict measures have been implemented to prevent its dissemination.

Topics: Anti-Bacterial Agents; beta-Lactamases; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Leukemia; Microbial Sensitivity Tests; Middle Aged; Plasmids; Spain

Topics: Animals; Chickens; Colistin; Dietary Supplements; Eating; Escherichia coli; Escherichia coli Infections; Gene Expression Regulation; Intestines; Poultry Diseases; Probiotics; Synbiotics; Weight Gain

The last few years have seen the emergence of multi-drug resistant (MDR) Gram-negative infections, which are associated with high morbidity and mortality. The indiscriminate use of colistin has led to the development of resistance, which can be diagnosed effectively by broth microdilution. Studies from India are limited, and this study was conducted in order to determine the prevalence and risk factors associated with colistin resistance.. Urine samples from patients admitted with urinary tract infection (UTI), growing MDR Escherichia coli and Klebsiella pneumoniae, were tested for the minimum inhibitory concentration (MIC) of colistin by broth microdilution. Isolates with an MIC >2 µg ml. Two hundred and fifty MDR isolates (E. coli=142/2319 and K.pneumoniae=108/775) from 216 patients were selected from the 25 046 isolates screened. Twenty-five isolates (20 K.pneumoniae and 5 E. coli) were resistant to colistin, with a prevalence of 3.52  % in E. coli and 18.5  % in K. pneumoniae among the MDR isolates. PCR for the mcr1 and mcr2 genes was negative. Multivariate regression showed that multiple episodes of hospitalization, hospital stay >2 weeks, exposure to >three antibiotic classes and abnormality/surgery of the lower urinary tract were the significant risk factors for colistin resistance. Previous use of colistin and colistin resistance had a significant effect on all outcomes.. K. pneumoniae show six times higher prevalence of colistin resistance than E. coli, and the emergence of resistant organisms has led to an increase in morbidity in infected patients.

Topics: Adult; Anti-Bacterial Agents; Bacterial Proteins; Case-Control Studies; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Female; Humans; India; Klebsiella Infections; Klebsiella pneumoniae; Male; Middle Aged; Prevalence; Risk Factors; Urinary Tract Infections; Young Adult

Plasmid-mediated colistin resistance of the mobile colistin resistance (MCR) type is a growing concern in

Topics: Animals; Anti-Bacterial Agents; Colistin; DNA Transposable Elements; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; France; Microbial Sensitivity Tests; Plasmids; Swine; Transferases (Other Substituted Phosphate Groups)

This study investigated the prevalence of Escherichia coli (E. coli) colistin resistance and mcr-1 and mcr-2 genes among extended-spectrum β-lactamase (ESBL)/AmpC-producing E. coli isolates recovered from chicken feces in Canada (Quebec), Senegal and Vietnam, and evaluated the susceptibility pattern of the colistin-resistant E. coli isolates to other clinically relevant antimicrobials.. A total of 327 potential ESBL/AmpC-producing E. coli isolates from chicken farms in Canada (Quebec), Senegal and Vietnam were analysed for colistin susceptibility by broth microdilution method and for the presence of mcr (1-2) genes by PCR. The pmrA and pmrB genes of colistin-resistant E. coli isolates, in the absence of mcr (1-2) genes, were sequenced. Antimicrobial resistance phenotypes of colistin-resistant E. coli isolates were determined by disk diffusion.. None of the 108 potential ESBL/AmpC-producing E. coli isolates from seven farms in Canada were colistin-resistant or possessed mcr-1 or mcr-2 gene. A low prevalence of 2.2% of colistin resistance was observed in 93 Senegalese isolates from the 15 sampled farms, although neither mcr-1 nor mcr-2 gene was found. A prevalence of 8.7% of colistin resistance was observed among 126 Vietnamese isolates from two of the four sampled farms. The mcr-1 gene was detected in 85% of the 13 phenotypically colistin-resistant isolates. Moreover, all colistin-resistant isolates presented a multidrug-resistant phenotype.. The co-existence of the mcr-1 and ESBL/AmpC genes and the very high level of multiple drug resistance in all colistin-resistant E. coli isolates obtained from sampled chicken farms in Vietnam is a major concern.

Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; beta-Lactamases; Chickens; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Farms; Feces; Membrane Proteins; Microbial Sensitivity Tests; Poultry Diseases; Prevalence; Quebec; Senegal; Vietnam

We tested extended-spectrum β-lactamase producing bacteria from wild gulls (Larus spp.) sampled in 2009 for the presence of mcr-1. We report the detection of mcr-1 and describe genome characteristics of four Escherichia coli and one Klebsiella pneumoniae isolate from Spain and Portugal that also exhibited colistin resistance. Results represent the earliest evidence for colistin-resistant bacteria in European wildlife.

Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; beta-Lactamases; Bird Diseases; Charadriiformes; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Klebsiella Infections; Klebsiella pneumoniae; Microbial Sensitivity Tests; Portugal; Spain

Clinical Enterobacteriacae isolates with a colistin minimum inhibitory concentration (MIC) ≥4 mg/L from a United States hospital were screened for the mcr-1 gene using real-time polymerase chain reaction (RT-PCR) and confirmed by whole-genome sequencing. Four colistin-resistant Escherichia coli isolates contained mcr-1. Two isolates belonged to the same sequence type (ST-632). All subjects had prior international travel and antimicrobial exposure.

Topics: Aged; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Female; Humans; Male; Michigan; Microbial Sensitivity Tests; Whole Genome Sequencing; Young Adult

The gene

Topics: Animal Migration; Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Microbial Sensitivity Tests; Plasmids; Raptors; Russia; Whole Genome Sequencing

Topics: Animals; Anti-Bacterial Agents; Birds; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Genes, Bacterial; Microbial Sensitivity Tests; Plasmids; Thailand

Topics: Aged; Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Female; Humans; Microbial Sensitivity Tests; New Zealand; Plasmids; Transferases (Other Substituted Phosphate Groups)

In this study, we assessed the selective effect of colistin administered orally to healthy weaned piglets harbouring an intestinal mcr-1-positive Escherichia coli strain. Maximum recommended dose and a higher dose often used in European pig farms were given by gavage. No selection of the mcr-1-positive strain was observed in our controlled conditions, irrespective of the dose. Further investigations in real farming conditions seem necessary.

Topics: Administration, Oral; Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Farms; Feces; Intestines; Rifampin; Swine

Within the scope of a cross-sectional investigation on fattening pig farms conducted in 2011 and 2012, 48 fattening farms in different agricultural regions of Germany were sampled. Primary cultures of boot swabs and collective faecal samples were stored at -80 °C and screened for the presence of the mcr-1 colistin-resistance gene. The laboratory results were linked to farm-related data collected via questionnaire. Logistic regression models were used to investigate the association between occurrence of mcr-1 and farm-related data. Escherichia coli carrying the mcr-1 gene were isolated from 26 of 216 (12.0%) mixed bacterial cultures originating from 12 of 48 (25.0%) farms. Results of the logistic regression analyses indicate that the transmission between pigs or their direct environment is crucial for the occurrence of these resistant bacteria. However, there was no statistically significant association between antimicrobial use and the occurrence of the mcr-1 gene.

Topics: Animals; Anti-Bacterial Agents; Colistin; Cross-Sectional Studies; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Farms; Feces; Germany; Microbial Sensitivity Tests; Swine

To identify plasmid-mediated colistin resistance in clinical Enterobacteriaceae isolates in Oman, where this resistance mechanism has not been encountered yet.. Twenty-two colistin-resistant Enterobacteriaceae clinical isolates collected between July 2014 and June 2016 in a tertiary care hospital in Muscat were screened by PCR for the mcr-1 and mcr-2 genes. The strain identified as mcr-1 positive was genotyped and its antibiotic susceptibility was established. The mcr-1 containing plasmid was mobilized into Escherichia coli K-12 and its sequence was determined.. A single E. coli isolate (OM97) carrying mcr-1 gene was identified, while no strains carrying the mcr-2 gene was found. E. coli OM97 was isolated in June 2016 from blood culture of a male patient with multiple comorbidities. It belonged to ST10. Beyond colistin, it was resistant to amoxicillin-clavulanic acid, piperacillin-tazobactam, amikacin, ciprofloxacin, tetracycline, and cotrimoxazole. The mcr-1 gene was located on a conjugative IncI2-type plasmid of 63722 bp size, which did not harbor any further resistance genes. The genetic surrounding of the mcr-1 gene lacked the ISApl1 element.. Although colistin resistance caused by the mcr-1 gene is not common in our collection of clinical isolates, the occurrence of the plasmid-mediated colistin resistance in an E. coli ST10 strain is of concern as this clonal group was already shown to spread ESBL genes and quinolone resistance worldwide. It is especially worrisome that as the mcr-1 gene occurred in a non-ESBL, carbapenem-susceptible E. coli strain, current susceptibility testing algorithms may not detect its presence.

Topics: Amikacin; Amoxicillin-Potassium Clavulanate Combination; Anti-Bacterial Agents; Bacteremia; Ciprofloxacin; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Gene Expression; Humans; Membrane Proteins; Microbial Sensitivity Tests; Oman; Penicillanic Acid; Piperacillin; Piperacillin, Tazobactam Drug Combination; Plasmids; Protein Isoforms; Tetracycline; Trimethoprim, Sulfamethoxazole Drug Combination

To evaluate a novel method, the colistin-MAC test, for phenotypic screening of acquired colistin resistance mediated by transferable mcr-1 resistance determinants, based on colistin MIC reduction in the presence of dipicolinic acid (DPA).. The colistin-MAC test consists in a broth microdilution method, in which colistin MIC is tested in the absence or presence of DPA (900 μg/mL). Overall, 74 colistin-resistant strains of Enterobacteriaceae (65 Escherichia coli and nine other species), including 61 strains carrying mcr-1-like genes and 13 strains negative for mcr genes, were evaluated with the colistin-MAC test. The presence of mcr-1-like and mcr-2-like genes was assessed by real-time PCR and end-point PCR. For 20 strains, whole-genome sequencing data were also available.. A ≥8-fold reduction of colistin MIC in the presence of DPA was observed with 59 mcr-1-positive strains, including 53 E. coli of clinical origin, three E. coli transconjugants carrying MCR-1-encoding plasmids, one Enterobacter cloacae complex and two Citrobacter spp. Colistin MICs were unchanged, increased or at most reduced by twofold with the 13 mcr-negative colistin-resistant strains (nine E. coli and four Klebsiella pneumoniae), but also with two mcr-1-like-positive K. pneumoniae strains.. The colistin-MAC test could be a simple phenotypic test for presumptive identification of mcr-1-positive strains among isolates of colistin-resistant E. coli, based on a ≥8-fold reduction of colistin MIC in the presence of DPA. Evaluation of the test with a larger number of strains, species and mcr-type resistance determinants would be of interest.

Topics: Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Genes, Bacterial; Humans; Microbial Sensitivity Tests; Phenotype

Topics: Animals; Anti-Bacterial Agents; Cathelicidins; Cattle; Colistin; Drug Resistance, Bacterial; Endopeptidases; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Germany; Microbial Sensitivity Tests; Recombinant Fusion Proteins; Swine

The increase in multidrug-resistant Gram-negative bacterial infections has forced the reintroduction of antibiotics such as colistin. However, the spread of the plasmid-borne mcr-1 colistin resistance gene have moved us closer to an era of untreatable Gram-negative infections. To evaluate whether predatory bacteria could be used as a potential therapeutic to treat this upcoming threat, the ability of Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus to prey on several clinically relevant mcr-1-positive, colistin-resistant isolates was evaluated. No change in the ability of the predators to prey on free swimming and biofilms of prey cells harboring mcr-1 was measured, as compared to their mcr-1 negative strain.

Topics: Alphaproteobacteria; Anti-Bacterial Agents; Antibiosis; Bdellovibrio bacteriovorus; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans

Topics: Aged; Aged, 80 and over; Anti-Bacterial Agents; beta-Lactamases; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Male; Switzerland; Urinary Tract Infections

Topics: beta-Lactamases; Colistin; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans

Topics: Animals; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Japan; Microbial Sensitivity Tests; Prevalence; Swine; Swine Diseases

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Cattle; Cattle Diseases; Colistin; Drug Resistance, Bacterial; Epidemics; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; France; Genotype; Microbial Sensitivity Tests; Topography, Medical; Transferases (Other Substituted Phosphate Groups)

We evaluate here the presence of the mcr-1-like and mcr-2 genes in Escherichia coli and Salmonella spp. isolated from healthy food-producing animals at slaughter between 2002 and 2014 in Europe. Isolates were retrieved from cattle, pig and chicken from 11 European countries of production. The susceptibility to colistin and antibiotics used in human medicine was determined by agar dilution. Colistin-resistant isolates were PCR-screened for mcr genes. mcr-positive isolates were typed by Pulsed-Field Gel Electrophoresis (PFGE) and Multi-Locus Sequence Typing. Among the 10,206 E. coli and 1774 Salmonella spp. isolated from cattle, pigs and chickens, 148 E. coli and 92 Salmonella spp. isolates were resistant to colistin. We found mcr-1-like gene in 68 (0.7%) E. coli and 2 (0.1%) Salmonella isolates whereas none of the isolates tested positive for mcr-2. MCR-1-like-positive E. coli were isolated from 2008 to 2014 in chicken (n=44, 1.2%) and pigs (n=24, 0.7%). The presence of mcr-1-like varied from 0 to 4.0% depending on the year and the animal species. mcr-1-like-positive isolates came from animals originating from Germany (n=38), Spain (n=23), The Netherlands (n=5), and France (n=4). They were distributed in 63 different PFGE types and 37 different STs, with ST10 being the most prevalent. The two mcr-1-like-positive Salmonella spp. were isolated from France and Germany from a pig and a chicken, respectively. mcr-1-like gene is present in food-producing animals at slaughter in European countries with the highest occurrence in chickens. The high clonal diversity of E. coli underlines the evidence for horizontal transfer of mcr-1-like genes.

Topics: Abattoirs; Animals; Anti-Bacterial Agents; Bacterial Proteins; Bacterial Typing Techniques; Cattle; Chickens; Colistin; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Europe; Multilocus Sequence Typing; Salmonella; Salmonella Infections, Animal; Swine

The presence of the

Topics: Animals; Anti-Bacterial Agents; Aquaculture; beta-Lactams; Carps; China; Chromosomes, Bacterial; Colistin; Drug Resistance, Bacterial; Epidemiological Monitoring; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Fish Diseases; Fluoroquinolones; Gene Expression; Microbial Sensitivity Tests; Plasmids

Six imported pigs originating from Guangdong, Henan, and Hunan provinces in China during October 2015 to February 2017 were cultured and found to be positive for meropenem-resistant

Topics: Animal Husbandry; Animals; Anti-Bacterial Agents; beta-Lactamases; Carbapenems; China; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Farms; Gene Expression; Plasmids; Replicon; Swine

Topics: Animals; Anti-Bacterial Agents; Chickens; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Lebanon; Plasmids; Poultry; Poultry Diseases

mcr-1.2, an allelic variant of the transferable colistin resistance gene mcr-1, was characterized in a colistin-resistant blood isolate of Escherichia coli. It was harbored by an IncX4-type plasmid (33,293 bp). Despite its low prevalence, the potentially worrying spread of the mcr-1 gene, particularly its mcr-1.2 variant, in Italy requires increasing surveillance.

Topics: Alleles; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Female; Humans; Italy; Microbial Sensitivity Tests; Middle Aged; Plasmids

Two colistin-resistant Escherichia coli strains (FS13Z2S and FS3Z6C) possessing chromosomally encoded mcr-1 isolated from swine were characterised. Whole-genome sequencing revealed that in strain FS13Z2S mcr-1 occurred in triplicate in the chromosome with another copy encoded on a pHNSHP45-2-like IncHI2 plasmid, whereas in strain FS3Z6C only one copy mcr-1 was inserted in the chromosome. It seems likely that the triplication of chromosomal copies of mcr-1 in FS13Z2S is due to intramolecular transposition events via a composite transposon containing an mcr-1 cassette bracketed by two copies of insertion sequence ISApl1, and the pap2 gene at the insertion site was truncated by an IS1294-like element. In plasmid pFS13Z2S and the chromosome of strain FS3Z6C, only a single copy of ISApl1 was present upstream of the mcr-1 cassette. The two strains exhibited similar colistin minimum inhibitory concentrations (MICs) and featured phosphoethanolamine addition to lipid A, without regard to the copy number of mcr-1. The mcr-1-harbouring plasmid was unstable in wild-type strain FS13Z2S and was quickly lost after 7 days of passage on colistin-free Luria-Bertani broth containing 0.5% SDS, but the mcr-1 copies on the chromosome persisted. These results reveal that the single copy of mcr-1 could result in modification of lipopolysaccharide (LPS) and cause colistin resistance in E. coli. Acquisition of multiple copies of mcr-1, especially on the chromosome, would facilitate stable persistence of colistin resistance in the host strain.

Topics: Anti-Bacterial Agents; Base Sequence; Colistin; DNA Transposable Elements; DNA, Bacterial; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Ethanolamines; Gene Dosage; Humans; Lipid A; Microbial Sensitivity Tests; Plasmids; Sequence Analysis, DNA

Topics: Anti-Bacterial Agents; beta-Lactamases; Child, Preschool; Colistin; Drug Resistance, Multiple, Bacterial; Enterobacteriaceae; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Male

Plasmid-borne colistin resistance mediated by mcr-1 may contribute to the dissemination of pan-resistant Gram-negative bacteria. Here, we show that mcr-1 confers resistance to colistin-induced lysis and bacterial cell death, but provides minimal protection from the ability of colistin to disrupt the Gram-negative outer membrane. Indeed, for colistin-resistant strains of Enterobacteriaceae expressing plasmid-borne mcr-1, clinically relevant concentrations of colistin potentiate the action of antibiotics that, by themselves, are not active against Gram-negative bacteria. The result is that several antibiotics, in combination with colistin, display growth-inhibition at levels below their corresponding clinical breakpoints. Furthermore, colistin and clarithromycin combination therapy displays efficacy against mcr-1-positive Klebsiella pneumoniae in murine thigh and bacteremia infection models at clinically relevant doses. Altogether, these data suggest that the use of colistin in combination with antibiotics that are typically active against Gram-positive bacteria poses a viable therapeutic alternative for highly drug-resistant Gram-negative pathogens expressing mcr-1.

Topics: Animals; Anti-Bacterial Agents; Bacteremia; Colistin; Drug Resistance, Bacterial; Drug Therapy, Combination; Enterobacter aerogenes; Enterobacter cloacae; Enterobacteriaceae; Enterobacteriaceae Infections; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Ethanolaminephosphotransferase; Klebsiella Infections; Klebsiella pneumoniae; Mice; Microbial Sensitivity Tests

Colistin has been used as the last-line antibiotic for Escherichia coli infections. Herein, we collected 102 E. coli isolates from diseased pigs and 204 from healthy ones in Henan province of China. Then, we screened antimicrobial resistance and mcr-1 of bacteria. There was 25.5% (78/306) mcr-1-positive porcine E. coli, in which 46 isolates (45.1%, 46/102) were obtained from diseased pigs; the others (15.7%, 32/204) were collected from healthy pigs (45.1% versus 15.7%, P=0.000). Meanwhile, the former presented more serious resistance to colistin, ceftiofur, cefquinome, gentamicin, amikacin, doxycycline, florfenicol, enrofloxacin, and olaquindox than those from healthy pigs, which were similar to the relations between isolates with or without mcr-1, except for amikacin and doxycycline. Also, the resistance profiles of mcr-1-positive E. coli were more extensive than those of mcr-1-negative isolates.

Topics: Animals; Anti-Bacterial Agents; China; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Prevalence; Swine

Our study aimed to investigate colistin resistance and the mechanisms involved in a collection of 35 extended-spectrum beta-lactamase (ESBL) and 13 CMY-2-producing E. coli strains which were previously recovered from chicken gut microbiota in Tunisia, as well as to determine the genetic location of mcr genes. Forty-eight ESBL and CMY-2-producing E. coli strains were obtained from 137 fecal samples of healthy chickens during 2013. These strains were tested for colistin resistance by the broth microdilution method, and screened for mcr-1 and mcr-2 genes by PCR. Two of these strains were colistin-resistant (MIC = 8 mg/L). Both harbored the mcr-1 gene, were CMY-2 producers, and were additionally resistant to tetracycline, ciprofloxacin, chloramphenicol, gentamicin, tobramycin and trimethoprim-sulfamethoxazole. They shared phylogroup A, the same pulsed-field gel electrophoresis (PFGE)-pattern, and were typed as ST2197. In both strains, ISApl1 and pap2 were detected upstream and downstream of mcr-1 gene, respectively. The analysis of the two mcr-1-positive strains and their transconjugants by PCR-based replicon typing and S1-PFGE, demonstrated that mcr-1 gene is linked to an IncP plasmid (~242 kb), and bla

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Chickens; Colistin; Drug Resistance, Multiple, Bacterial; Electrophoresis, Gel, Pulsed-Field; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Farms; Feces; Gastrointestinal Microbiome; Gastrointestinal Tract; Humans; Microbial Sensitivity Tests; Plasmids; Poultry; Trimethoprim, Sulfamethoxazole Drug Combination; Tunisia

Topics: Animal Diseases; Animals; Anti-Bacterial Agents; Blood; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Food Microbiology; Genotype; Germany; Polymerase Chain Reaction; Sequence Analysis, DNA; Sequence Homology; Transferases (Other Substituted Phosphate Groups)

Topics: Animals; Anti-Bacterial Agents; China; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Feces; Swine

Topics: Adolescent; Adult; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Female; Hospitals, University; Humans; Infant; Japan; Male; Microbial Sensitivity Tests; Multilocus Sequence Typing; Polymerase Chain Reaction; Sequence Analysis, DNA

Of 11 mcr-1-harboring plasmids previously identified from livestock in Korea, we performed whole plasmid sequencing on 3 plasmids and determined the genetic structure surrounding mcr-1 for all 11 plasmids. Transconjugation frequencies were measured for all mcr-1-harboring plasmids and competitive growth experiments were performed to investigate the fitness cost of each plasmid. Although they belong to different clones, the mcr-1-harboring plasmids, pEC006 and pEC019, were highly similar to the first identified mcr-1-carrying Incl2-type plasmid, pHNSHP45. Another IncX4-type plasmid, pEC111, had completely different structure from these plasmids, but was similar to pMCR1-IncX4. A nearly identical 11.3 kb mcr-1 region (nikB-ISApl1-mcr-1-pap2-topB) was shared by all mcr-1-harboring plasmids except pEC111. The transfer rate of mcr-1-harboring plasmids was highly variable (10

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Livestock; Microbial Sensitivity Tests; Plasmids; Republic of Korea; Sequence Analysis, DNA

Plasmid-encoded colistin resistance is emerging among extraintestinal pathogenic

Topics: Animals; Anti-Bacterial Agents; Antibodies, Monoclonal; Colistin; Drug Resistance, Multiple, Bacterial; Endotoxins; Escherichia coli Infections; Escherichia coli Proteins; Extraintestinal Pathogenic Escherichia coli; Female; Humans; Lipopolysaccharides; Mice; Mice, Inbred BALB C

In 2015, colistin-resistant Escherichia coli and Salmonella with the mcr-1 gene were isolated from a pig farm in Great Britain. Pigs were subsequently monitored over a ~20-month period for the occurrence of mcr-1-mediated colistin resistance and the risk of mcr-1 E. coli entering the food chain was assessed.. Pig faeces and slurry were cultured for colistin-resistant E. coli and Salmonella, tested for the mcr-1 gene by PCR and selected isolates were further analysed. Seventy-eight per cent of faecal samples (n = 275) from pigs yielded mcr-1 E. coli after selective culture, but in positive samples only 0·2-1·3% of the total E. coli carried mcr-1. Twenty months after the initial sampling, faecal samples (n = 59) were negative for E. coli carrying mcr-1.. The risk to public health from porcine E. coli carrying mcr-1 was assessed as very low. Twenty months after cessation of colistin use, E. coli carrying mcr-1 was not detected in pig faeces on a farm where it was previously present.. The results suggest that cessation of colistin use may help over time to reduce or possibly eliminate mcr-1 E. coli on pig farms where it occurs.

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Feces; Longitudinal Studies; Swine

Antibiotic resistance associated with the mcr-1 gene of Gram-negative bacteria, which confers resistance to drugs of last resort and has the potential to spread via plasmids, is one of the most pressing issues facing global health today. Point-of-care testing for the mcr-1 gene is needed to aid in the identification of colistin resistance in the field and to control its horizontal transmission. Here, we report the successful development of an enzyme-free homogenous electrochemical strategy for sensitive detection of the antibiotic resistance gene mcr-1 using the hybridization chain reaction and mcr-1-specific toehold probe. The long double-stranded DNA polymer produced using this strategy could be detected by assessing the diffusion of methylene blue towards the surface of a screen-printed gold electrode. Under optimized conditions, a linear relationship was observed between the variation of peak current and the natural logarithm of the mcr-1 gene concentration in the range of 1 nM to 1 μM with a detection limit of 0.78 nM (S/N = 3). This enzyme-free, isothermal platform is a rapid, portable, disposable, and sensitive method for detection of plasmid-mediated colistin resistance.

Topics: Anti-Bacterial Agents; Biosensing Techniques; Colistin; Drug Resistance, Bacterial; Electrochemical Techniques; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Genes, Bacterial; Humans; Plasmids

We hereby report the first characterization of mcr-3 gene from healthy animals in South Korea. Out of 636 E. coli isolates, collected between 2014- 2017, nine colistin resistant isolates were screened for the presence of mcr-1 and mcr-3 genes. Nine (1.4%) isolates had shown resistance for colistin and among them three and two isolates were mcr-1 harboring and mcr-3 harboring strains, respectively. All the colistin-resistant isolates were multidrug-resistant. mcr-1 and mcr-3 genes were confirmed to be transferred to a recipient E. coli J53 AZ

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Livestock; Microbial Sensitivity Tests; Plasmids; Poultry; Republic of Korea

Camels (Camelus dromedarius) are known to harbor multidrug resistant Gram-negative bacteria and to be involved in the transmission of various microorganisms to humans. Data on the occurrence of colistin resistant Escherichia coli as well as mobilized colistin resistance (mcr) genes in camels are lacking. We investigated the presence of colistin resistance and mcr (1-2) genes in E. coli from the feces of camels in Tunisia. Presumptive E. coli isolates from camel-calves in southern Tunisia were qualitatively screened for growth on Mueller-Hinton agar supplemented with 2 mg/L of colistin. The minimal inhibitory concentration of colistin was determined for isolates growing on this medium. All isolates were screened for the presence of the mcr-1 and mcr-2 genes by polymerase chain reaction without detecting any of these genes. However, one isolate was confirmed resistant to colistin and further testing of this isolate revealed it to be Enterobacter cloacae. Our study demonstrated absence of colistin resistance and of the mcr-1 and mcr-2 genes in E. coli isolated from camel feces in southern Tunisia. Thus, there is no evidence that camels represent a major source of mcr genes contamination for the local population or for tourists visiting southern Tunisia.

Topics: Animals; Anti-Bacterial Agents; Camelus; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Feces; Membrane Proteins; Tunisia

To evaluate the prevalence of clinical mcr-1-positive Escherichia coli and Klebsiella pneumoniae and characterize the antimicrobial resistance profiles of mcr-1-positive E. coli and mcr-1-negative E. coli in China.. A total of 6264 clinical E. coli (n = 3854) and K. pneumoniae (n = 2410) were collected from hospitalized patients from 18 to 20 hospitals as part of the China Antimicrobial Resistance Surveillance Trial (CARST) between January 2007 and June 2016. PCR was used to screen for the mcr-1 gene among all isolates. Antibiotic susceptibility testing was performed using the broth microdilution method. mcr-1-positive pathogens were then characterized by MLST and minimum spanning tree analysis using the BURST algorithm for related STs.. We examined 39 (0.62%) clinical isolates of mcr-1-positive E. coli and K. pneumoniae over a 10 year period. Resistance to antimicrobial agents was significantly more severe in mcr-1-positive isolates than mcr-1-negative isolates, particularly piperacillin (P = 0.008), amikacin (P < 0.0001), nitrofurantoin (P < 0.004) and fosfomycin (P < 0.0001). Among mcr-1-carrying isolates, ESBL production was as high as 84.6% (33 of 39) and 92.3% (36 of 39) of them displayed an MDR phenotype. STs suggested ubiquitous dissemination of mcr-1-carrying pathogens.. mcr-1-carrying E. coli and K. pneumoniae displayed a lower prevalence and abundant phylogenetic diversity in mainland China. mcr-1-positive E. coli showed significant differences in antimicrobial resistance profiles compared with mcr-1-negative E. coli strains, suggesting physicians may consider prescribing different antibiotics when faced with infections caused by mcr-1-positive pathogens.

Topics: Anti-Bacterial Agents; Bacterial Proteins; Bacterial Typing Techniques; China; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Female; Humans; Klebsiella Infections; Klebsiella pneumoniae; Male; Microbial Sensitivity Tests; Multilocus Sequence Typing; Phylogeny; Retrospective Studies

Topics: Adult; Aged; Anti-Bacterial Agents; Bacteriological Techniques; Brazil; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Female; Genotype; Hospitals, Teaching; Humans; Immunocompromised Host; Inpatients; Male; Middle Aged; Sequence Analysis, DNA; Serogroup; Whole Genome Sequencing

The recent emergence of a transferable colistin resistance mechanism, MCR-1, has gained global attention because of its threat to clinical treatment of infections caused by multidrug-resistant Gram-negative bacteria. However, the possible transmission route of

Topics: Anti-Bacterial Agents; China; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Feces; Gene Transfer, Horizontal; Genetic Variation; Hospitals; Humans; Molecular Typing; Plasmids

The mcr-1 gene encodes a phosphoethanolamine transferase, which confers resistance to colistin by transferring phosphoethanolamine to lipid A. This study describes the emergence of a colistin- and carbapenem-resistant clinical isolate of Escherichia coli harbouring mcr-1 and blaNDM-5 genes, located on 90 and 150 Kb plasmids, respectively. The isolate belonged to ST132. This is the first report of a clinical isolate in Japan co-harbouring mcr-1 and blaNDM-5.

Topics: Anti-Bacterial Agents; beta-Lactamases; Carbapenems; Child, Preschool; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Genotype; Humans; Japan; Male; Molecular Typing; Plasmids

Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; China; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Female; Hospitals, Teaching; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Prevalence

Colistin has been used for therapy of carbapenem-resistant Gram-negative infections in Thailand, especially carbapenem-resistant. A prospective observational study was performed in adult hospitalized patients at Siriraj Hospital who received colistin for treatment of infections during December 2016 and November 2017. The surveillance culture samples were collected from the stool and the site of infection of each patient who received colistin at the study enrollment, days 3 and 7 after the study enrollment, and once a week thereafter for determination of CoR EC and CoR KP. CoR EC and CoR KP were also tested for a presence of mcr-1 gene.. One hundred thirty-nine patients were included. Overall prevalence of CoR EC or CoR KP colonization was 47.5% among 139 subjects. Prevalence of CoR EC or CoR KP colonization was 17.3% of subjects at study enrollment, and 30.2% after study enrollment. Use of fluoroquinolones, aminoglycosides, and colistin was found to be significantly associated with CoR EC or CoR KP colonization. The mcr-1 gene was detected in 13.0% of CoR EC or CoR KP isolates, and in 27.3% of subjects with CoR EC or CoR KP colonization. CoR EC or CoR KP colonization persisted in 65.2% of the subjects at the end of the study. Five patients with CoR KP infections received combination antibiotics and they were alive at hospital discharge.. Prevalence of CoR EC or CoR KP colonization in hospitalized patients receiving colistin was high and it was associated with the use of colistin. Therefore, patients who receive colistin are at risk of developing CoR EC or CoR KP colonization and infection.

Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Bacterial Proteins; Colistin; Communicable Diseases, Emerging; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Feces; Female; Hospitalization; Humans; Klebsiella Infections; Klebsiella pneumoniae; Male; Microbial Sensitivity Tests; Middle Aged; Prospective Studies; Thailand

MCR-1-positve Escherichia coli (MCRPEC) have been reported in humans worldwide; however, thus far, their prevalence is low and potential sources for human mcr-1 carriage have not yet been identified. Here, we analyse a nationwide epidemiological dataset on MCRPEC in humans throughout China and assess the factors associated with MCRPEC carriage using natural and national anthropogenic data. We identified 774 non-duplicate MCRPEC isolates from 774 stool samples collected from 5,159 healthy individuals in 30 provinces and municipalities in 2016, with a prevalence of MCRPEC ranging from 3.7 to 32.7% (average: 15.0%)-substantially higher than previously reported. MCRPEC carriage was associated with provincial regions, the production of sheep and freshwater aquaculture, annual consumption of total meat, pork and mutton, and daily intake of aquaculture products. MCRPEC was significantly more prevalent in provinces with higher aquaculture industries. Whole-genome sequencing analysis revealed that the MCRPEC isolates were clustered into four distinct lineages, two of which were dominant and harboured most of the MCRPEC isolates. The high prevalence of MCRPEC in the community poses a substantial risk for colistin usage in clinical practice and suggests the need for intestinal screening of mcr-1 carriers in intensive care units in Chinese hospitals. Furthermore, our data suggest that aquaculture is a significant reservoir of mcr-1.

Topics: Animals; Anti-Bacterial Agents; Chickens; China; Colistin; Cross-Sectional Studies; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Feces; Genome, Bacterial; Humans; Microbial Sensitivity Tests; Whole Genome Sequencing

Topics: Anti-Bacterial Agents; beta-Lactamases; Carbapenems; China; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Plasmids

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Enterotoxigenic Escherichia coli; Escherichia coli Infections; Gene Transfer, Horizontal; Genes, Bacterial; Genotype; Interspersed Repetitive Sequences; Microbial Sensitivity Tests; Multilocus Sequence Typing; Plasmids; Shiga-Toxigenic Escherichia coli; Swine; Swine Diseases; Virulence Factors

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Lebanon; Poultry

Resistance to last-line polymyxins mediated by the plasmid-borne mobile colistin resistance gene (

Topics: Anti-Bacterial Agents; beta-Lactamases; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Male; Middle Aged; Phylogeny; Plasmids

Colistin is one of the last-resort antibiotics for the treatment of multidrug-resistant infections in humans, but transmissible colistin-resistance genes have emerged in bacteria from animals. The rapid and sensitive detection among animals of colonization with bacteria carrying these genes is critical in helping to control further spread. Here we describe a method for broth enrichment of colistin-resistant. La colistine est un des antibiotiques de dernier recours pour le traitement d’infections causées par des bactéries multi-résistantes chez l’humain, mais des gènes transmissibles de résistance à la colistine ont émergé chez des bactéries provenant d’animaux. La détection rapide et sensible parmi les animaux de la colonisation par ces bactéries porteuses de ces gènes est critique afin d’aider à limiter la propagation. Nous décrivons ici une méthode pour un enrichissement en bouillon des souches de

Topics: Animals; Anti-Bacterial Agents; Chickens; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Feces; Membrane Proteins; Swine

Colistin-resistant Escherichia coli are isolated from pigs suffering from post-weaning diarrhea (PWD). This study was designed to develop an experimental model of PWD using mcr-1-carrying shiga toxin-producing E. coli (STEC) or enterotoxigenic E. coli (ETEC), for the future evaluation of control measures. Three groups of eight piglets, kept in high biosecurity units, were orally inoculated with mcr-1-positive STEC or ETEC, and one unchallenged group was used as a control. Clinical signs were recorded. Regularly-collected fecal samples and samples obtained from the digestive tract of animals sacrificed one month after inoculation were cultured in selective media and isolates were characterized. Blood samples were used to genotype the polymorphisms of the pigs' intestinal receptors for F4 and F18 E. coli adhesins. Diarrhea was more frequent and more fecal samples contained the inoculated strain in the group inoculated with the O149-F4 ETEC strain than with the O141-F18 or O139-F18 STEC strains. However, fewer positive samples were obtained from the two pigs with the F4 resistant genotype. The three inoculated strains could be re-isolated up to the end of the experiment. Excretion peaked on the first week after inoculation with the O149-F4 ETEC strain, and later for the other two. An mcr-1 gene transfer to other commensal isolates was observed only for O139-F18 STEC, while the loss of mcr-1 from the inoculated strain occurred in all groups. The O149-F4 ETEC challenge may be used to evaluate alternative solutions to combat PWD caused by colistin-resistant E. coli in pigs.

Topics: Animals; Antibodies, Bacterial; Colistin; Diarrhea; Disease Models, Animal; Drug Resistance, Bacterial; Enterotoxigenic Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Feces; Genotype; Swine; Swine Diseases; Weaning

The emergence of mobile colistin resistance genes (mcr) is yet another challenge in the fight against antimicrobial resistance, with reports proving the dissemination of these genes in different countries and different environments being of great concern. In the present study, we describe the recovery of three E. coli strains with mcr-1 gene in IncHI2 plasmids from intestinal content of necropsied meat rabbits reared in two intensive production systems in Portugal. Our findings are worrisome, given the high level of dependence on the usage of antibiotics in rabbit rearing and call for the development and implementation of an active surveillance system in this species.

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Farms; Gene Transfer, Horizontal; Livestock; Microbial Sensitivity Tests; Plasmids; Rabbits

To characterize extended-spectrum β-lactamase-producing Escherichia coli harboring the colistin resistance gene mcr-1 from human fecal samples collected in 2012 in a rural area of Shandong province, PR China.. Whole-genome sequencing and antimicrobial susceptibility testing was performed on 25 mcr-1-positive isolates to determine carriage of antibiotic resistance and virulence genes, diversity and antibiotic resistance profiles.. The isolates were highly genetically diverse and carried a large variety of different antibiotic resistance genes. The multidrug-resistance rate was high (96%). Virulence genes associated with intestinal pathogenic E. coli were carried by 32% of the isolates.. Further monitoring of the epidemiological situation is necessary to ensure a preparedness for potential emergence of novel, difficult-to-treat strains and awareness of available treatment options.

Topics: Anti-Bacterial Agents; Bacterial Toxins; beta-Lactamases; China; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Feces; Humans; Microbial Sensitivity Tests; Molecular Epidemiology; Phylogeny; Plasmids; Rural Population; Virulence; Whole Genome Sequencing

Recently it was described the plasmidial gene mcr-1 associated with colistin resistance. We screened by PCR and sequencing for gene mcr-1 in thirteen clinical isolates resistant to colistin. We observed amplification in one E. coli. To our knowledge, this is the first report of the presence of mcr-1 gene in Chile.

Topics: Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Microbial Sensitivity Tests

Colistin and carbapenem are two lines of last-resort antibiotics against lethal infections caused by MDR Gram-negative pathogens. The emergence of carbapenemase-positive Escherichia coli with colistin resistance poses a serious threat to public health worldwide. Here we report, for the first time (to the best of our knowledge), a novel combination therapy used for the treatment of E. coli co-producing MCR-1 and NDM-5.. The MICs of colistin were determined alone and with 1-4 mg/L amikacin. A 7-by-4 time-kill array of colistin (0, 0.5, 1, 2, 4, 8 and 16 mg/L) and amikacin (0, 1, 2 and 4 mg/L) over 48 h was designed to characterize the in vitro activity of these agents alone and in combination against each E. coli isolate at an inoculum of 10 6 and 10 8 cfu/mL. The sigmoid E max model was utilized for better delineation of the concentration-effect relationship of each combination. In vivo effectiveness was investigated using a mouse model (combination therapy with intraperitoneal colistin plus amikacin compared with monotherapy).. For colistin-resistant isolates, the addition of amikacin demonstrated augmented susceptibility, reducing colistin MICs below the current susceptibility breakpoint. A concentration-dependent decrease in the EC 50 values of colistin was observed for all study isolates in the presence of increasing amikacin concentrations. Further in vivo treatment experiments demonstrated that this combination could achieve 1.5-2.8 log 10 killing after 24 h of therapy, while monotherapy was unable to achieve such a killing effect.. The combination of colistin and amikacin may be a promising therapeutic option for the treatment of lethal infections caused by NDM-5-bearing MCR-1-positive superbugs.

Topics: Amikacin; Animals; Anti-Bacterial Agents; beta-Lactamases; Colistin; Drug Resistance, Multiple, Bacterial; Drug Synergism; Drug Therapy, Combination; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Mice; Microbial Sensitivity Tests

To evaluate whether acquired resistance to cationic antimicrobial peptide (CAMP) group molecules, being normal components of the human immune system, may select co-resistance to antibiotic peptides such as polymyxins, considering they share the same mechanism of action. We aimed to evaluate strains producing the recently identified plasmid-encoded polymyxin resistance determinant MCR-1, which is a phosphoethanolamine transferase that modifies the lipopolysaccharide structure of Gram-negative bacteria.. In vitro susceptibility studies were performed using human CAMPs, namely cathelicidin LL-37, α-defensin 5 (HD5), and β-defensin 3 (HDB3), towards MCR-1-producing and colistin-resistant Escherichia coli or Klebsiella pneumoniae.. Cross-resistance to CAMPs and colistin mediated by MCR-1 or chromosomal mechanisms was neither observed in E. coli nor in K. pneumoniae.. Future therapeutic development of human CAMPs is not likely to be impeded by the spread of MCR-1 plasmid-mediated resistance to polymyxins, at least in E. coli.

Topics: Antimicrobial Cationic Peptides; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Klebsiella Infections; Klebsiella pneumoniae; Polymyxins

Topics: Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Inpatients; Multilocus Sequence Typing; Plasmids

The spread of

Topics: Adult; Anti-Bacterial Agents; Bacterial Proteins; beta-Lactamases; Carbapenem-Resistant Enterobacteriaceae; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; France; Genome, Bacterial; Humans; Klebsiella Infections; Klebsiella pneumoniae; Male; Plasmids; Portugal

We identified discrete importation events of the mcr-1 gene on incompatibility group IncI2 plasmids in Escherichia coli isolated from patients in New South Wales, Australia, in 2011 and 2013. mcr-1 is present in a small minority of colistin-resistant Enterobacteriaceae and appears not to be established locally.

Topics: Anti-Bacterial Agents; Australia; Base Sequence; Binding Sites; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Food Microbiology; History, 21st Century; Humans; Microbial Sensitivity Tests; Plasmids; Promoter Regions, Genetic; Ribosomes

Although coexistence of

Topics: Adult; Animals; Anti-Bacterial Agents; beta-Lactamases; Colistin; Conjugation, Genetic; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Enterobacteriaceae; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Female; Gene Expression Regulation, Bacterial; Genes, Bacterial; Genes, MDR; Humans; Kinetics; Male; Mice; Mice, Inbred BALB C; Microbial Sensitivity Tests; Multilocus Sequence Typing; Plasmids; Sequence Analysis; Virulence; Whole Genome Sequencing

Plasmid-mediated resistance to carbapenems and colistin in Enterobacteriaceae represents an emerging public health threat. Although animals have been identified as a relevant source of multidrug-resistant (MDR) bacteria, there are only a few reports on the presence of carbapenemases in animal isolates. In this study, 7850 faecal Escherichia coli isolates obtained from 2160 pigs were screened for carbapenem non-susceptibility using Mueller-Hinton agar supplemented with meropenem. Eleven isolates showed growth on meropenem-containing agar but only two proved positive by PCR for a carbapenemase gene, namely bla

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Carbapenems; Colistin; Conjugation, Genetic; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Farms; Gene Transfer, Horizontal; Italy; Multilocus Sequence Typing; Plasmids; Swine

Polymyxin is a cationic polypeptide antibiotic that can disrupt bacterial cell membrane by interacting with its lipopolysaccharide molecules and is used as a last resort drug against lethal infections by the carbapenem-resistant superbugs (like NDM-1). However, global discovery of the MCR-1 colistin resistance dramatically challenges the newly renewed interest in colistin for clinical use.. The mcr-1-harboring plasmids were acquired from swine and human Escherichia coli isolated in China, from 2015 to 2016, and subjected to Illumina PacBio RSII and Hi-Seq2000 for full genome sequencing. PCR was applied to close the gap of the assembled contigs. Ori-Finder was employed to predict the replication origin (oriC) in plasmids. The phenotype of MCR-1-producing isolates was evaluated on the LBA plates with various level of colistin. Genetic deletion was used to test the requirement of the initial "ATG" codon for the MCR-1 function.. Here, we report full genomes of over 10 mcr-1-harboring plasmids with diversified replication incompatibilities. A novel hybrid IncI2/IncFIB plasmid pGD17-2 was discovered and characterized from a swine isolate with colistin resistance. Intriguingly, co-occurrence of two unique mcr-1-bearing plasmids (pGD65-3, IncI2, and pGD65-5, IncX4) was detected in a single isolate GD65, which might accelerate dissemination of the mcr-1 under environmental selection pressure. Genetic analyses of these plasmids mapped mobile elements in the context of antibiotic resistance and determined two insertion sequences (ISEcp1 and ISApl1) that are responsible for the mobilization of mcr-1. Gene deletion also proved that the first ATG codon is redundant in the mcr-1 gene.. Collectively, our results extend landscapes of the diversified mcr-1-bearing plasmid reservoirs.

Topics: Animals; Anti-Bacterial Agents; Carbapenems; China; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Fenoterol; Gene Deletion; Humans; Interspersed Repetitive Sequences; Plasmids; Replication Origin; Sequence Analysis, DNA; Swine

The aim of this study was to investigate the presence of plasmid-mediated colistin resistance genes in Escherichia coli from pigs affected by post-weaning diarrhoea (PWD).. DNA samples collected from 51 E. coli isolates from Italian pigs affected by PWD in 2015-2016 were studied. Isolates were classified as presumptively resistant to colistin by routine susceptibility testing and were investigated for the presence of the mcr-1 gene of plasmid origin by PCR. E. coli isolates testing negative for mcr-1 were analysed for the presence of a novel plasmid-mediated gene, mcr-2. Isolates were characterised for fimbrial [F4 (k88), F5 (k99), F6 (987P), F18 and F41] and toxin (LT, STa, STb and Stx2e) determinants by PCR as well as for the occurrence of haemolysis by phenotypic observation. Susceptibility to apramycin, cefquinome, enrofloxacin, florfenicol, gentamicin, tetracycline and trimethoprim/sulfamethoxazole (SXT) was also determined by disk diffusion.. Most of the isolates showed the presence of at least one virulence factor, confirming their pathogenic potential. The presence of mcr-1 was shown in 37 (72.5%) of the 51 isolates. All of the mcr-1-negative isolates tested negative for the mcr-2 gene. Moreover, 80.4% of the isolates were resistant to apramycin, 9.8% to cefquinome, 54.9% to enrofloxacin, 52.9% to florfenicol, 76.5% to gentamicin, 96.1% to tetracycline and 78.4% to SXT.. This is the first report documenting the presence of the mcr-1 gene in pathogenic E. coli isolated from pigs affected by PWD in Italy.

Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; Bacterial Toxins; Colistin; Diarrhea; Disk Diffusion Antimicrobial Tests; DNA, Bacterial; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Fimbriae, Bacterial; Genes, Bacterial; Hemolysis; Italy; Swine; Swine Diseases; Virulence Factors; Weaning

The mcr-1 was first detected on a plasmid in colistin-resistant Escherichia coli from livestock and patients in China. We described here the emergence of colistin-resistant E. coli clinical isolates harboring mcr-1 on the chromosomes in Vietnam. To our knowledge, this is the first report of hospital-acquired E. coli isolates harboring mcr-1 in a medical setting in Vietnam.

Topics: Animals; Anti-Bacterial Agents; China; Colistin; Cross Infection; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Livestock; Vietnam

Escherichia coli Ec36 was recovered from a patient in Portugal after treatment with meropenem and colistin. Besides an IncF plasmid with Tn1441d-bla

Topics: Anti-Bacterial Agents; beta-Lactamases; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Genotype; Humans; Meropenem; Microbial Sensitivity Tests; Portugal; Serogroup; Thienamycins

Topics: Animals; Anti-Bacterial Agents; Chromosomes, Bacterial; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Microbial Sensitivity Tests; Plasmids; Polymyxins

The mcr-1 is a gene encoding a phosphoethanolamine transferase, which confers resistance to colistin by transferring phosphoethanolamine to lipid A. We describe here the emergence of a colistin-resistant Escherichia coli clinical isolate harboring plasmid-mediated mcr-1 in Japan. The isolate belonged to ST5702 and is suspected to come from livestock and transmitted to human. This is the first report of a clinical isolate harboring mcr-1 in Japan.

Topics: Adolescent; Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Feces; Humans; Japan; Livestock; Male; Plasmids

The plasmid-mediated colistin resistance gene, mcr-1, was identified for the first time from a hospitalized patient in South Korea. The mcr-1 gene was successfully transferred to E. coli J53 recipient and conferred resistance to colistin in the recipient. The mcr-1-harboring plasmid possessed a typical IncI2 group and did not have the mcr-1-associated ISApl1 element.

Topics: Animals; Anti-Bacterial Agents; Base Sequence; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Genome, Bacterial; Humans; Livestock; Microbial Sensitivity Tests; Plasmids; Republic of Korea; Sequence Analysis, DNA

A novel variant of the plasmid-borne colistin resistance gene mcr-3 was detected on an IncHI2 plasmid in an ST131 CTX-M-55-producing Escherichia coli isolate from a Danish patient with bloodstream infection in 2014. The discovery of novel plasmid-borne genes conferring resistance to colistin is of special interest since colistin has reemerged as an important drug in the treatment of infections with multidrug-resistant Gram-negative bacteria.

Topics: Anti-Bacterial Agents; Colistin; Denmark; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Genotype; Humans; Plasmids

Colistin resistance genes mcr-3 and mcr-1 have been detected in an Escherichia coli isolate from cattle faeces in a Spanish slaughterhouse in 2015. The sequences of both genes hybridised to same plasmid band of ca 250 kb, although colistin resistance was non-mobilisable. The isolate was producing extended-spectrum beta-lactamases and belonged to serotype O9:H10 and sequence type ST533. Here we report an mcr-3 gene detected in Europe following earlier reports from Asia and the United States.

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Cattle; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Feces; Microbial Sensitivity Tests; Molecular Typing; Peptides; Polymerase Chain Reaction; Sentinel Surveillance

We characterized the genetic environment of

Topics: Animals; Anti-Bacterial Agents; Chickens; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Food Microbiology; Humans; Plasmids; Switzerland

A colistin- and carbapenem-resistant

Topics: Amino Acid Substitution; Anti-Bacterial Agents; beta-Lactamases; Colistin; DNA Transposable Elements; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Gene Expression Regulation, Bacterial; Humans; Microbial Sensitivity Tests; Mutation; Plasmids; Protein Isoforms

The increasing incidence of intestinal colonization with extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae and Gram negative organisms that has been observed in food animals such as poultry, cattle and pigs, are suggestive that animals, food and environment are potential sources of ESBL-producing bacteria. Hence, the aim of this study was to characterized commensal E. coli obtained from healthy broiler and turkey flocks at slaughter for the presence of penicillinases-, ESBL-, extended-spectrum AmpC (ESAC)-, plasmid-mediated quinolone resistance- and MCR-encoding genes. Study of clonal relatedness showed genetic diversity among CTX-M-type, SHV-12 and TEM-52 producing isolates with human isolates of the same type, was also assessed. We detected that eleven (5.4%, 11/202) and forty-five (2.2%, 45/185) E. coli isolates from broilers and turkeys, respectively, carried bla

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Cephalosporins; Chickens; Colistin; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Food Contamination; Plasmids; Portugal; Poultry Diseases; Turkeys

Topics: Animals; Chickens; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Food Microbiology; Microbial Sensitivity Tests; Pakistan; Plasmids; Poultry Diseases

The mcr-1 (mobile colistin resistance 1) gene, which encodes phosphoethanolamine transferase, has been recently identified as a source of acquired resistance to polymyxins in Escherichia coli. Using the SuperPolymyxin selective medium, we prospectively screened 100 pigs at 2 farms in Portugal for polymyxin-resistant Enterobacteriaceae and recovered 98 plasmid-mediated MCR-1-producing isolates. Most isolates corresponded to nonclonally related E. coli belonging to many sequence types; we also found 2 Klebsiella pneumoniae sequence types. The mcr-1 gene was carried on IncHI2 or IncP plasmid backbones. Our finding of a high rate of MCR-1 producers on 2 pig farms in Portugal highlights the diffusion of that colistin-resistance determinant at the farm level. The fact that the pigs received colistin as metaphylaxis in their feed during the 6 weeks before sampling suggests selective pressure.

Topics: Animals; Anti-Bacterial Agents; Colistin; Conjugation, Genetic; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Farms; Gene Dosage; Gene Expression; Gene Transfer, Horizontal; Klebsiella Infections; Klebsiella pneumoniae; Membrane Proteins; Plasmids; Portugal; Swine

We describe an IncX4 pHC891/16mcr plasmid carrying mcr-1 in a colistin-resistant and carbapenem-susceptible E. coli isolate (HC891/16), ST156, which caused a blood infection in a Brazilian patient with gallbladder adenocarcinoma.. Strain HC891/16 was subjected to whole genome sequencing using the MiSeq Platform (Illumina, Inc., USA). Assembly was performed using Mira and ABACAS.. The isolates showed resistance only to ciprofloxacin, ampicillin and cefoxitin, and whole-genome sequencing revealed the presence of aac(6')Ib-cr and blaTEM1.. Our findings warn of the possible silent dissemination of colistin resistance by carbapenem-susceptible mcr-1 producers, as colistin susceptibility is commonly tested only among carbapenem-resistant isolates.

Topics: Aged; Anti-Bacterial Agents; Bacteremia; Brazil; Carbapenems; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Female; Humans; Microbial Sensitivity Tests; Plasmids

MCR-1 is a lipid A modifying enzyme that confers resistance to the antibiotic colistin. Here, we analyse the impact of MCR-1 expression on E. coli morphology, fitness, competitiveness, immune stimulation and virulence. Increased expression of mcr-1 results in decreased growth rate, cell viability, competitive ability and significant degradation in cell membrane and cytoplasmic structures, compared to expression of catalytically inactive MCR-1 (E246A) or MCR-1 soluble component. Lipopolysaccharide (LPS) extracted from mcr-1 strains induces lower production of IL-6 and TNF, when compared to control LPS. Compared to their parent strains, high-level colistin resistance mutants (HLCRMs) show reduced fitness (relative fitness is 0.41-0.78) and highly attenuated virulence in a Galleria mellonella infection model. Furthermore, HLCRMs are more susceptible to most antibiotics than their respective parent strains. Our results show that the bacterium is challenged to find a delicate equilibrium between expression of MCR-1-mediated colistin resistance and minimalizing toxicity and thus ensuring cell survival.

Topics: Animals; Anti-Bacterial Agents; Cell Membrane; Colistin; Disease Models, Animal; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Larva; Microbial Sensitivity Tests; Moths

Topics: Acute Disease; Anti-Bacterial Agents; Colistin; Diarrhea; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans

Reports of livestock infections with extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-E) are increasing. Based on interviews conducted over a 6-month period, we found that veterinarians in the Vietnamese province of Thai Binh prefer to prescribe colistin-based drugs (CBD) in chicken farms. We aimed to clarify whether CBD use selects for strains of colistin-resistant ESBL-E. With the cooperation of seven local households, we detected ESBL-E in chickens' feces after treating chickens with CBD. Phylogenetic groupings and the presence of CTX-M/AmpC genes were determined, and the multi-antibiotic susceptibility of isolates was analyzed. Our results showed that ESBL-E presented in seven chickens' feces from two households. Seventy-two percent of ESBL-E isolates harbored CTX-M9 and the phylogenetic group A; the colistin minimum inhibitory concentration (MIC) of all isolated ESBL-E ranged from 0.064 to 1 μg mL

Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; beta-Lactamases; Chickens; Colistin; Escherichia coli; Escherichia coli Infections; Farms; Feces; Microbial Sensitivity Tests; Phylogeny; Poultry Diseases; Thailand; Vietnam

We screened mcr-1 and mcr-2 genes in 9,306 Escherichia coli strains isolated from healthy animals in the Japanese Veterinary Antimicrobial Resistance Monitoring (JVARM) system. mcr-1 was detected in 39 strains (5, 20, and 14 strains isolated from cattle, swine, and broilers, respectively), whereas mcr-2 was not detected. mcr-2 was also not detected with the investigation sequence homology search against our curated GenEpid-J database.

Topics: Animal Husbandry; Animals; Anti-Bacterial Agents; Cattle; Chickens; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Gene Expression; Japan; Meat; Poultry Diseases; Prevalence; Protein Isoforms; Swine; Swine Diseases

We reported a case of Escherichia coli with colistin resistance and an extensively drug-resistant phenotype. Molecular analysis revealed that the isolate carried mcr-1 and multiple β-lactamase genes includingbla

Topics: Anti-Bacterial Agents; beta-Lactamases; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Genes, Bacterial; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Multiplex Polymerase Chain Reaction; Plasmids; Sequence Analysis, DNA; Thailand

Topics: Animals; Anti-Bacterial Agents; Colistin; Disease Transmission, Infectious; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Reptiles; Risk Factors

Topics: Adult; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Genotype; Humans; Male; Microbial Sensitivity Tests; Molecular Typing; Peritonitis; Sequence Analysis, DNA

Sixteen different sequence types (STs) of

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Carbapenems; China; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Gene Expression; Gene Transfer, Horizontal; Genetic Fitness; Genotype; Plasmids; Swine; Swine Diseases

Topics: Adult; Anti-Bacterial Agents; beta-Lactamases; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Male; Microbial Sensitivity Tests; New Caledonia

The PCR amplification of ETEC virulence genes showed that nearly 100% of pigs excreted genes encoding for STa and STb toxins in the feces before the challenge. These genes, in the absence of the gene encoding F4, were considered as a marker for F4-negative ETEC. One day after ETEC: F4 oral challenge pigs in the two challenged groups excreted the genes encoding LT and F4 in the feces. These genes were considered as a marker for F4-positive ETEC. However, the gene encoding F18 was not detected in any fecal samples of the 4 groups throughout the experiment. After only 3 days of successive oral treatment with CS, a significant reduction in both the F4-positive and negative ETEC populations was observed in the challenged treated group compared to the challenged untreated group (p < 0.0001).. Our study is among the first to report that under controlled farming conditions, oral CS treatment had a significant effect on both fecal F4-positive and F4-negative ETEC in pigs. However, CS clinical efficiency was correlated with non-detection of F4-positive ETEC in the feces. Furthermore the fecal presence of F4-negative ETEC was not associated with clinical symptoms of post-weaning diarrhea in pigs.

Topics: Animals; Animals, Newborn; Colistin; Diarrhea; Enterotoxigenic Escherichia coli; Enterotoxins; Escherichia coli Infections; Escherichia coli Proteins; Feces; Genes, Bacterial; Sus scrofa; Swine; Swine Diseases; Virulence; Weaning

Topics: Anti-Bacterial Agents; Bacteriophage P1; Cephalosporins; China; Colistin; Conjugation, Genetic; DNA Transposable Elements; Drug Resistance, Bacterial; Enteropathogenic Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Fosfomycin; Humans; Lysogeny; Male; Plasmids; Sequence Analysis, DNA

Pigs have been the focus of the worldwide spread of colistin resistance. However, there is little information on the transmission of mcr-1 -containing bacteria into the environment of pig farms. We therefore rescreened environmental Escherichia coli isolates from the surrounding farm areas of three previously mcr-1 -positive swine herds in Germany.. Thirty-five mixed bacterial cultures obtained from boot swabs, flies, dog faeces and manure from three pig farms in Germany in 2011-12 were non-selectively recultivated and the presence of the mcr-1 gene was checked by real-time PCR. After separation, single E. coli colonies were subsequently isolated and the presence of mcr-1 was confirmed by PCR and sequencing. In addition, phenotypic antimicrobial resistance screening and WGS followed by phylogenetic analysis and resistance genotyping as well as plasmid typing were performed.. Seven mcr-1 -positive E. coli strains originating from environmental boot swabs, dog faeces, stable flies and manure were found. The isolates belonged to five different STs (ST10, ST1011, ST1140, ST5281 and ST342) and harboured extensive additional resistance genes. Comparative plasmid analysis predominantly located mcr-1 on IncX4 plasmids, which are strongly related to a recently described plasmid of human clinical origin (pICBEC72Hmcr).. WGS-based analysis of the environmental E. coli isolates of farm surroundings showed clear links to mcr-1 -harbouring E. coli recovered from pig production in Europe as well as from human clinical isolates worldwide, presenting another piece of the puzzle, which further complicates the rapidly evolving epidemiology of plasmid-mediated colistin-resistant E. coli strains.

Topics: Animals; Anti-Bacterial Agents; Colistin; Dogs; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Farms; Feces; Genotype; Germany; Humans; Manure; Microbial Sensitivity Tests; Phylogeny; Plasmids; Real-Time Polymerase Chain Reaction; Swine

Since colistin resistance based on the plasmid-encoded

Topics: Anti-Bacterial Agents; Austria; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Feces; Humans; Microbial Sensitivity Tests

The purpose of this study was to characterize the New Delhi metallo-beta lactamase (NDM)-7-producing Enterobacteriaceae isolated in the Arabian Peninsula.. Enterobacteriaceae identified to carry bla. Four NDM-7-producing Escherichia coli isolated in Kuwait, Oman, and the UAE, respectively, were identified. They were clonally unrelated, carried a few virulence determinants only, and belonged to clonal complexes CC10 and CC23, or ST448. They were all multi-drug resistant but remained susceptible to fosfomycin, tigecycline, and colistin. In all isolates, bla. Our findings show that IncX3 type plasmids play an important role in the spread of the currently rare NDM-7 variant in the Arabian Peninsula. This association of bla

Topics: Anti-Bacterial Agents; beta-Lactamases; Carbapenems; Clone Cells; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Fosfomycin; Gene Expression; Humans; Kuwait; Microbial Sensitivity Tests; Minocycline; Multilocus Sequence Typing; Oman; Phylogeny; Plasmids; Saudi Arabia; Tigecycline; United Arab Emirates

By 2030, the global population will be 8.5 billion, placing pressure on international poultry production, of which China is a key producer

Topics: Animals; Animals, Wild; Anti-Bacterial Agents; beta-Lactamases; Birds; Carbapenem-Resistant Enterobacteriaceae; Chickens; China; Colistin; Diptera; Dogs; Drug Resistance, Bacterial; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Genome, Bacterial; High-Throughput Nucleotide Sequencing; Microbial Sensitivity Tests; Prevalence

The detection and rapid spread of colistin-resistant

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Brazil; Chickens; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Foodborne Diseases; Humans; Meat Products; Plasmids

We investigated the consequences of colistin use in backyard chicken farms in Vietnam by examining the prevalence of mcr-1 in fecal samples from chickens and humans. Detection of mcr-1-carrying bacteria in chicken samples was associated with colistin use and detection in human samples with exposure to mcr-1-positive chickens.

Topics: Aging; Animals; Chickens; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Feces; Gene Expression Regulation, Bacterial; Humans; Microbial Sensitivity Tests; Phylogeny; Poultry Diseases; Risk Factors; Vietnam; Zoonoses

Since its initial discovery in China in 2015, the plasmid-mediated colistin resistance gene mcr-1 has been reported in Escherichia coli isolated from clinical samples, animals and meat worldwide. In this study, 706 extended-spectrum β-lactamase (ESBL)-producing E. coli from 411 persons were detected in a collection of faecal samples from 1000 rural residents in three counties in Shandong Province, China. These isolates were screened for mcr-1 and phenotypic colistin resistance. The gene was found in 3.5% of the isolates (from 4.9% of persons) from all three counties. All isolates with phenotypic colistin resistance carried mcr-1. These data indicate that commensal carriage of ESBL-producing E. coli with mcr-1 among persons in rural China was already present in 2012 and that mcr-1 was the most important colistin resistance mechanism. Interventions are necessary to minimise further dissemination of mcr-1, which would limit the future usefulness of colistin as a last-resort antibiotic.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; beta-Lactamases; Carrier State; Child; Child, Preschool; China; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Feces; Female; Humans; Infant; Infant, Newborn; Male; Microbial Sensitivity Tests; Middle Aged; Prevalence; Rural Population; Young Adult

Antimicrobial resistance associated with colistin has emerged as a significant concern worldwide threatening the use of one of the most important antimicrobials for treating human disease. Here, we examined a collection (n = 980) of Avian Pathogenic Escherichia coli (APEC) isolated from poultry with colibacillosis from the US and internationally for the presence of mcr-1 and mcr-2, genes known to encode colistin resistance. Included in the analysis was an additional set of avian fecal E. coli (AFEC) (n = 220) isolates from healthy birds for comparative analysis. The mcr-1 gene was detected in a total of 12 isolates recovered from diseased production birds from China and Egypt. No mcr genes were detected in the healthy fecal isolates. The full mcr-1 gene from positive isolates was sequenced using specifically designed primers and were compared with sequences currently described in NCBI. mcr-1 positive isolates were also assessed for phenotypic colistin resistance and extended spectrum beta lactam phenotypes and genotypes. This study has identified mcr-1 in APEC isolates dating back to at least 2010 and suggests that animal husbandry practices could result in a potential source of resistance to the human food chain in countries where application of colistin in animal health is practiced.

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Microbial Sensitivity Tests; Plasmids; Poultry Diseases

Biofilms are the preferred environment of micro-organisms on various surfaces such as catheters and heart valves, are associated with numerous difficult-to-treat and recurrent infections, and confer an extreme increase in antibiotic tolerance to most compounds. The aim of this study was to evaluate how colistin affects both the extracellular biofilm matrix and the embedded bacteria in biofilms of methicillin-resistant Staphylococcus aureus (MRSA), a species with intrinsic resistance to colistin, and colistin-susceptible Escherichia coli. Biofilms of MRSA and E. coli were treated with different concentrations of colistin. The minimum biofilm eradication concentration (MBEC) and the effectiveness of colistin at reducing the planktonic fraction were defined as the remaining viable bacteria measured as CFU/mL. In addition, biofilm-embedded cells were LIVE/DEAD-stained and were analysed by confocal laser scanning microscopy (CLSM). Quantification of the biofilm CLSM images was conducted using an open-access in-house algorithm (qBA). In contrast to MRSA, E. coli biofilms and planktonic cells were significantly reduced by colistin in a concentration-dependent manner. Nevertheless, colistin has been shown to exert a matrix-reducing effect following treatment both in laboratory strains and clinical isolates of MRSA and E. coli. Because exposure to colistin rapidly triggered the emergence of highly resistant clones, monotherapy with colistin should be applied with caution. These results suggest that colistin destabilises the biofilm matrix structure even in species with intrinsic colistin resistance, such as S. aureus, leading to the release of planktonic cells that are more susceptible to antibiotics.

Topics: Anti-Bacterial Agents; Biofilms; Colistin; Colony Count, Microbial; Escherichia coli; Escherichia coli Infections; Humans; Methicillin-Resistant Staphylococcus aureus; Microbial Viability; Microscopy, Confocal; Staining and Labeling; Staphylococcal Infections

Five strains producing extended-spectrum β-lactamases (ESBL) bacteria, identified as Escherichia coli, were isolated from children with urinary infections hospitalized at Roubaix hospital in the north of France. The DNA genotypes of these non-nosocomial isolates were determined by Random Amplified Polymorphic DNA (RAPD) method. Further, their DNA plasmids content revealed the presence of two distinct plasmids for S1, S2, S3 and one plasmid for S4 and S5. The antibacterial susceptibility of these ESBL bacteria was tested mainly against antibiotics of β-lactams family. The ESBL producing bacteria were resistant to ticarcillin and cefotaxime but the combination of these antibiotics with colistin has dropped the MIC of ticarcillin below its breakpoint (isolates S2, S3 and S4), and has almost reached the breakpoint for cefotaxime (isolate S2). Thus, kill curves analyses carried out with only isolates S1 and S2, strengthened the bactericidal activity of the combinations of colistin-ticarcillin and colistin-cefotaxime against ESBL E. coli. Indeed, reduction of 3 log10 colony count were observed after 24 h of incubation.

Topics: Anti-Bacterial Agents; beta-Lactam Resistance; beta-Lactamases; beta-Lactams; Child; Colistin; DNA, Bacterial; Drug Synergism; Escherichia coli; Escherichia coli Infections; France; Hospitals; Humans; Microbial Sensitivity Tests; Microbial Viability; Molecular Typing; Plasmids; Random Amplified Polymorphic DNA Technique; Urinary Tract Infections

Colistin resistance was investigated in 1,696 isolates collected from 2007 to 2014 within the frame of the French livestock antimicrobial resistance surveillance programme. The mcr-1 gene was detected in all commensal Escherichia coli isolates with a minimum inhibitory concentration to colistin above the 2 mg/L cut-off value (n=23). In poultry, mcr-1 prevalence was 5.9% in turkeys and 1.8% in broilers in 2014. In pigs, investigated in 2013, this prevalence did not exceed 0.5%. These findings support that mcr-1 has spread in French livestock.

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Feces; Genotype; Humans; Livestock; Meat; Microbial Sensitivity Tests; Prevalence; Swine; Turkeys

Topics: Aged, 80 and over; Anti-Bacterial Agents; Bacteremia; Ceftriaxone; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Male; Middle Aged; Plasmids

We report a high prevalence of MCR-1 and CTX-M-1-producing Escherichia coli in three Tunisian chicken farms. Chickens were imported from France or derived from French imported chicks. The same IncHI2-type plasmid reported to carry those genes in cattle in France and in a food sample in Portugal was found in Tunisian chickens of French origin. This suggests a significant impact of food animal trade on the spread of mcr-1-mediated colistin resistance in Europe.

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Chickens; Colistin; Commerce; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Food Microbiology; France; Genotype; Humans; Meat; Microbial Sensitivity Tests; Peptides; Plasmids; Prevalence; Tunisia

Topics: Anti-Bacterial Agents; Bacterial Infections; Canada; Colistin; Drug Resistance, Bacterial; Epidemiological Monitoring; Escherichia coli; Escherichia coli Infections; Humans; Morbidity

Topics: Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Egypt; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Plasmids

Topics: Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Italy; Plasmids; Retrospective Studies

Recent findings suggest that use of colistin as a last resort antibiotic is seriously threatened by the rise of a new plasmid mediated mechanism of resistance (MCR-1). This work identifies, for the first time in Southern Europe, the gene mcr-1 in nine strains from farm animals (poultry and swine) corresponding to five Escherichia coli and four Salmonella enterica, among which three belong to serovar Typhimurium and one to Rissen. The MCR-1 was found encoded by a plasmid highly mobilizable by conjugation to the E. coli J53 strain. Two E. coli strains carried two determinants, mcr-1 plus pmrA or pmrB mutations, known to confer colistin resistance.

Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Poultry Diseases; Salmonella enterica; Salmonella Infections, Animal; Salmonella typhimurium; Sequence Analysis, DNA; Spain; Swine; Swine Diseases

Colistin resistance was detected in 53 of 10,011 Escherichia coli (0.5%) by prospective phenotypic testing of consecutive clinical isolates in a single hospital in Barcelona, Spain (2012-15). The mcr-1 gene was retrospectively identified by PCR and sequencing in 15 of 50 available isolates. Each isolate had a unique PFGE pattern except for two. This clonal diversity supports the hypothesis of horizontal dissemination of the mcr-1 gene in the local study population.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Child; Colistin; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Escherichia coli; Escherichia coli Infections; Genotype; Humans; Microbial Sensitivity Tests; Middle Aged; Phenotype; Polymerase Chain Reaction; Prevalence; Prospective Studies; Spain; Young Adult

Topics: Abscess; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Epidemiological Monitoring; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Hospitals; Humans; Meat; Prevalence; Sputum; Taiwan; Urine

Antimicrobial resistance (AMR) is a global health problem, and emerging semi-intensive farming systems in Southeast Asia are major contributors to the AMR burden. We accessed 12 pig and chicken farms at key stages of production in Tien Giang Province, Vietnam, to measure antimicrobial usage and to investigate the prevalence of AMR to five critical antimicrobials (β-lactams, third-generation cephalosporins, quinolones, aminoglycosides, and polymyxins) and their corresponding molecular mechanisms among 180 Escherichia coli isolates. Overall, 94.7 mg (interquartile range [IQR], 65.3 to 151.1) and 563.6 mg (IQR, 398.9 to 943.6) of antimicrobials was used to produce 1 kg (live weight) of chicken and pig, respectively. A median of 3 (out of 8) critical antimicrobials were used on pig farms. E. coli isolates exhibited a high prevalence of resistance to ampicillin (97.8% and 94.4% for chickens and pigs, respectively), ciprofloxacin (73.3% and 21.1%), gentamicin (42.2% and 35.6%), and colistin (22.2% and 24.4%). The prevalence of a recently discovered colistin resistance gene, mcr-1, was 19 to 22% and had strong agreement with phenotypic colistin resistance. We conducted plasmid conjugation experiments with 37 mcr-1 gene-positive E. coli isolates and successfully observed transfer of the gene in 54.0% of isolates through a plasmid of approximately 63 kb, consistent with one recently identified in China. We found no significant correlation between total use of antimicrobials at the farm level and AMR. These data provide additional insight into the role of mcr-1 in colistin resistance on farms and outline the dynamics of phenotypic and genotypic AMR in semi-intensive farming systems in Vietnam.. Our study provides accurate baseline information on levels of antimicrobial use, as well as on the dynamics of phenotypic and genotypic resistance for antimicrobials of critical importance among E. coli over the different stages of production in emerging pig and poultry production systems in Vietnam. E. coli isolates showed a high prevalence of resistance (>20%) to critically important antimicrobials, such as colistin, ciprofloxacin, and gentamicin. The underlying genetic mechanisms identified for colistin (the mcr-1 gene) and quinolone (gyrA gene mutations) are likely to play a major role in AMR to those compounds. Conjugation experiments led to the identification of a 63-kb plasmid, similar to one recently identified in China, as the potential carrier of the mcr-1 gene. These results should encourage greater restrictions of such antimicrobials in Southeast Asian farming systems.

Topics: Animals; Anti-Bacterial Agents; Chickens; Colistin; Conjugation, Genetic; Drug Resistance, Bacterial; Drug Utilization; Escherichia coli; Escherichia coli Infections; Farms; Gene Transfer, Horizontal; Plasmids; Swine; Vietnam

Topics: Aged; Aged, 80 and over; Anti-Bacterial Agents; Argentina; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Female; Humans; Male; Microbial Sensitivity Tests; Middle Aged

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Egypt; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Plasmids; Sequence Analysis, DNA; Sequence Homology

Topics: Animals; Anti-Bacterial Agents; Chickens; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Microbial Sensitivity Tests; Plasmids; Poultry Diseases; South Africa

During a Brazilian multicentric antimicrobial resistance surveillance study, colistin resistance was investigated in 4,620 Enterobacteriaceae isolated from human, animal, food and environmental samples collected from 2000 to 2016. We present evidence that mcr-1-positive Escherichia coli has been emerging in South America since at least 2012, supporting a previous report on the possible acquisition of mcr-1-harbouring E. coli by European travellers visiting Latin American countries.

Topics: Animal Feed; Animals; Animals, Domestic; Anti-Bacterial Agents; Asymptomatic Infections; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Food Contamination; Food Microbiology; Global Health; Humans; South America

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Genotype; Humans; Malaysia

Enterotoxigenic Escherichia coli (ETEC: F4) associated with post-weaning diarrhea (PWD) in pigs has developed resistance against several antimicrobial families, leading to increased use of colistin sulfate (CS) for the treatment of this disease. The objective of this study was to determine the efficacy of oral CS treatment in experimental PWD due to ETEC: F4 challenge and determine the effect of this challenge on CS intestinal absorption. In this study, 96 pigs were divided into two trials based on CS dose (100 000 or 50 000 IU/kg). Fecal shedding of ETEC: F4, total E. coli, and CS-resistant E. coli, diarrhea scores, and weight changes were evaluated. Colistin sulfate plasma concentrations were determined by HPLC-MS/MS. Regardless of the dose, CS treatment resulted in a reduction of fecal ETEC: F4 and total E. coli shedding, and in diarrhea scores but only during the treatment period. However, CS treatment resulted in a slight increase in fecal shedding of CS resistant E. coli and did not prevent weight loss in challenged pigs. In addition, challenge with ETEC: F4 resulted in an increase of CS intestinal absorption. Our study is among the first to demonstrate that under controlled conditions, CS was effective in reducing fecal shedding of ETEC: F4 and total E. coli in experimental PWD. However, CS treatment was associated with a slight selection pressure on E. coli and did not prevent pig weight loss. Further studies are needed in field conditions, to better characterize CS therapeutic regimen efficacy and bacterial resistance dissemination.

Topics: Administration, Oral; Animals; Anti-Bacterial Agents; Bacterial Shedding; Colistin; Disease Models, Animal; Enterotoxigenic Escherichia coli; Escherichia coli Infections; Feces; Intestinal Absorption; Porcine Reproductive and Respiratory Syndrome; Swine

Topics: Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Feces; Genes, Bacterial; Hospitalization; Humans; Multilocus Sequence Typing; Netherlands; Plasmids; Real-Time Polymerase Chain Reaction; Tertiary Care Centers

Topics: Aged; Aged, 80 and over; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Female; Humans; Italy; Long-Term Care; Male; Symbiosis

Topics: Animals; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; History, 21st Century; Japan; Microbial Sensitivity Tests; Swine; Swine Diseases

Topics: Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Female; Genetic Variation; Humans; Livestock; Middle Aged; Plasmids; Poland; Urine

Topics: Animals; Animals, Wild; Anti-Bacterial Agents; Charadriiformes; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Feces; Humans; Plasmids

Topics: Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Genome, Bacterial; Humans; Microbial Sensitivity Tests; Norway; Plasmids; Sequence Analysis, DNA; Sequence Homology, Nucleic Acid

Topics: Animals; Anti-Bacterial Agents; Asia; beta-Lactamases; Birds; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Microbial Sensitivity Tests; Multilocus Sequence Typing; Plasmids; Polymerase Chain Reaction; Sequence Analysis, DNA

Topics: Anti-Bacterial Agents; Carbapenems; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Microbial Sensitivity Tests; Plasmids

A colistin-resistant Escherichia coli strain was recovered from a patient with a diabetic foot infection in Brazil. Whole-genome analysis revealed that the E. coli isolate belonged to the widespread sequence type (ST) 101 and harbored the mcr-1 gene on an IncX4 plasmid that was highly similar to mcr-1-bearing IncX4 plasmids that were recently identified in Enterobacteriaceae from food, animal, and human samples recovered on different continents. These results suggest that self-transmissible IncX4-type plasmids may represent promiscuous plasmids contributing to the intercontinental spread of the mcr-1 gene.

Topics: Aged; Brazil; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Male; Microbial Sensitivity Tests; Plasmids

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Cattle; Cattle Diseases; Colistin; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; France; Microbial Sensitivity Tests

Topics: Anti-Bacterial Agents; beta-Lactamases; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Plasmids

Topics: Animals; China; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Genetic Variation; Geography; Host-Pathogen Interactions; Lung; Microbiota; Plasmids; Swine; Swine Diseases

Identification of Enterobacteriaceae harbouring the plasmid-mediated transferable colistin resistance gene mcr-1 presents a new challenge to public health. The aim of this study was to characterise multidrug-resistant Shiga toxin-producing Escherichia coli (STEC) harbouring the mcr-1 gene on plasmids cultured from pigs in China. Using CHROMagar™ ECC plates combined with stx gene detection by PCR, 93 STEC were recovered from 326 faecal, 351 small intestine content and 326 colon content samples taken from healthy pigs in 2011 and 2012 in China. This study, in which ten colistin-resistant isolates with minimum inhibitory concentrations (MICs) of 8-12 mg/L were identified and found to be positive by PCR for the mcr-1 gene, is a follow-up to an earlier investigation. Plasmid profiling by S1-nuclease digestion followed by pulsed-field gel electrophoresis (PFGE) identified several high-molecular-weight plasmids and these were typed by PCR-based replicon typing (PBRT). Two of the ten isolates, namely STEC-CQ09 (O116:H11/CC23/ST88) and CQ10 (O2:H32/ST3628), were selected for further study as described in this report.

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; China; Colistin; Colon; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Escherichia coli Infections; Escherichia coli Proteins; Feces; Intestine, Small; Microbial Sensitivity Tests; Molecular Typing; Plasmids; Polymerase Chain Reaction; Shiga-Toxigenic Escherichia coli; Swine

Topics: Anti-Bacterial Agents; Canada; China; Colistin; Communicable Diseases, Imported; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Male; Middle Aged; Plasmids; Polymerase Chain Reaction; Travel

Of 150 Escherichia coli strains we cultured from specimens taken from cattle in Europe, 3 had elevated MICs against colistin. We assessed all 3 strains for the presence of the plasmid-mediated mcr-1 gene and identified 1 isolate as mcr-1-positive and co-resistant to β-lactam, florfenicol, and fluoroquinolone antimicrobial compounds.

Topics: Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; Colistin; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Europe; Female; Genes, Bacterial; Mastitis, Bovine; Microbial Sensitivity Tests

International travel is a risk factor for intestinal colonization with ESBL-producing Enterobacteriaceae (EPE). This prospective cohort study focuses on molecular features of and risk factors for travel-acquired EPE.. Rectal swabs and survey data were collected from 188 Swedes travelling to four regions of high EPE prevalence. Samples were plated onto selective agars. ESBL producers were determined using phenotypic methods. Molecular characterization regarding virulence factors and phylogenetic grouping of ESBL-producing Escherichia coli was done using PCR. Isolates were also screened for the plasmid-mediated colistin resistance gene mcr-1.. Among 175 pre-travel EPE-negative participants, 32% were positive upon return. No carbapenemase-producing Enterobacteriaceae were found, but one CTX-M-producing E. coli harboured mcr-1 (travel to Thailand). Most E. coli strains (43.1%) belonged to phylogroup A and were rarely associated with extraintestinal infections and a few (9.2%) expressed uropathogenicity pap genes. During 10-26 months of follow-up, no clinical infections were observed. Colonization rates varied by visited region: the Indian subcontinent, 49.2%; northern Africa, 44.0%; South-East Asia, 19.1%; and Turkey, 9.5%. Travellers' diarrhoea (OR 2.5, P = 0.04) or antimicrobial treatment during the trip (OR 5.9, P = 0.02) were both independent risk factors for EPE colonization.. EPE acquired during travel have seemingly low pathogenicity, possibly indicating a low risk of clinical infection. Pre-travel advice should emphasize avoiding unnecessary antibiotic treatment during travel.

Topics: Adolescent; Adult; Aged; Anti-Bacterial Agents; Bacteriological Techniques; beta-Lactamases; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Female; Humans; Male; Middle Aged; Molecular Typing; Polymerase Chain Reaction; Prospective Studies; Rectum; Sweden; Travel; Virulence Factors; Young Adult

Searching for the presence of the mcr-1 gene in colistin resistant Enterobacteriaceae in countries of the Arabian Peninsula.. Seventy-five independent, colistin resistant Enterobacteriaceae strains isolated from clinical cases in Bahrain, Kuwait, Oman, Saudi Arabia and the United Arab Emirates were tested by PCR for the mcr-1 gene. mcr-1 positive strains were genotyped, and their antibiotic susceptibility was established. The mcr-1 containing plasmids were mobilized into Escherichia coli K-12 and their sequence was determined.. Four E. coli isolates (two from Bahrain, one from Saudi Arabia and one from the United Arab Emirates) were identified carrying the mcr-1 gene on conjugative plasmids. They belonged to global multidrug resistant E. coli clones, i.e. ST648, ST224, ST68 and ST131, respectively. One strain carried the blaNDM-1 carbapenemase gene. Three strains carried mcr-1 on IncI2 type plasmids, one of them also harboring a blaCTX-M-64 gene. In the fourth strain mcr-1 was located on a 240kb IncHI2 plasmid co-harboring 13 other resistance genes.. This is the first report on the presence of the plasmid-coded mcr-1 gene in a variety of multi-resistant clinical isolates from the Arabian Peninsula indicating that several commonly used antibiotics can potentially facilitate the spread of mcr-1 carrying strains, or directly, mcr-1 containing plasmids.

Topics: Anti-Bacterial Agents; beta-Lactamases; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Humans; Kuwait; Oman; Plasmids; Saudi Arabia; United Arab Emirates

Topics: Algeria; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Plasmids

Colistin is increasingly used as an antibiotic of last resort for the treatment of carbapenem-resistant Gram-negative infections. The plasmid-borne colistin resistance gene mcr-1 was initially identified in animal and clinical samples from China and subsequently reported worldwide, including in the United States. Of particular concern is the spread of mcr-1 into carbapenem-resistant bacteria, thereby creating strains that approach pan-resistance. While several reports of mcr-1 have involved carbapenem-resistant strains, no such isolates have been described in the United States. Here, we report the isolation and identification of an Escherichia coli strain harboring both mcr-1 and carbapenemase gene blaNDM-5 from a urine sample in a patient without recent travel outside the United States. The isolate exhibited resistance to both colistin and carbapenems, but was susceptible to amikacin, aztreonam, gentamicin, nitrofurantoin, tigecycline, and trimethoprim-sulfamethoxazole. The mcr-1- and blaNDM-5-harboring plasmids were completely sequenced and shown to be highly similar to plasmids previously reported from China. The strain in this report was first isolated in August 2014, highlighting an earlier presence of mcr-1 within the United States than previously recognized.. Colistin has become the last line of defense for the treatment of infections caused by Gram-negative bacteria resistant to multiple classes of antibiotics, in particular carbapenem-resistant Enterobacteriaceae (CRE). Resistance to colistin, encoded by the plasmid-borne gene mcr-1, was first identified in animal and clinical samples from China in November 2015 and has subsequently been reported from numerous other countries. In April 2016, mcr-1 was identified in a carbapenem-susceptible Escherichia coli strain from a clinical sample in the United States, followed by a second report from a carbapenem-susceptible E. coli strain originally isolated in May 2015. We report the isolation and identification of an E. coli strain harboring both colistin (mcr-1) and carbapenem (blaNDM-5) resistance genes, originally isolated in August 2014 from urine of a patient with recurrent urinary tract infections. To our knowledge, this is the first report in the United States of a clinical bacterial isolate with both colistin and carbapenem resistance, highlighting the importance of active surveillance efforts for colistin- and carbapenem-resistant organisms.

Topics: Aged; Anti-Bacterial Agents; beta-Lactamases; Carbapenems; Colistin; DNA, Bacterial; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Male; Plasmids; Sequence Analysis, DNA; Sequence Homology; Travel; United States; Urinary Tract Infections; Urine

Colistin resistance mediated by the mcr-1 gene has been reported worldwide, but to date not from the Andean region, South America. We report the first clinical isolate of Escherichia coli harbouring the mcr-1 gene in Ecuador. The strain was isolated from peritoneal fluid from a 14-year-old male with acute appendicitis, and subjected to molecular analysis. The minimum inhibitory concentration of colistin for the strain was 8 mg/ml and it was susceptible to carbapenems but resistant to tigecycline. The strain harboured mcr-1 and bla CTX-M-55 genes and was of sequence type 609. The recognition of an apparently commensal strain of E. coli harbouring mcr-1 serves as an alert to the presence in the region of this recently described resistance mechanism to one of the last line of drugs available for the treatment of multi-resistant Gram-negative infections.

Topics: Acute Disease; Adolescent; Anti-Bacterial Agents; Appendicitis; Colistin; Drug Resistance, Bacterial; Ecuador; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Male; Microbial Sensitivity Tests

Persisters are small populations of quiescent bacterial cells that survive exposure to bactericidal antibiotics and are responsible for many persistent infections and posttreatment relapses. However, little is known about how to effectively kill persister bacteria. In the work presented here, we found that colistin, a membrane-active antibiotic, was highly active against Escherichia coli persisters at high concentrations (25 or 50 μg/ml). At a clinically relevant lower concentration (10 μg/ml), colistin alone had no apparent effect on E. coli persisters. In combination with other drugs, this concentration of colistin enhanced the antipersister activity of gentamicin and ofloxacin but not that of ampicillin, nitrofurans, and sulfa drugs in vitro The colistin enhancement effect was most likely due to increased uptake of the other antibiotics, as demonstrated by increased accumulation of fluorescence-labeled gentamicin. Interestingly, colistin significantly enhanced the activity of ofloxacin and nitrofurantoin but not that of gentamicin or sulfa drugs in the murine model of urinary tract infection. Our findings suggest that targeting bacterial membranes is a valuable approach to eradicating persisters and should have implications for more effective treatment of persistent bacterial infections.

Topics: Animals; Anti-Bacterial Agents; Cell Membrane; Colistin; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Synergism; Escherichia coli Infections; Escherichia coli K12; Female; Gentamicins; Mice, Inbred C3H; Microbial Sensitivity Tests; Urinary Tract Infections; Uropathogenic Escherichia coli

Topics: Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Klebsiella Infections; Klebsiella pneumoniae; Plasmids

In 2015, scientists reported the emergence of the plasmid-encoded mcr-1 gene conferring bacterial resistance to the antibiotic colistin (1), signaling potential emergence of a pandrug-resistant bacterium. In May 2016, mcr-1-positive Escherichia coli was first isolated from a specimen from a U.S. patient (2) when a Pennsylvania woman was evaluated for a urinary tract infection. The urine culture and subsequent testing identified the gene in an extended-spectrum beta-lactamase (ESBL)-producing E. coli with reduced susceptibility to colistin. The patient had no international travel for approximately 1 year, no livestock exposure, and a limited role in meal preparation with store-bought groceries; however, she had multiple and repeated admissions to four medical facilities during 2016.

Topics: Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Female; Humans; Pennsylvania; Urinary Tract Infections

Topics: Adult; Algeria; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Humans; Male; Plasmids

Recent findings have identified Escherichia coli strains that are pan-β-lactam susceptible (PBL-S) but piperacillin-tazobactam resistant (TZP-R) in vitro We assessed the in vivo significance of this resistance profile in a neutropenic murine pneumonia model using humanized exposures of TZP with 18 clinical E. coli isolates, 8 TZP-S/PBL-S and 10 genotypically confirmed TZP-R/PBL-S. Despite phenotypically and genotypically defined resistance, TZP displayed efficacy against these isolates. Additional studies are required to define the clinical implications of these TZP-R/PBL-S strains.

Topics: Animals; Anti-Bacterial Agents; Cephalosporins; Colistin; Culture Media; Disease Models, Animal; Drug Administration Schedule; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Female; Humans; Mice; Mice, Inbred ICR; Microbial Sensitivity Tests; Neutropenia; Penicillanic Acid; Piperacillin; Piperacillin, Tazobactam Drug Combination; Tobramycin; Treatment Outcome

Topics: Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; History, 21st Century; Humans; Japan

Eravacycline (formerly TP-434) was evaluated in vitro against pre-established biofilms formed by a uropathogenic Escherichia coli strain. Biofilms were eradicated by 0.5 μg/ml eravacycline, which was within 2-fold of the MIC for planktonic cells. In contrast, colistin and meropenem disrupted biofilms at 32 and 2 μg/ml, respectively, concentrations well above their respective MICs of 0.5 and 0.03 μg/ml. Gentamicin and levofloxacin eradicated biofilms at concentrations within 2-fold of their MICs.

Topics: Anti-Bacterial Agents; Biofilms; Colistin; Colony Count, Microbial; Escherichia coli Infections; Gentamicins; Humans; Levofloxacin; Meropenem; Microbial Sensitivity Tests; Tetracyclines; Thienamycins; Urinary Tract Infections; Uropathogenic Escherichia coli

Polymyxin E shows effective treatment of the infection induced by resistant gramnegative bacteria, but its nephrotoxicity severely limits the clinical application of this drug. In this work, methoxypolyethylene glycols 2000 (mPEG2K)-polymyxin E (PME) was synthesized via chemical grafting reaction and had been characterized. The antimicrobial activity and cytotoxicity of mPEG2K-PME in vitro were investigated on Escherichia coli and HK-2 cells, separately. Intra-abdominal infection model was further established in order to study the therapeutic effect and the toxic effect on kidney of mice. The results showed that mPEG2K-PME exhibited significant inhibitory effect on Escherichia coli and had a lower toxicity on HK-2 cells in vitro. At the same time, mPEG2K-PME had a good efficacy in the treatment of Escherichia coli infected mice in vivo. Moreover, nephrotoxicity caused by mPEG2K-PME was significantly reduced compared to free PME. mPEG2K-PME is promising in development of new preparations with high efficiency and low toxicity.

Topics: Animals; Cell Line; Colistin; Escherichia coli; Escherichia coli Infections; Humans; Kidney; Mice; Polyethylene Glycols

Topics: Adolescent; Animals; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Escherichia coli; Escherichia coli Infections; Feces; Genotype; Humans; Laos; Male; Microbial Sensitivity Tests; Multilocus Sequence Typing; Swine; Swine Diseases; Zoonoses

Topics: Adaptation, Physiological; Aged, 80 and over; Anti-Bacterial Agents; Cholecystitis; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Female; Humans; Male; Microbial Sensitivity Tests; Sepsis; Urinary Tract Infections

The aim of the present study was to investigate the in vitro gastric stability of colistin sulfate (CS) and its antimicrobial activity against Escherichia coli and to study the impact of ETEC O149: F4 (K88) infection in pigs on CS intestinal absorption. The stability profile of CS was evaluated in a simulated gastric fluid (SGF). Antimicrobial activity of CS and its degradation products were examined in a 96-well polystyrene microplate model. The effect of experimental infection with ETEC O149: F4 on CS intestinal absorption was determined by quantification of CS systemic concentration using a validated LC-MS/MS method. A rapid degradation of CS accompanied by an increase in CS antimicrobial activity by comparison with non-degraded CS (P<0.0001) was observed in SGF. Additionally, CS levels were not quantifiable in systemic circulation using a highly sensitive method and concurrent oral challenge did not affect CS absorption in an induction model of subclinical post-weaning diarrhea (PWD).

Topics: Animals; Anti-Bacterial Agents; Biological Availability; Colistin; Diarrhea; Enterotoxigenic Escherichia coli; Escherichia coli Infections; Swine; Swine Diseases; Tandem Mass Spectrometry

The plasmid-mediated colistin resistance gene, mcr-1, was detected in an Escherichia coli isolate from a Danish patient with bloodstream infection and in five E. coli isolates from imported chicken meat. One isolate from chicken meat belonged to the epidemic spreading sequence type ST131. In addition to IncI2, an incX4 replicon was found to be linked to mcr-1. This report follows a recent detection of mcr-1 in E. coli from animals, food and humans in China.

Topics: Animals; Anti-Bacterial Agents; Chickens; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Genotype; Humans; Meat; Plasmids

This study aimed to identify and characterize class 1 and 2 integrons and plasmid-mediated quinolones resistance (PMQR) genes in a collection of 113 multidrug resistance (MDR) Escherichia coli isolated from farm and wild lagomorphs between 2006 and 2008 in Northern Italy. Strains were examined for antimicrobial susceptibility by agar disk diffusion method and E-test for colistin (COL); integrons and gene cassettes content by real-time polymerase chain reaction (PCR) and DNA sequencing; PMQR genes by PCR and DNA sequencing; clonal relatedness by multilocus sequence typing; and plasmids by PCR-based replicon typing. Class 1 integrons were detected in 69 isolates (47 farm rabbits, 14 wild rabbits, and 8 wild hares). No class 2 integrons were found. Five different gene cassettes arrays were identified (aadA1, dfrA1-aadA1, orf in682-dhfrA5, orf in682-dfrA5-orfD ins21, and dfrA17-aadA5). Fifteen percent (17/113) of isolates carried oqxAB, no other PMQR determinants. All but one oqxAB-positive E. coli strains were recovered from farm rabbits. Seven out of 17 strains were associated with the predominant ST238 and carried from three to six different plasmid types, such as IncF, IncHI1, IncI1, IncN, IncP, IncX1, IncY, and ColE. COL resistance was identified in 6/113 strains (5.3%). This study provides new insights on the resistance phenotypes and the prevalence and dissemination of oqxAB in E. coli from farm and wild lagomorphs, suggesting that these animals may be reservoir of these genetic determinants in Italy and thus a potential source of PMQR E. coli for humans. PMQR mediated by oqxAB has not been detected in farm and wild lagomorphs before.

Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; Colistin; Disease Reservoirs; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Integrons; Italy; Lagomorpha; Microbial Sensitivity Tests; Multilocus Sequence Typing; Plasmids; Prevalence

Five carbapenem-resistant strains (three Klebsiella pneumoniae, one Escherichia coli, and one Enterobacter aerogenes) were isolated between 2009 and 2012 at the Verona University Hospital, Italy, during an epidemiological analysis of antibiotic resistance determinants and plasmid profiles in Enterobacteriaceae. Two out of the five strains, K. pneumoniae E530 and E. coli E558, were cultured from bile and abdominal drainage, respectively, of a single patient. The strains were resistant to beta-lactams and fluoroquinolones, and susceptible to tigecycline and colistin. All the strains harboured bla(KPC-3), bla(TEM-1), and bla(OXA-9), and the three K. pneumoniae additionally carried blaSHV-11 and aac(6')Ib. The bla(KPC-3) was inserted in transposon Tn4401a. All the strains hosted an FIIk-type plasmid, and the three K. pneumoniae coharboured an colE-type plasmid. Transconjugants, besides bla(KPC-3), harboured bla(TEM-1) and bla(OXA-9) genes on FIIk-type plasmid. K. pneumoniae E301 was ST258, while strain E530 and C525 belonged to the ST512, and E. coli E558 was ST43. To our best knowledge, this is the first report that strongly supports the transmission of bla(KPC-3) from ST512 K. pneumoniae to E. coli ST43 in a single patient, a phenomenon of both clinical and microbiological importance.

Topics: Abdominal Abscess; Anti-Bacterial Agents; Bacterial Proteins; beta-Lactamases; beta-Lactams; Bile; Colistin; Conjugation, Genetic; DNA Transposable Elements; Drug Resistance, Multiple, Bacterial; Enterobacter aerogenes; Enterobacteriaceae Infections; Escherichia coli; Escherichia coli Infections; Fluoroquinolones; Gene Expression; Humans; Klebsiella Infections; Klebsiella pneumoniae; Minocycline; Plasmids; Tigecycline

The purpose of this study was to evaluate the ocular distribution of intravenously administered colistin in a rabbit uveitis model.. Colistin, a polypeptide antibiotic against the multidrug-resistant (MDR) Gram-negative organisms, was given intravenously to rabbits at 5 mg/kg of body weight starting 24 h after induction of uveitis by intravitreal endotoxin injection. Colistin concentrations were determined by high-performance liquid chromatography-mass spectrometry assay in the aqueous humor, vitreous humor, and plasma 0.5, 3, 6, and 24 h after administration of a single dose.. The maximum colistin concentrations (mean±standard deviation) were found 0.5 h after the end of the intravenous administration and were 9.48±2.0 μg/mL in plasma and 0.62±0.07 μg/mL in the aqueous humor of the inflamed eye. After 24 h, no drug was detectable in the aqueous of the inflamed eyes. Colistin was undetectable in the aqueous of contralateral normal eyes at all time points. Drug concentrations in all the vitreous samples from both inflamed and normal eyes were undetectable, except at the 3-h inflamed eye group, and a colistin concentration of 0.02±0.01 μg/mL was found. Plasma levels of colistin fell to 0.93±0.07 and 0.24±0.08 μg/mL, after 3 and 6 h, respectively, and were not detectable 24 h after the given dose.. In our model, colistin did not reach therapeutically relevant levels in the aqueous and in the vitreous humor of rabbit eyes. The findings suggest a limited role for intravenously administered colistin in the treatment of Gram-negative bacterial endophthalmitis.

Topics: Animals; Anti-Bacterial Agents; Aqueous Humor; Colistin; Disease Models, Animal; Escherichia coli; Escherichia coli Infections; Eye; Injections, Intravenous; Microbial Sensitivity Tests; Rabbits; Tissue Distribution; Uveitis; Vitreous Body

Limited antimicrobial agents are available for the treatment of implant-associated infections caused by fluoroquinolone-resistant Gram-negative bacilli. We compared the activities of fosfomycin, tigecycline, colistin, and gentamicin (alone and in combination) against a CTX-M15-producing strain of Escherichia coli (Bj HDE-1) in vitro and in a foreign-body infection model. The MIC and the minimal bactericidal concentration in logarithmic phase (MBC(log)) and stationary phase (MBC(stat)) were 0.12, 0.12, and 8 μg/ml for fosfomycin, 0.25, 32, and 32 μg/ml for tigecycline, 0.25, 0.5, and 2 μg/ml for colistin, and 2, 8, and 16 μg/ml for gentamicin, respectively. In time-kill studies, colistin showed concentration-dependent activity, but regrowth occurred after 24 h. Fosfomycin demonstrated rapid bactericidal activity at the MIC, and no regrowth occurred. Synergistic activity between fosfomycin and colistin in vitro was observed, with no detectable bacterial counts after 6 h. In animal studies, fosfomycin reduced planktonic counts by 4 log(10) CFU/ml, whereas in combination with colistin, tigecycline, or gentamicin, it reduced counts by >6 log(10) CFU/ml. Fosfomycin was the only single agent which was able to eradicate E. coli biofilms (cure rate, 17% of implanted, infected cages). In combination, colistin plus tigecycline (50%) and fosfomycin plus gentamicin (42%) cured significantly more infected cages than colistin plus gentamicin (33%) or fosfomycin plus tigecycline (25%) (P < 0.05). The combination of fosfomycin plus colistin showed the highest cure rate (67%), which was significantly better than that of fosfomycin alone (P < 0.05). In conclusion, the combination of fosfomycin plus colistin is a promising treatment option for implant-associated infections caused by fluoroquinolone-resistant Gram-negative bacilli.

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Biofilms; Colistin; Colony Count, Microbial; Dose-Response Relationship, Drug; Drug Resistance, Multiple, Bacterial; Drug Synergism; Drug Therapy, Combination; Escherichia coli; Escherichia coli Infections; Foreign Bodies; Fosfomycin; Gentamicins; Guinea Pigs; Male; Microbial Sensitivity Tests; Minocycline; Polytetrafluoroethylene; Prostheses and Implants; Tigecycline

A surveillance study to identify patients from the community with Escherichia coli resistant to broad-spectrum cephalosporins discovered two isolates that were also resistant to polymyxin B and colistin. One isolate from a patient in the community and a second from a patient who received multiple courses of polymyxin B also possessed a CTX-M-15 enzyme. Resistance to cationic peptides in E. coli is unusual, and testing for susceptibility to these agents should be performed.

Topics: Aged, 80 and over; Anti-Bacterial Agents; Colistin; Escherichia coli; Escherichia coli Infections; Female; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Polymyxin B; Polymyxins

There has been a resurgence of interest in the use of colistin for the treatment of multidrug-resistant Gram-negative bacterial infections. A more favorable infection outcome is observed when colistin is used in combination with carbapenems. We present a patient with severe New Delhi metallo-β-lactamase-1 Escherichia coli infection who developed convulsions rapidly followed by acute respiratory muscle weakness and apnoea during treatment with colistin and meropenem. Chromatographic assay showed a "trough" colistin level that was approximately fourfold higher than previously reported maximum steady-state colistin plasma levels in critically ill patients. The patient's renal clearance never necessitated dose adjustments, suggesting that the observed high plasma colistin level might be due to impaired non renal elimination. Although meropenem itself has very low neurotoxic potential, its concomitant use with colistin may have elicited colistin neurotoxicity.

Topics: Anti-Bacterial Agents; Apnea; beta-Lactamases; Chromatography; Colistin; Drug Resistance, Multiple, Bacterial; Drug Therapy, Combination; Escherichia coli; Escherichia coli Infections; Humans; Male; Meropenem; Middle Aged; Plasma; Seizures; Thienamycins

Topics: Bacteremia; beta-Lactamases; Calciphylaxis; Coinfection; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Humans; Klebsiella Infections; Klebsiella pneumoniae; Middle Aged; Minocycline; Tigecycline

During the last few years, acquired resistance to colistin in Escherichia coli, but also in other bacterial species, has been reported. It has been shown that the disk diffusion test is not a reliable method for the detection of this resistance. Therefore, there is a need for a reliable and cheap test to determine colistin susceptibility of pathogenic E. coli strains. In the current research, the colistin susceptibility of E. coli isolated during the period 2005-2006 from pigs was determined. Results obtained with the Kirby Bauer disk diffusion test (Neosensitabs, Rosco), the disk prediffusion test (Neosensitabs, Rosco) and the E-test (AB Biodisk) were compared with the results of the reference agar dilution assay. The MIC values or inhibition zones showed a bimodal distribution for the results obtained by all test methods, except the disk diffusion assay, suggesting acquired resistance in 15 strains (9.6%). The E-test and disk prediffusion assay generated results within acceptable levels compared to the reference agar dilution assay. The categorical agreement with the results obtained by the agar dilution method were good to very good for all tests, except the disk diffusion assay. In conclusion, current results suggest that, in addition to the E-test, the disk prediffusion test is a reliable, alternative agar-based colistin susceptibility method for testing colistin susceptibility of E. coli isolates in diagnostic bacteriology.

Topics: Animals; Anti-Bacterial Agents; Colistin; Disk Diffusion Antimicrobial Tests; Escherichia coli; Escherichia coli Infections; Swine; Swine Diseases

Klebsiella pneumoniae carbapenemase (KPC) 3-producing Escherichia coli was isolated from a carrier of KPC-3-producing K. pneumoniae. The KPC-3 plasmid was identical in isolates of both species. The patient's gut flora contained a carbapenem-susceptible E. coli strain isogenic with the KPC-3-producing isolate, which suggests horizontal interspecies plasmid transfer.

Topics: Aged, 80 and over; Anti-Bacterial Agents; Bacterial Proteins; beta-Lactamases; beta-Lactams; Colistin; Conjugation, Genetic; Drug Resistance, Bacterial; Drug Therapy, Combination; Ertapenem; Escherichia coli; Escherichia coli Infections; Gastrointestinal Tract; Humans; Israel; Klebsiella Infections; Klebsiella pneumoniae; Male; Metronidazole; Plasmids; Vancomycin

Lactoferrin has antimicrobial activity associated with peptide fragments lactoferricin (LFC) and lactoferrampin (LFA) released on digestion. These two fragments have been expressed in Photorhabdus luminescens as a fusion peptide linked to protein cipB. The construct cipB-LFC-LFA was tested as an alternative to antimicrobial growth promoters in pig production. Sixty piglets with an average live body weight of 5.42 (sem 0.59) kg were challenged with enterotoxigenic Escherichia coli and randomly assigned to four treatment groups fed a maize-soyabean meal diet containing either no addition (C), cipB at 100 mg/kg (C+B), cipB-LFC-LFA at 100 mg/kg (C+L) or colistin sulfate at 100 mg/kg (C+CS) for 3 weeks. Compared with C, dietary supplementation with C+L for 3 weeks increased daily weight gain by 21 %, increased recovery from diarrhoea, enhanced serum glutathione peroxidase (GPx), peroxidase (POD) and total antioxidant content (T-AOC), liver GPx, POD, superoxide dismutase and T-AOC, Fe, total Fe-binding capacity, IgA, IgG and IgM levels (P < 0.05), decreased the concentration of E. coli in the ileum, caecum and colon (P < 0.05), increased the concentration of lactobacilli and bifidobacteria in the ileum, caecum and colon (P < 0.05), and promoted development of the villus-crypt architecture of the small intestine. Growth performance was similar between C+L- and C+CS-supplemented pigs. The present results indicate that LFC-LFA is an effective alternative to the feed antibiotic CS for enhancing growth performance in piglets weaned at age 21 d.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Antioxidants; Bacterial Proteins; Cattle; Colistin; Diarrhea; Dietary Supplements; Enterotoxigenic Escherichia coli; Escherichia coli Infections; Genetic Engineering; Intestinal Mucosa; Lactoferrin; Lactoglobulins; Liver; Male; Peptide Fragments; Random Allocation; Recombinant Proteins; Swine; Swine Diseases; Weaning

Shiga-toxigenic E. coli (STEC) strains that produce Shiga toxin Stx2e cause oedema disease in weaned piglets. The purpose of the present study was to investigate the impact of Stx2e released in mesenteric lymph nodes on disease pathogenesis. Colistin and ampicillin were intramuscularly administered to piglets of the experimental group simultaneously challenged with STEC strain, type O139:F18ab, Stx2e+. Piglets of the control group were challenged with STEC only. The strain was naturally resistant to ampicillin and susceptible to colistin. After the challenge, colonisation of the intestines was observed in both antibiotic-treated piglets and control piglets without antibiotic treatment. Histochemistry and scanning electron microscopy revealed sporadic colonisation of the small intestine in the piglets. STEC was detected in the mesenteric lymph nodes of untreated piglets. The clinical manifestations of oedema disease were observed in both groups. In the antibiotic-treated group (11 piglets), oedema disease developed in 10 piglets, eight of which died or were euthanized ante finem. In the untreated group (11 piglets), oedema disease developed in five piglets, four of which died or were euthanized ante finem. We therefore propose that the STEC lysed by colistin suddenly released the toxin from bacterial cells immediately after their passage through the intestinal wall. That could explain a more severe course of oedema disease in the treated piglets. Even though high amounts of STEC were present in the lymph nodes of untreated piglets, the toxin was not released abruptly because the bacterial cells were not damaged.

Topics: Ampicillin; Ampicillin Resistance; Animals; Anti-Bacterial Agents; Case-Control Studies; Colistin; Edema Disease of Swine; Escherichia coli Infections; Feces; Injections, Intramuscular; Intestines; Lymph Nodes; Shiga-Toxigenic Escherichia coli; Swine; Time Factors; Weaning

Edema disease (ED) of pigs is an enterotoxaemic disease caused by enterotoxaemic Escherichia coli (ETEEC) infection. Antimicrobial therapy for pigs with ED is controversial because it may induce death of sickish piglets. In this study, we investigated the effects in vitro of 7 antimicrobial agents, ampicillin, gentamicin, colistin, bicozamycin, fosfomycin, sulfamethoxazole-trimethoprim and enrofloxacin, on the release and production of shiga toxin (Stx) 2e by ETEEC strains. We found that more Stx 2e accumulated in the bacterial cells than was released into supernatant. Associated with inhibition of cell wall synthesis, the exposure to ampicillin or fosfomycin increased the release of Stx 2e. The production levels of Stx 2e in all antimicrobial-treated cultures were equal to the level in the control or less than in the control. These results suggest that cell wall synthesis inhibitors, such as ampicillin and fosfomycin, may change for the worse in the signs in ETEEC infectious pigs. On the other hand, gentamicin, colistin, bicozamycin and enrofloxacin may be useful for the treatment of pigs with ED.

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Bridged Bicyclo Compounds, Heterocyclic; Cell Wall; Colistin; Edema Disease of Swine; Enrofloxacin; Escherichia coli; Escherichia coli Infections; Fluoroquinolones; Fosfomycin; Gentamicins; Quinolones; Shiga Toxin 2; Sus scrofa; Time Factors; Trimethoprim, Sulfamethoxazole Drug Combination

An animal study was performed to investigate the efficacy of two glycopeptides and two cationic peptides in the prevention of lethality in a septic shock rat model. Adult Wistar rats were given an intraperitoneal injection of 2x10(10) CFU of Escherichia coli ATCC 25922, with the exception of an uninfected control group (C0). Animals were randomized to receive, immediately after bacterial challenge, intraperitoneally isotonic sodium chloride solution (control group C1), 3 mg/Kg teicoplanin (group 1), 7 mg/Kg vancomycin (group 2), 1 mg/Kg colistin (group 3), 1 mg/Kg buforin II (group 4), or 60 mg/Kg piperacillin (group C(PIP)). In addition, four groups (1a, 2a, 3a, and 4a) received the above mentioned drugs in combination with piperacillin. All compounds and combinations significantly reduced the lethality and the number of E. coli in abdominal fluid compared with C1 group, with the exception of the glycopeptides. Colistin and buforin II combined with piperacillin significantly decreased the lethality compared with piperacillin alone. Finally, colistin, buforin II, and teicoplanin significantly reduced plasma endotoxin concentration in comparison with piperacillin and saline treatment. Antimicrobial peptides and teicoplanin act as antiendotoxin agents and enhance the efficacy of piperacillin.

Topics: Animals; Anti-Bacterial Agents; Colistin; Disease Models, Animal; Drug Therapy, Combination; Escherichia coli; Escherichia coli Infections; Injections, Intraperitoneal; Male; Penicillins; Piperacillin; Proteins; Random Allocation; Rats; Rats, Wistar; Shock, Septic; Teicoplanin; Vancomycin

Topics: Amoxicillin; Animals; Animals, Newborn; Anti-Bacterial Agents; Cephalosporins; Colistin; Diarrhea; Drug Resistance, Microbial; Enrofloxacin; Escherichia coli; Escherichia coli Infections; Fluoroquinolones; Microbial Sensitivity Tests; Nebramycin; Neomycin; Quinolones; Spain; Swine; Swine Diseases

The susceptibility of Escherichia coli K1, Salmonella enteritidis, Salmonella typhimurium strains and their adaptative forms resistant to colistine (Colr forms) was compared with respect to their sensitivity to the bactericidal action of normal cord serum and normal bovine serum. It has been shown that the Colr forms are more susceptible to sera as compared to initial strains. The increase of sensitivity of the Colr forms is connected with structural changes within bacterial cell wall which is the target for complement as well as for colistine.

Topics: Animals; Anti-Bacterial Agents; Blood Bactericidal Activity; Cattle; Child; Colistin; Colony Count, Microbial; Complement Pathway, Alternative; Diarrhea; Drug Resistance, Microbial; Escherichia coli; Escherichia coli Infections; Feces; Fetal Blood; Humans; Salmonella; Salmonella Infections

Pharmacodynamics studies consider three main parameters: the size of the bacterial population, the concentration of the antibiotic and the duration of its action. The pharmacodynamic characteristics of colistin were studied in vitro with Escherichia coli. The bacterial kinetics were fitted using differential equations. The mathematical model gave qualitative and quantitative information about the characteristics of the antibiotic-bacteria association. Above all, when linked to a pharmacokinetic model, the model permitted the prediction of the drug's efficiency. Simulations of various dosage levels in which the administration route, dose size, or interval between doses varied, permitted a more rational optimization than a prediction of efficacy based on the time taken to achieve antibiotic plasmatic concentrations above the minimal inhibitory concentration. Pharmacokinetic/pharmacodynamic modeling seems to be an interesting possibility for determining antibiotic dosing levels during the preclinical phase.

Topics: Animals; Anti-Bacterial Agents; Colistin; Escherichia coli; Escherichia coli Infections; Microbial Sensitivity Tests; Models, Biological; Time Factors

White blood cell counts and nitroblue tetrazolium dye tests were performed in three groups of dogs before and after the injection of Escherichia coli using colistimethate sodium and cephalothin sodium in the second and third groups, respectively, prior to the induction of sepsis. The response was a diminished white blood count and increased nitroblue tetrazolium dye test percentage in all groups. When antibiotic administration was performed prior to the induction of sepsis, the increase in the nitroblue tetrazolium reduction dye test was much more evident despite the overwhelming dose of bacteria given, suggesting that antibiotics given preoperatively will prevent the toxic effects of bacteria on the neutrophil and will enhance the phagocytic activity of the neutrophil.

Topics: Animals; Cephalothin; Colistin; Dogs; Escherichia coli Infections; Leukocyte Count; Neutrophils; Nitroblue Tetrazolium; Phagocytosis

Between December, 1974, and August 1975, intestinal illness occurred in 55 of 205 infants admitted to the special-care nurseries of a large children's hospital. Escherichia coli serotype 078:K80:H12, which produced a heat-stable enterotoxin, was isolated from 18 of 25 symptomatic infants as compared with 14 of 55 asymptomatic infants (P less than 0.001). Colistin administered prophylactically to 24 culture-negative asymptomatic infants did not prevent colonization in 10, whereas colonization did occur in 22 of 56 not receiving colistin (P = 1.0). This outbreak provides laboratory and epidemiologic evidence that heat-stable enterotoxigenic Esch. coli is pathogenic in human beings and produces infantile diarrhea.

Topics: Adult; Age Factors; Chloramphenicol; Colistin; Diarrhea, Infantile; Disease Outbreaks; Drug Resistance, Microbial; Enterotoxins; Escherichia coli; Escherichia coli Infections; Hot Temperature; Humans; Infant; Nurseries, Infant

The therapeutic potencies of colistin methanesulfonate (CLM) was assessed quantitatively in acute infection of mice with clinically isolated strains of Escherichia coli and Pseudomonas aeruginosa, and effect of different routes of administration was compared. There was no detectable difference in the therapeutic effect of CLM when intramuscular (im) or intravenous (iv) administration was initiated one hour after the infection. On the other hand, a significant difference in ED50 given by im and iv administrations was observed, indicating the superiority of iv administration, when the treatment started 4 to approximately hours after the infection. No difference in the therapeutic effect of polymyxin B (PMB) and tetracycline (TC) administered via either im or iv route was found even in the delayed administration. In contrast to PMB and TC, lower toxicity of CLM was determined when it was administered iv rather than im.

Topics: Acute Disease; Animals; Bacterial Infections; Colistin; Escherichia coli; Escherichia coli Infections; Female; Injections, Intramuscular; Injections, Intravenous; Male; Mesylates; Mice; Polymyxins; Pseudomonas aeruginosa; Pseudomonas Infections; Tetracycline

The identity of 693 pathogenic bacilli isolated from 2,175 urine specimens cultured during a two-year period in southeastern New Mexico is presented along with results of sensitivity testing by Kirby-Bauer technique. The pattern of infections and sensitivity studies in hospitalized patients is compared with that of office patients and contrasted with results noted in other areas.

Topics: Canada; Citrobacter; Colistin; Drug Evaluation, Preclinical; Epidemiologic Methods; Escherichia coli; Escherichia coli Infections; Female; Gentamicins; Humans; In Vitro Techniques; Klebsiella; Male; Microbial Sensitivity Tests; Minnesota; Nalidixic Acid; New Mexico; Nitrofurantoin; Pennsylvania; Proteus; Pseudomonas; Urinary Tract Infections; Urine

The sensitivity patterns of strains of enteropathogenic Escherichia coli to nine antibiotics were determined. Most strains were sensitive to gentamicin, kanamycin, neomycin, and colistin. Sensitivity to cephalexin was generally greater than sensitivity to ampicillin. Compared with sensitivity patterns of strains isolated in previous years, no significant change in sensitivity patterns of recently isolated strains was detected. All ampicillin-resistant strains destroyed the drug by producing beta-lactamase. The activity of this enzyme against cephalexin was significantly lower than its activity against ampicillin. The role of beta-lactamase, the correlation between its production and resistance to beta-lactamase antibiotics, and the similarity between beta-lactamase produced by EEC and the classified beta-lactamases produced by other enteric bacteria and Escherichia coli, are discussed.

Topics: Amidohydrolases; Ampicillin; Anti-Bacterial Agents; Cephalexin; Cephalosporinase; Chloramphenicol; Colistin; Escherichia coli; Escherichia coli Infections; Feces; Gastroenteritis; Gentamicins; Humans; Infant; Infant, Newborn; Kanamycin; Microbial Sensitivity Tests; Penicillin Resistance; Penicillinase; Serotyping; Streptomycin; Tetracycline

Topics: Ampicillin; Anti-Bacterial Agents; Colistin; Diarrhea, Infantile; Escherichia coli; Escherichia coli Infections; Gentamicins; Humans; Infant; Infant, Newborn; Kanamycin; Methods; Microbial Sensitivity Tests; Penicillin Resistance; Streptomycin

Topics: Ampicillin; Anti-Bacterial Agents; Carbenicillin; Cephalothin; Chloramphenicol; Colistin; Dicloxacillin; Escherichia coli Infections; Gentamicins; Humans; Infant, Newborn; Infant, Newborn, Diseases; Infant, Premature, Diseases; Pseudomonas Infections; Sepsis; Staphylococcal Infections; Streptococcal Infections

Subphrenic abscess is still a significant hazard which complicates surgical procedures as well as certain abdominal catastrophes. This is a report of 88 patients with subphrenic abscess at St. Vincent's Hospital and Medical Center of New York from 1954 through 1971. There were 46 males and 42 females, ranging from 2 to 88 years. Operations on the stomach, duodenum and biliary tract were the major causes. The causative organisms in order of frequency were: E coli (41.6%), Staphylococcus (41.6%), Aerobacter aerogenes (23.3%), Proteus (20%), Streptococci (18.3%) and Pseudomonas (8.3%). Penicillin and tetracycline, the antibiotics most commonly chosen on an empiric basis, proved effective in only 38% of cases. On the other hand, kanamycin, chloramphenicol and cephalothin were effective in 90%, 85% and 70% of cases respectively. The overall mortality rate was 15%. Nine of the 21 patients (42.8%) treated with antibiotics alone died while 11 of 67 patients (10.6%) treated with antibiotics and surgical drainage died. Some of the latter deaths occurred in patients treated with prolonged antibiotic therapy and operated on only as a last resort. In this series subphrenic abscess was best treated by early surgical drainage combined with the use of appropriate antibiotics.

Topics: Abdominal Injuries; Adolescent; Adult; Aged; Anti-Bacterial Agents; Child; Child, Preschool; Chloramphenicol; Colistin; Drug Resistance, Microbial; Escherichia coli Infections; Female; Humans; Infant; Kanamycin; Male; Microbial Sensitivity Tests; Middle Aged; Postoperative Complications; Radiography; Staphylococcal Infections; Subphrenic Abscess; Surgical Procedures, Operative

Topics: Ampicillin; Cephaloridine; Chloramphenicol; Colistin; Conjugation, Genetic; Escherichia coli; Escherichia coli Infections; Extrachromosomal Inheritance; Gentamicins; Humans; Japan; Kanamycin; Microbial Sensitivity Tests; Nalidixic Acid; Penicillin Resistance; Streptomycin; Sulfanilamides; Tetracycline

Topics: Ampicillin; Anti-Bacterial Agents; Bacteria; Bacterial Infections; Bacteriuria; Chloramphenicol; Colistin; Drug Resistance, Microbial; Enterococcus faecalis; Escherichia coli; Escherichia coli Infections; Humans; Hungary; Kanamycin; Klebsiella; Microbial Sensitivity Tests; Nalidixic Acid; Neomycin; Nitrofurantoin; Penicillin Resistance; Polymyxins; Proteus; Proteus Infections; Proteus mirabilis; Pseudomonas aeruginosa; Streptomycin; Tetracycline; Time Factors; Urinary Tract Infections; Urine

Topics: Ampicillin; Animals; Colistin; Diuresis; Escherichia coli; Escherichia coli Infections; Female; Furosemide; Kidney; Pyelonephritis; Rats; Water-Electrolyte Balance

Topics: Cephalothin; Colistin; Enterococcus faecalis; Escherichia coli Infections; Gentamicins; Humans; Kanamycin; Kidney Failure, Chronic; Kidney Function Tests; Male; Novobiocin; Postoperative Complications; Prostatectomy; Pseudomonas aeruginosa; Pseudomonas Infections; Streptococcal Infections; Urinary Tract Infections; Urologic Diseases

Topics: Age Factors; Child, Preschool; Colistin; Dosage Forms; Drug Resistance, Microbial; Escherichia coli Infections; Feces; Female; Fluorescent Antibody Technique; Gastroenteritis; Humans; Infant; Infant, Newborn; Male; Microbial Sensitivity Tests; Tablets

Topics: Acinetobacter; Adolescent; Adult; Alcaligenes; Arm Injuries; Bacillus subtilis; Blast Injuries; Blood; Cephalothin; Chloramphenicol; Colistin; Escherichia coli Infections; Humans; Klebsiella Infections; Klebsiella pneumoniae; Leg Injuries; Male; Penicillin Resistance; Penicillins; Proteus Infections; Proteus mirabilis; Pseudomonas aeruginosa; Pseudomonas Infections; Serratia marcescens; Streptomycin; Warfare; Wound Infection

Topics: Animals; Animals, Newborn; Cattle; Cattle Diseases; Colistin; Culture Media; Diarrhea; Escherichia coli; Escherichia coli Infections; Microbial Sensitivity Tests

Topics: Animals; Anti-Bacterial Agents; Bacteria; Blood Proteins; Colistin; Culture Media; Drug Resistance, Microbial; Escherichia coli Infections; Gentamicins; Hydrogen-Ion Concentration; Kanamycin; Klebsiella Infections; Male; Mice; Mice, Inbred Strains; Microbial Sensitivity Tests; Protein Binding; Pseudomonas aeruginosa; Pseudomonas Infections; Staphylococcal Infections; Staphylococcus; Streptomycin

Topics: Ampicillin; Chloramphenicol; Colistin; Entamoeba histolytica; Escherichia coli; Escherichia coli Infections; Feces; Female; Gastroenteritis; Gentamicins; Giardia; Humans; Infant; Kanamycin; Male; Microbial Sensitivity Tests; Nalidixic Acid; Neomycin; Salmonella; Shigella; Streptomycin; Tetracycline; Time Factors; Trichuris

Topics: Adolescent; Adult; Age Factors; Aged; Colistin; Cross Infection; Escherichia coli Infections; Female; Fever; Humans; Kanamycin; Klebsiella Infections; Leukocyte Count; Male; Microbial Sensitivity Tests; Middle Aged; Nitrogen; Penicillins; Proteus Infections; Pseudomonas Infections; Retrospective Studies; Sepsis; Sex Factors; Shock; Uremia

Topics: Acute Disease; Anti-Bacterial Agents; Chloramphenicol; Cholecystitis; Chronic Disease; Colistin; Escherichia coli Infections; Penicillins; Staphylococcal Infections; Streptococcal Infections; Streptomycin

Topics: Anti-Bacterial Agents; Antibodies; Colistin; Cross Infection; Disease Outbreaks; Drug Resistance, Microbial; Escherichia coli Infections; Gastroenteritis; Hospital Design and Construction; Humans; Infant; Infant, Newborn; Patient Isolators

Topics: Animals; Chloramphenicol; Colistin; Drug Synergism; Escherichia coli Infections; Female; Mice; Staphylococcal Infections

Topics: Adult; Ampicillin; Anti-Bacterial Agents; Antibodies; Carbenicillin; Cell Membrane; Colistin; Complement System Proteins; Drug Antagonism; Drug Synergism; Escherichia coli; Escherichia coli Infections; Gentamicins; Humans; Microbial Sensitivity Tests; Pseudomonas aeruginosa; Pseudomonas Infections; Receptors, Drug; Serum Albumin, Bovine; Streptomycin; Tetracycline

Topics: Adult; Aged; Ampicillin; Anti-Bacterial Agents; Chloramphenicol; Chronic Disease; Colistin; Depression, Chemical; Drug Synergism; Erythromycin; Escherichia coli Infections; Female; Follow-Up Studies; Humans; Kanamycin; Klebsiella Infections; Male; Middle Aged; Nitrofurantoin; Oleandomycin; Oxacillin; Penicillins; Polymyxins; Proteus Infections; Pyelonephritis; Staphylococcal Infections; Stimulation, Chemical; Streptococcal Infections; Streptomycin; Sulfonamides; Tetracycline

Topics: Adolescent; Adult; Aged; Bacteriuria; Cephalothin; Chloramphenicol; Chronic Disease; Colistin; Drug Resistance, Microbial; Escherichia coli Infections; Female; Gentamicins; Humans; Kanamycin; Male; Methacycline; Middle Aged; Oxytetracycline; Proteus Infections; Rifampin; Sulfamethoxypyridazine; Urinary Tract Infections

The effect of early bilateral pyelonephritis on urinary concentrating ability was studied in rats injected intravenously with enterococci or Staphylococcus aureus and in rats inoculated with Escherichia coli into the medullae of both kidneys. The mean maximum urinary osmolality of normal rats was 2352 mOsm/kg of water. Inoculation of E. coli caused reversible pyelonephritis with sterilization of the kidneys within 12 wk. By 1 day after injection the mean maximum urinary osmolality had decreased to about 1100 mOsm. remained at this level for 3 wk, and then rose to normal by 12 wk. After injection of enterococci and staphylococci, the mean maximum urine osmolality decreased over 3-4 days to about 1000 and 800 mOsm respectively. In the enterococcal infection (which is chronic) the maximum urine osmolality remained about 1200 mOsm for at least 12 wk whereas in the staphylococcal infection (which is reversible) the osmolality gradually rose. Antimicrobial therapy of E. coli renal infection with colistimethate sodium and S. aureus infection with ampicillin rapidly reduced bacterial titers in the kidneys with an associated rise in maximum urinary osmolality. Therapy of enterococcal renal infection with ampicillin produced less impressive decreases in bacterial titers in the kidneys and little or no improvement in urinary concentrating ability. With antimicrobial therapy or with the self-limited infections, the rate of increase in concentrating ability was directly correlated with the rate of decrease of bacterial titers. However, there was poor correlation between histological findings in the kidneys and urinary concentrating ability. These studies demonstrate that early experimental pyelonephritis is associated with a concentrating defect that can be rapidly reversed and therefore is not related to permanent renal damage.

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Colistin; Creatinine; Escherichia coli Infections; Kidney; Kidney Concentrating Ability; Male; Osmolar Concentration; Pyelonephritis; Rats; Staphylococcal Infections; Streptococcal Infections; Vasopressins

Topics: Carbohydrate Metabolism; Colistin; Diarrhea, Infantile; Disease Outbreaks; England; Escherichia coli Infections; Gastroenteritis; Gentamicins; Humans; Infant; Infant, Newborn; Liver; Odorants; Parenteral Nutrition; Vomiting

Topics: Abscess; Ampicillin; Anti-Bacterial Agents; Bacteriological Techniques; Cellulitis; Cephalothin; Chloramphenicol; Colistin; Erythromycin; Escherichia coli; Escherichia coli Infections; Hand; Humans; Infections; Kanamycin; Lincomycin; Methicillin; Penicillin Resistance; Penicillins; Polymyxins; Staphylococcal Infections; Staphylococcus; Streptococcal Infections; Streptococcus; Streptomycin; Tetracycline; Wound Infection

Topics: Adult; Burns; Burns, Electric; Candidiasis, Cutaneous; Child; Child, Preschool; Colistin; Escherichia coli Infections; Female; Gentamicins; Humans; Male; Patient Isolators; Penicillins; Polymyxins; Proteus Infections; Pseudomonas Infections; Sepsis; Silver Nitrate; Staphylococcal Infections; Streptococcal Infections; Sulfonamides; Toluene

Topics: Child; Child, Preschool; Colistin; Diarrhea; Drug Resistance, Microbial; Dysentery, Bacillary; Escherichia coli Infections; Humans; Infant; Infant, Newborn; Iran; Neomycin; Polymyxins; Salmonella Infections; Salmonella typhimurium; Shigella; Sulfonamides

Topics: Colistin; Diarrhea, Infantile; Escherichia coli Infections; Female; Gastroenteritis; Humans; Infant; Male; Solutions; Sucrose

Topics: Animals; Anti-Bacterial Agents; Bacteriuria; Cephaloridine; Cephalothin; Colistin; Escherichia coli Infections; Female; Gentamicins; Kidney; Models, Biological; Naphthacenes; Proteus Infections; Pyelonephritis; Rats

Topics: Anti-Bacterial Agents; Colistin; Diarrhea, Infantile; Disease Outbreaks; Escherichia coli Infections; Humans; Infant; Male; New Jersey

Topics: Ampicillin; Anti-Bacterial Agents; Child; Chloramphenicol; Colistin; Escherichia coli; Escherichia coli Infections; Gastroenteritis; Humans; Kanamycin; Neomycin; Penicillin Resistance; Salmonella; Salmonella Infections; Tetracycline

Topics: Agar; Animals; Anti-Bacterial Agents; Chloramphenicol; Colistin; Diffusion; Dihydrostreptomycin Sulfate; Drug Resistance, Microbial; Escherichia coli; Escherichia coli Infections; Furazolidone; Hemolysis; Kanamycin; Microbial Sensitivity Tests; Neomycin; Paper; Serotyping; Swine; Swine Diseases; Tetracycline

Topics: Adult; Ampicillin; Anti-Bacterial Agents; Cephaloridine; Child; Chloramphenicol; Chlortetracycline; Colistin; Enteritis; Erythromycin Ethylsuccinate; Escherichia coli; Escherichia coli Infections; Humans; Kanamycin; Nalidixic Acid; Neomycin; Oleandomycin; Oxytetracycline; Penicillin Resistance; Polymyxins; Streptomycin; Tetracycline; Viomycin

Topics: Colistin; Enterobacteriaceae Infections; Escherichia coli Infections; Humans; Klebsiella Infections; Polymyxins; Pseudomonas Infections

Topics: Adult; Child, Preschool; Colistin; Dysentery, Bacillary; Escherichia coli Infections; Gastroenteritis; Humans; Infant

Topics: Antibodies; Colistin; Escherichia coli; Escherichia coli Infections; Humans; Infant; Infant, Newborn; Infant, Newborn, Diseases

Topics: Colistin; Cross Infection; Escherichia coli; Escherichia coli Infections; Humans; Infant, Newborn; Infant, Premature, Diseases; Italy

Topics: Aged; Catheterization; Chloramphenicol; Clostridium perfringens; Colistin; Dextrans; Enterobacter; Erythromycin; Escherichia coli Infections; Female; Humans; Hydrocortisone; Isoproterenol; Kanamycin; Klebsiella; Male; Methicillin; Middle Aged; Ointments; Penicillins; Sepsis; Staphylococcal Infections; Streptomycin; Strongyloides; Veins

Topics: Alanine; Amino Acids; Anti-Bacterial Agents; Arginine; Aspartic Acid; Child; Chloramphenicol; Chlortetracycline; Colistin; Drug Resistance, Microbial; Enteritis; Escherichia coli; Escherichia coli Infections; Glutamates; Glycine; Humans; In Vitro Techniques; Oxytetracycline; Proline; Serine; Streptomycin; Viomycin

Topics: Bacteriuria; Colistin; Cystitis; Escherichia coli Infections; Humans; Pseudomonas Infections; Pyelonephritis; Sulfonic Acids; Urethritis

Gentamicin was of value in the treatment of chronic urinary tract infections caused by multiresistant bacterial strains for which no atoxic antibiotic was available. The treatment was carried out after alkalinization of the patient's urine. With the dosage given, gentamicin gave a low serum and a relatively high urine concentration. Excretion of active gentamicin in the urine was high even in patients with impaired renal function. The results of treatment of complicated chronic urinary tract infections with initial gentamicin and following long-term therapy showed negative urinary cultures in 12 out of 24 patients within one to 14 months of follow-up time. To reduce the risk of toxic side effects the dosage was adjusted according to the patient's kidney function. No development of resistance was demonstrated in the bacteria.

Topics: Adult; Aged; Chronic Disease; Colistin; Drug Resistance, Microbial; Escherichia coli Infections; Female; Gentamicins; Humans; Kanamycin; Klebsiella Infections; Male; Middle Aged; Proteus Infections; Urinary Tract Infections

Topics: Adult; Bacteria; Chloramphenicol; Chlortetracycline; Colistin; Erythromycin; Escherichia coli; Escherichia coli Infections; Female; Humans; In Vitro Techniques; Infections; Kanamycin; Male; Middle Aged; Penicillin G; Penicillin Resistance; Pseudomonas aeruginosa; Staphylococcal Infections; Staphylococcus; Streptococcus; Streptomycin; Surgical Wound Infection; Tetracycline

Topics: Child, Preschool; Colistin; Escherichia coli Infections; Female; Gastroenteritis; Humans; Infant; Infant, Newborn; Male; Polymyxins

Topics: Blood Transfusion; Colistin; Drug Resistance, Microbial; Escherichia coli Infections; Feces; Fluorescent Antibody Technique; Gastroenteritis; Greece; Humans; Infant; Infant, Newborn

Topics: Ampicillin; Chloramphenicol; Colistin; Dysentery, Bacillary; Escherichia coli; Escherichia coli Infections; Humans; Infant; Kanamycin; Neomycin; Penicillins; Salmonella; Shigella; Sulfadiazine; Tetracycline

Topics: Bacitracin; Child; Colistin; Drug Therapy; Endocarditis; Endocarditis, Bacterial; Enterobacter aerogenes; Escherichia coli Infections; Humans; Infant; Infant, Newborn; Infant, Newborn, Diseases; Infections; Klebsiella; Liver Abscess; Oxacillin; Penicillins; Pseudomonas Infections; Staphylococcal Infections; Streptococcal Infections; Toxicology

Topics: Anticoagulants; Colistin; Diagnosis; Drug Therapy; Enterobacter; Escherichia coli Infections; Heparin; Hydrocortisone; Kanamycin; Klebsiella; Mannitol; Proteus Infections; Pseudomonas Infections; Sepsis; Streptomycin; Urinary Tract Infections; Urology; Vasodilator Agents

Topics: Anti-Bacterial Agents; Chloramphenicol; Colistin; Drug Resistance; Drug Resistance, Microbial; Drug Therapy; Enterobacter; Escherichia coli Infections; Humans; Klebsiella; Nalidixic Acid; Nitrofurantoin; Proteus Infections; Pseudomonas Infections; Pyelonephritis; Statistics as Topic; Sulfonamides; Tetracycline

Colistimethate sodium (Coly-Mycin) was used in the treatment of 17 patients: 13 had urinary tract infections (two of these had positive blood cultures), three had respiratory tract infections, and one patient had both urinary and respiratory tract infections. In nine of the 17 a foreign body-either a carcinoma, a catheter, or a stone-complicated the infection.The dosage used was 1.1-2.3 mg./lb./day with a maximum in one case of 2.4 g. given over an eight-day period. The organisms so treated included Pseudomonas, six; Aerobacter, six and E. coli, two. Both Pseudomonas and Aerobacter were encountered in three cases.On bacteriological grounds, six patients were cured, eight relapsed, and in three the infecting agent was replaced by another organism. The best responses were obtained in those patients with Pseudomonas infection. Side effects included nausea, vomiting, vertigo, paresthesias, and pain at the site of injection.Colistimethate sodium has a place in the treatment of Gram-negative infections excluding Proteus organisms.

Topics: Colistin; Drug Therapy; Enterobacter; Escherichia coli; Escherichia coli Infections; Geriatrics; Humans; Proteus; Pseudomonas Infections; Respiratory Tract Infections; Toxicology; Urinary Tract Infections

Topics: Anti-Bacterial Agents; Child; Chloramphenicol; Colistin; Cross Infection; Drug Resistance; Drug Resistance, Microbial; Escherichia coli; Escherichia coli Infections; Framycetin; Humans; Kanamycin; Neomycin; Statistics as Topic; Tetracycline

Topics: Antibiotic Prophylaxis; Colistin; Diarrhea; Diarrhea, Infantile; Escherichia coli Infections; Gastroenteritis; Humans; Infant; Infant, Newborn; Infant, Premature, Diseases; Vaccination

Topics: Anti-Bacterial Agents; Colistin; Cross Infection; Diarrhea, Infantile; Drug Resistance, Microbial; Escherichia coli Infections; Female; Furazolidone; Germany, West; Humans; Infant, Newborn; Infant, Premature, Diseases; Polymyxins; Pregnancy; Statistics as Topic

Topics: Colistin; Escherichia coli Infections; Humans; Infant; Infant, Newborn

Topics: Blood; Cerebrospinal Fluid; Colistin; Escherichia coli Infections; Humans; Pseudomonas Infections

Topics: Anti-Bacterial Agents; Bacteriological Techniques; Bacteriuria; Colistin; Enterobacteriaceae; Escherichia coli Infections; Klebsiella; Proteus Infections; Pseudomonas; Pseudomonas Infections; Staphylococcal Infections; Streptococcal Infections; Urinary Tract Infections; Urine

Topics: Acinetobacter; Biomedical Research; Colistin; Enterobacter aerogenes; Escherichia coli Infections; Hydrocortisone; Klebsiella; Neomycin; Otitis Externa; Proteus Infections; Pseudomonas aeruginosa; Pseudomonas Infections; Staphylococcal Infections

Topics: Adolescent; Anti-Bacterial Agents; Antibiotic Prophylaxis; Burns; Child; Chloramphenicol; Colistin; Erythromycin; Escherichia coli Infections; gamma-Globulins; Humans; Immune Sera; Infant; Infant, Newborn; Kanamycin; Novobiocin; Polymyxins; Proteus Infections; Pseudomonas Infections; Salmonella Infections; Sepsis; Serum Albumin; Shigella; Sodium Chloride; Solutions; Staphylococcal Infections; Streptococcal Infections; Tetracycline; Vancomycin

Topics: Amphotericin B; Anti-Bacterial Agents; Chloramphenicol; Colistin; Drug Resistance; Drug Resistance, Microbial; Endocarditis; Endocarditis, Bacterial; Enterobacter aerogenes; Enterobacteriaceae; Erythromycin; Escherichia coli Infections; Kanamycin; Penicillin G; Penicillins; Proteus Infections; Pseudomonas Infections; Ristocetin; Staphylococcal Infections; Streptococcal Infections; Streptomycin; Tetracycline; Vancomycin

Topics: Colistin; Diagnosis, Differential; Enterobacter; Escherichia coli Infections; Glomerulonephritis; Kanamycin; Prognosis; Proteus Infections; Pseudomonas Infections; Pyelonephritis; Staphylococcal Infections

Topics: Colistin; Cross Infection; Diarrhea; Diarrhea, Infantile; Disease Outbreaks; Drug Resistance; Drug Resistance, Microbial; Escherichia coli; Escherichia coli Infections; Feces; Humans; Neomycin; Nitrofurantoin; Polymyxins; Propiophenones; Streptomycin; Sulfathiazoles

Topics: Colistin; Diarrhea; Diarrhea, Infantile; Drug Therapy; Enteropathogenic Escherichia coli; Escherichia coli; Escherichia coli Infections; Feces; Humans; Infant; Neomycin

Topics: Alcaligenes; Anti-Bacterial Agents; Chloramphenicol; Colistin; Diabetes Mellitus; Enterobacteriaceae; Escherichia coli Infections; Female; Humans; Kanamycin; Klebsiella; Neomycin; Nitrofurantoin; Novobiocin; Penicillins; Polymyxins; Proteus Infections; Staphylococcal Infections; Streptomycin; Sulfonamides; Tetracycline; Urinary Tract Infections

Topics: Abortion, Septic; Bacteremia; Chloramphenicol; Cholangitis; Colistin; Escherichia coli Infections; Gastroenteritis; Hydrocortisone; Kanamycin; Polymyxins; Prognosis; Sepsis; Shock, Septic; Streptomycin; Urinary Tract Infections

Topics: Apnea; Colistin; Dexamethasone; Escherichia coli Infections; Femoral Fractures; Fractures, Spontaneous; Hydrocortisone; Injections; Injections, Intramuscular; Osteomyelitis; Spinal Injuries; Tetracycline; Toxicology

Topics: Aging; Angiotensins; Bacteremia; Bacteroides; Chloramphenicol; Colistin; Drug Therapy; Enterobacter aerogenes; Escherichia coli Infections; Humans; Iatrogenic Disease; Kanamycin; Metaraminol; Polymyxins; Postoperative Complications; Proteus; Pseudomonas Infections; Sepsis; Sex; Streptomycin; Sympatholytics; Tetracycline; Urinary Tract Infections

Topics: Colistin; Drug Therapy; Escherichia coli Infections; Humans; Meningitis; Pseudomonas aeruginosa; Pseudomonas Infections; Urinary Tract Infections

Topics: Child; Colistin; Enteritis; Escherichia coli Infections; Humans; Infant; Intraabdominal Infections; Salmonella Infections

Topics: Colistin; Enterobacter; Escherichia coli Infections; Klebsiella; Pseudomonas Infections; Urinary Tract Infections

Topics: Colistin; Escherichia coli Infections; Humans; Respiratory Tract Neoplasms

Topics: Blood Chemical Analysis; Chemical and Drug Induced Liver Injury; Colistin; Diverticulitis; Diverticulitis, Colonic; Escherichia coli Infections; Hepatitis A; Intestinal Perforation; Kidney Diseases; Pathology; Sepsis; Toxicology

Topics: Biometry; Child; Colistin; Diet; Diet Therapy; Enteritis; Escherichia coli Infections; Germany; Germany, West; Humans; Infant; Polymyxins; Statistics as Topic

Topics: Colistin; Enterobacter aerogenes; Enterococcus faecalis; Escherichia coli Infections; Hospitals, General; Humans; Proteus Infections; Pseudomonas aeruginosa; Pseudomonas Infections; Staphylococcal Infections; Streptococcal Infections; Urinary Tract Infections

Topics: Colistin; Cystitis; Escherichia coli Infections; Humans; Male; Prostatic Hyperplasia; Urinary Calculi; Urinary Tract Infections; Urology

Topics: Bacitracin; Child; Chloramphenicol; Colistin; Escherichia coli Infections; Gastroenteritis; Humans; Infant; Infant, Newborn; Kanamycin; Neomycin; Nitrofurantoin; Polymyxins; Proteus Infections; Pseudomonas Infections

Topics: Candidiasis; Colistin; Diarrhea; Diarrhea, Infantile; Enterocolitis; Escherichia coli Infections; Humans; Infant; Intestines; Toxicology

Topics: Colistin; Escherichia coli; Escherichia coli Infections; Gastroenteritis; Humans; Infant

Topics: Anti-Bacterial Agents; Candidiasis; Chloramphenicol; Colistin; Colitis, Ulcerative; Erythromycin; Escherichia coli Infections; Gastrointestinal Hemorrhage; Humans; Intestines; Penicillins; Peptic Ulcer Perforation; Polyps; Proteus Infections; Staphylococcal Infections; Streptomycin; Tetracycline

Topics: Adolescent; Anti-Bacterial Agents; Child; Colistin; Colitis; Drug Therapy; Enterocolitis; Erythromycin; Escherichia coli Infections; Gastroenteritis; Oxytetracycline; Staphylococcal Infections

Topics: Biliary Tract; Chloramphenicol; Chlortetracycline; Cholangitis; Cholecystitis; Colistin; Drug Resistance; Drug Resistance, Microbial; Duodenum; Escherichia coli Infections; Oxytetracycline; Penicillins; Pneumococcal Infections; Staphylococcal Infections; Streptomycin

Topics: Colistin; Diarrhea; Dysentery; Escherichia coli; Escherichia coli Infections; Humans

Topics: Anti-Bacterial Agents; Antibiotics, Antitubercular; Bacillus; Colistin; Erythromycin Ethylsuccinate; Escherichia coli Infections; Gram-Positive Bacteria; Kanamycin; Lacticaseibacillus casei

Topics: Colistin; Diarrhea; Diarrhea, Infantile; Escherichia coli; Escherichia coli Infections; Humans; Infant; Sprains and Strains; Syndrome

Topics: Anti-Bacterial Agents; Colistin; Enteritis; Escherichia coli Infections

Topics: Anti-Bacterial Agents; Child; Colistin; Enteritis; Escherichia coli; Escherichia coli Infections; Humans; Infant

Topics: Anti-Bacterial Agents; Colistin; Escherichia coli Infections; Humans; Kidney; Kidney Diseases; Urinary Tract Infections

Topics: Anti-Bacterial Agents; Child; Colistin; Dyspepsia; Escherichia coli Infections; Humans; Infant

Topics: Anti-Bacterial Agents; Colistin; Communicable Diseases; Escherichia coli Infections; Humans; Urinary Tract Infections

Topics: Anti-Bacterial Agents; Bacillus; Child; Colistin; Escherichia coli; Escherichia coli Infections; Infant; Meningitis

Topics: Anti-Bacterial Agents; Child; Colistin; Escherichia coli; Escherichia coli Infections; Gastroenteritis; Humans; Infant

Topics: Anti-Bacterial Agents; Child; Colistin; Dyspepsia; Escherichia coli; Escherichia coli Infections; Gastrointestinal Diseases; Humans; Infant