tetracycline and Salmonella-Infections--Animal

Poultry and poultry-derived products such as meat and eggs are among the main sources of non-typhoidal Salmonella (NTS) transmission to humans. Therefore, we performed a systematic review and used random-effects meta-analyses to (1) estimate the prevalence of NTS in poultry samples from birds, products and subproducts and environmental samples, (2) examine the diversity and frequency of their serovars and (3) estimate the prevalence and profiles of anti-microbial resistance (AMR) in NTS isolates reported in studies from the Americas. We included 157 studies from 15 countries comprising 261,408 poultry samples and estimated an overall pooled prevalence of 17.9% (95% Confidence Interval: 10.8-26.3) in birds, 21.8% (17.7-26.1) in products and subproducts and 29.5% (24.2-35.1) in environmental samples. At the national level, the prevalence of NTS was heterogeneous across countries with the highest values in Mexico, the United States and Canada. In total, 131 serovars were identified from 13,388 isolates; Heidelberg, Kentucky, Enteritidis and Typhimurium were the most prevalent in the overall top 10 ranking (range 6.5%-20.8%). At the national level, Enteritidis and Typhimurium were identified in most of the countries, though with national differences in their ranks. The prevalence of AMR increased from 24.1% for 1 antibiotic to 36.2% for 2-3 antibiotics and 49.6% for ≥ 4 antibiotics. Kentucky, Heidelberg, Typhimurium and Enteritidis were the serovars with the highest prevalence of AMR. Besides, tetracycline, ampicillin, streptomycin, ceftiofur and amoxicillin-clavulanic acid were the most frequent antibiotics to which NTS showed resistance. In conclusion, NTS was distributed through the avian production chain with high and heterogeneous values of prevalence in poultry samples. Besides, there were distinctive patterns of serovars distribution across countries and an alarming prevalence of AMR among zoonotic serovars.

Topics: Amoxicillin-Potassium Clavulanate Combination; Ampicillin; Animals; Anti-Bacterial Agents; Humans; Ovum; Poultry; Prevalence; Salmonella; Salmonella Infections, Animal; Serogroup; Streptomycin; Tetracycline; United States

Nontyphoidal Salmonella are one of the leading causes of foodborne diseases in the world. As poultry products are recognized as main sources of human salmonellosis, nontyphoidal Salmonella control has become a global issue for the poultry industry. The increasing antimicrobial resistance in poultry-related nontyphoidal Salmonella serovars is a global matter of concern. By monitoring the evolution of antimicrobial resistance, alternative treatments can be identified and possible restrictions in the treatment of systemic human salmonellosis foreseen. A meta-analysis was conducted to assess the profile and temporal evolution of the antimicrobial resistance of nontyphoidal Salmonella of poultry and human origin in Brazil, isolated in the period from 1995 to 2014. Four databases were researched; twenty-nine articles met the eligibility criteria and were included in the meta-analysis. In the nontyphoidal isolates of poultry origin, the highest levels of antimicrobial resistance were verified for sulfonamides (44.3%), nalidixic acid (42.5%), and tetracycline (35.5%). In the human-origin isolates, the resistance occurred mainly for sulfonamides (46.4%), tetracycline (36.9%), and ampicillin (23.6%). Twenty-two articles described results of antimicrobial resistance specifically for Salmonella Enteritidis, also enabling the individual meta-analysis of this serovar. For most antimicrobials, the resistance levels of Salmonella Enteritidis were lower than those found when considering all the nontyphoidal serovars. In the poultry-origin isolates, a quadratic temporal distribution was observed, with reduced resistance to streptomycin in Salmonella Enteritidis and in all nontyphoidal serovars, and a linear increase of resistance to nalidixic acid in Salmonella Enteritidis. In the human-origin isolates, a linear increase was identified in the resistance to nalidixic acid in Salmonella Enteritidis and in all the nontyphoidal isolates, and to gentamicin in Salmonella Enteritidis. Continuous monitoring of the development and spread of antimicrobial resistance could support the measurement of the consequences on poultry and human health.

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Brazil; Drug Resistance, Multiple, Bacterial; Gentamicins; Humans; Microbial Sensitivity Tests; Nalidixic Acid; Poultry Products; Salmonella enteritidis; Salmonella Food Poisoning; Salmonella Infections, Animal; Streptomycin; Tetracycline

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Cattle; Chickens; Chloramphenicol; Drug Resistance, Microbial; Enterobacteriaceae; Escherichia coli; Food Additives; Food Contamination; Gastroenteritis; Humans; Salmonella Infections, Animal; Substance-Related Disorders; Swine; Tetracycline; Typhoid Fever

To evaluate the Salmonella prevalence and its antimicrobial susceptibility in dual-purpose cattle farms, fecal (n = 3964; from cows and calves) and environmental samples (n = 334; personnel, feed, and water sources) were collected over a 1-year period at six farms in the eastern region of Zulia State, Venezuela. Salmonella detection was carried out using standard microbiological culture methods. From 453 isolated Salmonella, antimicrobial susceptibility was tested using a panel of 10 antibiotics by the disk diffusion test method. Overall, the prevalence of Salmonella at the farm was 10.4% (n = 410/3964), being positive for Salmonella in at least in one sample. Salmonella was found in 11% (222/2009) of cows and 9.7% (188/1937) of calves. The prevalence of environmental samples was 10.78% (36/334), where water sources and milkers' hands showed higher occurrence (p < 0.01). Among the Salmonella isolates recovered, 10.2% displayed resistance to tetracyclines, aminoglycosides, cephalosporins, penicillins, sulfonamides, quinolones and fluoroquinolones. Overall, multidrug resistance was 9.1%, and the most common combination was cephalothin-gentamicin-tetracycline, followed by gentamicin-norfloxacin-tetracycline. Over the course of this study, it was found that 100% of the evaluated farms had cattle shedding Salmonella and that the surrounding farm environments were contaminated, which contributed to the cycling of the pathogen at the farms and further contamination of the milk. However, only a low percentage of isolates exhibited significant antimicrobial resistance.

Topics: Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; Cephalosporins; Drug Resistance, Multiple, Bacterial; Farms; Feces; Female; Gentamicins; Microbial Sensitivity Tests; Milk; Prevalence; Salmonella; Salmonella Infections, Animal; Tetracycline; Venezuela

Microbial horizontal gene transfer is a continuous process that shapes bacterial genomic adaptation to the environment and the composition of concurrent microbial ecology. This includes the potential impact of synthetic antibiotic utilization in farm animal production on overall antibiotic resistance issues; however, the mechanisms behind the evolution of microbial communities are not fully understood. We explored potential mechanisms by experimentally examining the relatedness of phylogenetic inference between multidrug-resistant

Topics: Animals; Anti-Bacterial Agents; Drug Resistance, Bacterial; Gene Transfer, Horizontal; Genome, Bacterial; Microbial Sensitivity Tests; Phylogeny; Plasmids; Salmonella Infections, Animal; Salmonella typhimurium; Selection, Genetic; Soil Microbiology; Tetracycline

The antimicrobial resistance of Salmonella strains is rapidly increasing worldwide, which poses significant threats to animal and public health. In this study, a total of 249 porcine Salmonella isolates collected in China during 2008-2015 were examined, including 155 clinical isolates from diseased pigs and 94 nonclinical isolates from healthy pigs. Based on the minimum inhibitory concentration of seven antimicrobial agents, 96.4% of the isolates were resistant to at least one of the tested antibiotics and 81.0% of them showed multidrug resistance. The highest antimicrobial resistance was observed for tetracycline (85.9%), and the lowest was found for cefotaxime (13.3%). The isolates from diseased pigs exhibited significantly higher levels of antimicrobial resistance than those from healthy pigs. Twenty-two isolates from healthy pigs were resistant to ciprofloxacin, which may inhibit the curative effectiveness of fluoroquinolones on bacterial food-borne poisoning and infections in humans caused by contaminated food. Moreover, cefotaxime resistance of the strains isolated from diseased pigs during 2013-2015 was significantly higher compared with the strains isolated during 2008-2010. Further study showed that the correlation between phenotypic and genotypic resistance varied among the isolates from different sources, and in many cases, the presence of resistance genes was not consistent with the resistance to the corresponding antimicrobials. These results are very significant for veterinary practice and public health.

Topics: Animal Husbandry; Animals; Anti-Bacterial Agents; Cefotaxime; China; Ciprofloxacin; Drug Resistance, Multiple, Bacterial; Farms; Genotype; Phenotype; Salmonella; Salmonella Infections, Animal; Serogroup; Swine; Swine Diseases; Tetracycline

In 2013-2014, 201 pigs belonging to 67 batches were tested for Salmonella in their mesenteric lymph nodes (MLN) in one abattoir of Northern Italy. For each batch, faecal material was collected at lairage by swabbing the pen floor for approximately 1600 cm(2). The aim of this study was to investigate the prevalence of Salmonella in MLN of pigs at slaughter, to assess Salmonella contamination at lairage and to evaluate the effect of lairage duration on its prevalence. Serotyping, XbaI PFGE typing and antimicrobial testing of the isolates were performed. Pig and human Salmonella isolates of the same region of Italy were compared to evaluate possible correlations. Salmonella enterica was isolated from 19.9% of the MLN and 49.3% of the environmental faecal samples. Nine different serovars were identified among 75 S. enterica isolates. In MLN Salmonella Derby was the most common (52.5%), followed by S. enterica 4,[5],12:i:- (17.5%) and Salmonella Rissen (10.0%). In faecal samples S. Derby was prevalent (51.4%), followed by S. enterica 4,[5], 12:i:- (20.0%) and Salmonella Brandenburg (14.3%). Lairage holding varied between 1 and ≥ 12 h (median value: 2.5h). In pigs held for 1-3h, 14.1% were positive for Salmonella in MLN but the prevalence reached 31.8% when they were held for ≥ 12 h. The contamination of MLN was statistically different (p=0.0045) between the two groups, thus confirming the role of long-lasting lairage in Salmonella contamination of pigs. XbaI PFGE typing detected 36 PFGE types. Twenty-three PFGE types were identified among the 40 MLN isolates and 22 PFGE types among the 35 faecal isolates. A total of 11 PFGE types were shared between the MLN of pigs and the lairage environment. Among S. Derby, 6 shared PFGE types between MLN and faeces were found and among S. enterica 4,[5],12:i:- one PFGE type was common between MLN and the faecal samples. Shared profiles between human and swine isolates of S. Derby, S. enterica 4,[5],12:i:-, S. Rissen, Salmonella Manhattan, S. Brandenburg, Salmonella Livingstone, Salmonella London and Salmonella Muenchen were identified. Among S. Derby and S. enterica 4,[5],12:i:- isolates found in pigs, 6/15 profiles (40.0%) and 8/10 (80.0%) were shared with human isolates. High resistance rates to streptomycin (97.3%), sulphonamide compounds (84.0%) and tetracycline (56.0%) were observed. No resistance was detected to ertapenem and meropenem. High proportions of isolates showed intermediate sensitivity to ciprofloxacin (85.

Topics: Abattoirs; Animals; Anti-Bacterial Agents; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Feces; Humans; Italy; Lymph Nodes; Meat; Microbial Sensitivity Tests; Prevalence; Salmonella enterica; Salmonella Infections, Animal; Serotyping; Swine; Swine Diseases; Tetracycline

OBJECTIVE To describe the antimicrobial resistance patterns of Salmonella isolates obtained from horses in the northeastern United States and to identify trends in resistance to select antimicrobials over time. SAMPLE 462 Salmonella isolates from horses. PROCEDURES Retrospective data were collected for all Salmonella isolates obtained from equine specimens that were submitted to the Cornell University Animal Health Diagnostic Center between January 1, 2001, and December 31, 2013. Temporal trends in the prevalence of resistant Salmonella isolates were investigated for each of 13 antimicrobials by use of the Cochran-Armitage trend test. RESULTS The prevalence of resistant isolates varied among antimicrobials and ranged from 0% (imipenem) to 51.5% (chloramphenicol). During the observation period, the prevalence of resistant isolates decreased significantly for amoxicillin-clavulanic acid, ampicillin, cefazolin, cefoxitin, ceftiofur, chloramphenicol, and tetracycline and remained negligible for amikacin and enrofloxacin. Of the 337 isolates for which the susceptibility to all 13 antimicrobials was determined, 138 (40.9%) were pansusceptible and 192 (57.0%) were multidrug resistant (resistant to ≥ 3 antimicrobial classes). The most common serovar isolated was Salmonella Newport, and although the annual prevalence of that serovar decreased significantly over time, that decrease had only a minimal effect on the observed antimicrobial resistance trends. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that current antimicrobial use in horses is not promoting the emergence and dissemination of antimicrobial-resistant Salmonella strains in the region served by the laboratory.

Topics: Animals; Anti-Infective Agents; Drug Resistance, Multiple, Bacterial; Enrofloxacin; Fluoroquinolones; Horses; Microbial Sensitivity Tests; New England; Prevalence; Retrospective Studies; Salmonella; Salmonella Infections, Animal; Tetracycline

Antibiotics are among the most frequently prescribed drugs in human and animal medicine. With antibiotic resistance being a serious threat to veterinary and public health, the prudent use of antibiotics receives much attention. Less well known is that incorrect use of antimicrobial agents may also lead to increased bacterial virulence with the potential of a more severe clinical course of infection. Therefore, the aim of this study was to investigate the effect of subtherapeutic doses of tetracyclines on htpG virulence gene expression in Salmonella Typhimurium and on the course of salmonellosis.. Salmonella strains containing an htpG-luxCDABE transcriptional fusion were constructed. Phenotype microarrays and tetracycline treatment were used to investigate their htpG expression. A Salmonella transposon mutant bank was used to identify genes involved in the induction of htpG gene expression. Finally, the in vitro results were linked to the in vivo situation using a Salmonella mouse model.. We demonstrate that subtherapeutic antimicrobial concentrations can exacerbate bacterial infections through direct up-regulation of bacterial virulence factors using Salmonella Typhimurium 112910a phage type 120/ad as a model organism. Phenotype microarrays showed that expression of the Salmonella Typhimurium virulence gene htpG is increased by several tetracycline antimicrobials at values below their MIC, a process that requires intact Salmonella LPS genes. Exposure of experimentally infected DBA/2J mice to subtherapeutic doxycycline concentrations resulted in htpG-mediated exacerbation of Salmonella Typhimurium infection.. These findings show that the Salmonella isolate used in this study can respond to subtherapeutic tetracycline pressure by increasing its virulence and disease severity.

Topics: Animals; Anti-Bacterial Agents; Artificial Gene Fusion; Bacterial Proteins; Disease Models, Animal; DNA Transposable Elements; Doxycycline; Female; Genes, Reporter; Genetic Testing; HSP90 Heat-Shock Proteins; Luciferases; Mice, Inbred DBA; Microarray Analysis; Microbial Sensitivity Tests; Mutagenesis, Insertional; Salmonella Infections, Animal; Salmonella typhimurium; Tetracycline; Virulence; Virulence Factors

Land application of swine manure in commercial hog farms is an integral part of their waste management system which recycles the nutrients back to the soil. However, manure application can lead to the dissemination of bacterial pathogens in the environment and pose a serious public health threat. The aim of this study was to determine the dissemination of antimicrobial resistant Salmonella in the environment due to manure application in commercial swine farms in North Carolina (n = 6) and Iowa (n = 7), two leading pork producing states in the US. We collected manure and soil samples twice on day 0 (before and after manure application) from four distinct plots of lands (5 soil samples/plot) located at 20 feet away from each other in the field. Subsequent soil samples were collected again on days 7, 14, 21 from the same plots. A total of 1,300 soil samples (NC = 600; IA = 700) and 130 manure samples (NC = 60; IA = 70) were collected and analyzed in this study. The overall Salmonella prevalence was 13.22% (189/1,430), represented by 10.69% and 38.46% prevalence in soil and manure, respectively. The prevalence in NC (25.45%) was significantly higher than in IA (2.73%) (P<0.001) and a consistent decrease in Salmonella prevalence was detected from Day 0-Day 21 in all the farms that tested positive. Salmonella serotypes detected in NC were not detected in IA, thereby highlighting serotype association based on manure storage and soil application method used in the two regions. Antimicrobial susceptibility testing was done by the broth microdilution method to a panel of 15 antimicrobial drugs. A high frequency of isolates (58.73%) were multidrug resistant (resistance to three or more class of antimicrobials) and the most frequent resistance was detected against streptomycin (88.36%), sulfisoxazole (67.2%), and tetracycline (57.67%). Genotypic characterization by pulse field gel electrophoresis revealed clonally related Salmonella in both manure and soil at multiple time points in the positive farms. Our study highlights the potential role of swine manure application in the dissemination and persistence of antimicrobial resistant Salmonella in the environment.

Topics: Animals; Anti-Bacterial Agents; Drug Resistance, Multiple, Bacterial; Electrophoresis, Gel, Pulsed-Field; Environment; Manure; Microbial Sensitivity Tests; Phylogeny; Salmonella; Salmonella Infections, Animal; Serogroup; Streptomycin; Sulfisoxazole; Swine; Swine Diseases; Tetracycline

Although cattle movement and commingling play an important role in the inter-herd transmission of pathogens, little is known about the effect of commingling of heifers at raising operations. The objective of this study was to compare the resistance of E. coli and prevalence of Salmonella from pooled faecal pats of heifers raised off-farm at multi-source raisers (MULTI) that raised heifers from at least two farms compared with on-farm raisers (HOME), with heifers from only that farm. MULTI faecal pat samples were collected from pens with animals that had arrived at the farm within the previous 2 months (AP) and from animals that would be departing the heifer raiser in 2-3 months (DP). Corresponding age sampling was conducted at HOME raisers. Odds of ampicillin resistance were 3·0 times greater in E. coli collected from MULTI compared to HOME raisers. E. coli from AP pens had significantly (P < 0·05) higher odds of resistance to ampicillin, neomycin, streptomycin, and tetracycline compared to DP pens. Salmonella recovery was not significantly different between heifer-raising systems (P = 0·3). Heifer-raising system did not have a major overall impact on selection of resistant E. coli, which was strongly affected by the age of the animals sampled.

Topics: Age Factors; Ampicillin; Animal Husbandry; Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; Drug Resistance, Bacterial; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Feces; Microbial Sensitivity Tests; Neomycin; Prevalence; Salmonella; Salmonella Infections, Animal; Streptomycin; Tetracycline

Clinically healthy homing pigeons may serve as an unnoticed reservoir for zoonotic bacteria. Hence, healthy pigeons from 172 different racing pigeon lofts were examined for Salmonella serovars, Campylobacter spp. and Chlamydophila (Chlamydia) psittaci. Two samplings were performed during the racing season in summer (1242 adult and 1164 juvenile pigeons) and two during winter (1074 adult pigeons). Each sampling was accompanied by a questionnaire to identify risk factors for positive lofts. Between 0.9 and 3.7%, 13.1 and 23.7%, and 12.8 and 42.6% of lofts were tested positive by cultural methods or polymerase chain reaction for Salmonella Typhimurium var. Copenhagen, Campylobacter jejuni and C. psittaci, respectively. The detection rate of C. psittaci was twice as high in samples from juvenile pigeons (29.1%) compared with samples from adult pigeons (15.0%, P <0.001). No other influence of age or season was detected. For the first time, pigeon-derived C. jejuni isolates (n=15) were characterized for their ability to invade human enterocytes in vitro. All isolates were invasive with an invasion index between 0.4 and 34.1 (human reference strain: average 11.3). Of 50 C. jejuni isolates tested for antimicrobial susceptibility, 46.0% were resistant to ciprofloxacin. All isolates were sensitive to erythromycin and tetracycline. The analysis of risk factors in association with the infection status of lofts for C. jejuni and C. psittaci suggested that biosecurity measures reduce the risk of infection. This study indicated a zoonotic potential of pigeon-derived C. jejuni. However, clinically healthy homing pigeons pose only a low risk for transmission of the investigated pathogens to humans.

Topics: Adult; Animals; Anti-Bacterial Agents; Bird Diseases; Caco-2 Cells; Campylobacter Infections; Campylobacter jejuni; Chlamydophila psittaci; Ciprofloxacin; Columbidae; Erythromycin; Germany; Humans; Incidence; Male; Phenotype; Psittacosis; Risk Factors; Salmonella Infections, Animal; Salmonella typhimurium; Tetracycline; Zoonoses

The objective of this study was to determine the prevalence of Campylobacter and Salmonella in broilers and their distribution in the indoor and outdoor farm environment. Nine hundred samples (400 faecal; 300 indoor environment; 200 outdoor environment), were collected from 10 individual broiler houses on 10 farms. Campylobacter jejuni prevalence was significantly higher (P=0.003) in faeces (29.5%; 118/400) than the environment (0.8%; 4/500) in contrast to Salmonella Typhimurium from faecal (8.8%; 35/400) and environmental (8.4%; n=42/500) sources (P=0.217). S. Typhimurium predominantly exhibited antimicrobial resistance (AR) to streptomycin (46%) and tetracycline (31.5%). C. jejuni isolates exhibited AR only to tetracycline (55.5%). The PFGE profile revealed 100% similarity between S. Typhimurium isolates from faecal and environmental sources. No relationship was detected between C. jejuni isolates. The low prevalence of Campylobacter and Salmonella in the outdoor environment indicates that it may not be a significant reservoir for transmission of these pathogens on broiler farms.

Topics: Animal Husbandry; Animals; Campylobacter Infections; Campylobacter jejuni; Chickens; Drug Resistance, Microbial; Environmental Microbiology; Feces; Housing, Animal; Microbial Sensitivity Tests; Poultry Diseases; Salmonella Infections, Animal; Salmonella typhimurium; Streptomycin; Tetracycline

The aim of this study was to identify Salmonella serotypes infecting cattle in Pennsylvania, to compare infection rates for the predominant serotype, Salmonella enterica serotype Cerro, with the infection rates for the same serotype in humans, and to study the clonal diversity and antimicrobial resistance for this serotype in cattle from 2005 to 2010. Clonal diversity among the selected isolates was studied using pulsed-field gel electrophoresis (PFGE) and repetitive (rep)-polymerase chain reaction (PCR). Salmonella Cerro showed the single largest increase as a cause of cattle infections over the study period. The proportional distribution of Salmonella Cerro serotype among laboratory-submitted Salmonella positive cases in cattle was 36.1% in the year 2010 compared to 14.3% in 2005. A simultaneous decrease in serotype Newport infections was also observed in cattle (25% in 2005, to 10.1% in 2010). Studies of clonal diversity for cattle and human isolates revealed a predominant PFGE type but showed some variability. All tested isolates (n = 60) were susceptible to sulfamethoxazole-trimethoprim, but 2% of cattle isolates (n = 1/50) and 20% of human isolates (n = 2/10) showed resistance to tetracycline and sulfisoxazole. One human isolate showed additional resistance to ampicillin and gentamicin. This study suggests an increase in Salmonella Cerro infections in the cattle population and a decrease in Salmonella Newport infections. The increase in Cerro infections appears to be restricted to the cattle population, but occasional human infections occur.

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; DNA Fingerprinting; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Electrophoresis, Gel, Pulsed-Field; Gentamicins; Humans; Laboratories; Pennsylvania; Polymerase Chain Reaction; Prevalence; Salmonella enterica; Salmonella Infections; Salmonella Infections, Animal; Serotyping; Sulfisoxazole; Tetracycline

To detect antimicrobial resistance genes in Salmonella isolates from turkey flocks using the microarray technology.. A 775 gene probe oligonucleotide microarray was used to detect antimicrobial resistance genes in 34 isolates. All tetracycline-resistant Salmonella harboured tet(A), tet(C) or tet(R), with the exception of one Salmonella serotype Heidelberg isolate. The sul1 gene was detected in 11 of 16 sulfisoxazole-resistant isolates. The aadA, aadA1, aadA2, strA or strB genes were found in aminoglycoside-resistant isolates of Salm. Heidelberg, Salmonella serotype Senftenberg and untypeable Salmonella. The prevalence of mobile genetic elements, such as class I integron and transposon genes, in drug-resistant Salmonella isolates suggested that these elements may contribute to the dissemination of antimicrobial resistance genes in the preharvest poultry environment. Hierarchical clustering analysis demonstrated a close relationship between drug-resistant phenotypes and the corresponding antimicrobial resistance gene profiles.. Salmonella serotypes isolated from the poultry environment carry multiple genes that can render them resistant to several antimicrobials used in poultry and humans.. Multiple antimicrobial resistance genes in environmental Salmonella isolates could be identified efficiently by microarray analysis. Hierarchical clustering analysis of the data was also found to be a useful tool for analysing emerging patterns of drug resistance.

Topics: Animals; Anti-Bacterial Agents; Cluster Analysis; DNA Probes; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Environmental Microbiology; Microbial Sensitivity Tests; Oligonucleotide Array Sequence Analysis; Poultry Diseases; Salmonella enterica; Salmonella Infections, Animal; Serotyping; Tetracycline; Turkeys

PR-39 is a porcine antimicrobial peptide that kills bacteria with a mechanism that does not involve cell lysis. Here, we demonstrate that Salmonella enterica serovar Typhimurium can rapidly acquire mutations that reduce susceptibility to PR-39. Resistant mutants appeared at a rate of 0.4 x 10(-6) per cell per generation. These mutants were about four times more resistant than the wild type and showed a greatly reduced rate of killing. Genetic analysis revealed mutations in the putative transport protein SbmA as being responsible for the observed resistance. These sbmA mutants were as fit as the wild-type parental strain as measured by growth rates in culture medium and mice and by long-term survival in stationary phase. These results suggest that resistance to certain antimicrobial peptides can rapidly develop without an obvious fitness cost for the bacteria and that resistance development could become a threat to the efficacy of antimicrobial peptides if used in a clinical setting.

Topics: Animals; Anti-Bacterial Agents; Antimicrobial Cationic Peptides; Bacterial Proteins; Cathelicidins; Drug Resistance, Multiple, Bacterial; Female; Genetic Complementation Test; Mice; Mice, Inbred BALB C; Microbial Sensitivity Tests; Models, Genetic; Mutagenesis, Insertional; Mutation; Salmonella Infections, Animal; Salmonella typhimurium; Sequence Deletion

Salmonella enterica serovar Heidelberg strains are frequently associated with food-borne illness, with recent isolates showing higher rates of resistance to multiple antimicrobial agents. One hundred eighty S. enterica serovar Heidelberg isolates, collected from turkey-associated production and processing sources, were tested for antimicrobial susceptibility and compared by pulsed-field gel electrophoresis (PFGE) and plasmid profile analysis. The potential for the transfer of resistance between strains was studied by conjugation experiments. PFGE analysis using XbaI digestion identified eight clusters (based on 90% similarity), with the largest containing 71% of the isolates. Forty-two percent of the isolates were resistant to at least 1 of the 15 antimicrobial agents tested, and 4% of the isolates were resistant to 8 or more antimicrobial agents. Resistances to streptomycin (32%), tetracycline (30%), and kanamycin (24%) were most commonly detected. Interestingly, the XbaI PFGE profiles of selective multidrug-resistant strains (n = 22) of S. enterica serovar Heidelberg from turkey-associated sources were indistinguishable from the predominant profile (JF6X01.0022) detected in isolates associated with human infections. These isolates were further differentiated into seven distinct profiles following digestion with the BlnI enzyme, with the largest cluster comprising 15 isolates from veterinary diagnostic and turkey processing environments. Conjugation experiments indicated that resistance to multiple antimicrobial agents was transferable among strains with diverse PFGE profiles.

Topics: Animals; Bacterial Typing Techniques; Conjugation, Genetic; Drug Resistance, Multiple, Bacterial; Electrophoresis, Gel, Pulsed-Field; Food Handling; Food Microbiology; Kanamycin; Microbial Sensitivity Tests; Plasmids; Salmonella enterica; Salmonella Infections, Animal; Streptomycin; Tetracycline; Turkeys

The mechanisms involved in fluoroquinolone resistance in Salmonella enterica include target alterations and overexpression of efflux pumps. The present study evaluated the role of known and putative multidrug resistance efflux pumps and mutations in topoisomerase genes among laboratory-selected and naturally occurring fluoroquinolone-resistant Salmonella enterica serovar Typhimurium strains. Strains with ciprofloxacin MICs of 0.25, 4, 32, and 256 microg/ml were derived in vitro using serovar Typhimurium S21. These mutants also showed decreased susceptibility or resistance to many nonfluoroquinolone antimicrobials, including tetracycline, chloramphenicol, and several beta-lactams. The expression of efflux pump genes acrA, acrB, acrE, acrF, emrB, emrD, and mdlB were substantially increased (>or=2-fold) among the fluoroquinolone-resistant mutants. Increased expression was also observed, but to a lesser extent, with three other putative efflux pumps: mdtB (yegN), mdtC (yegO), and emrA among mutants with ciprofloxacin MICs of >or=32 microg/ml. Deletion of acrAB or tolC in S21 and its fluoroquinolone-resistant mutants resulted in increased susceptibility to fluoroquinolones and other tested antimicrobials. In naturally occurring fluoroquinolone-resistant serovar Typhimurium strains, deletion of acrAB or tolC increased fluoroquinolone susceptibility 4-fold, whereas replacement of gyrA double mutations (S83F D87N) with wild-type gyrA increased susceptibility>500-fold. These results indicate that a combination of topoisomerase gene mutations, as well as enhanced antimicrobial efflux, plays a critical role in the development of fluoroquinolone resistance in both laboratory-derived and naturally occurring quinolone-resistant serovar Typhimurium strains.

Topics: Animals; Anti-Infective Agents; DNA Topoisomerases; Drug Resistance, Bacterial; Fluoroquinolones; Gene Targeting; Genes, Bacterial; Mutation; Salmonella Infections, Animal; Salmonella typhimurium

The cardiovascular drug oxyfedrine HCl revealed noteworthy in vitro antibacterial action against 501 strains of Gram positive and Gram negative bacteria. It also offered significant protection to mice challenged with a mouse-virulent bacterial strain. Prompted by such results, the present study was carried out to ascertain whether this drug could augment the efficiency of an antibiotic when used in combination with it. For this purpose, ten bacterial strains were selected, which were sensitive to oxyfedrine as well as to six antibiotics, like benzyl penicillin, chloramphenicol, ciprofloxacin, erythromycin, streptomycin and tetracycline. Distinct and statistically significant (p<0.01) synergism was observed between oxyfedrine and tetracycline by disc diffusion tests, compared with their individual effects. The fractional inhibitory concentration (FIC) index of this combination, evaluated by checkerboard analysis, was 0.37, which confirmed synergism between the pair. This synergistic drug duo was further dispensed to infected mice. The results of the mouse-protection tests advocated that the combination was significantly synergistic (p<0.0001), according to Student's 't' test. Hence, the capacity of extended antibiotic therapy in several microbial diseases may be improved with the help of this synergistic drug pair, and the study might throw light on newer directions to contest drug-resistant bacterial infections.

Topics: Animals; Anti-Bacterial Agents; Bacteria; Drug Synergism; Drug Therapy, Combination; Male; Mice; Microbial Sensitivity Tests; Oxyfedrine; Salmonella Infections, Animal; Salmonella typhimurium; Tetracycline

Salmonella Hadar, Salmonella Brancaster and Salmonella Enteritidis are the main Salmonella enterica ssp. enterica serovars isolated from poultry in Senegal. Our objective was to analyse the pulsed-field gel electrophoresis (PFGE) and antibioresistance patterns of strains belonging to these serovars and to assess the significance of broiler-chicken meat as a source of human infection.. A total of 142 Salmonella isolates were analysed: 79 were isolated from Senegalese patients with sporadic diarrhoea (11 S. Hadar, nine S. Brancaster and 59 S. Enteritidis) and 63 from poultry (30 S. Hadar, 17 S. Brancaster and 16 S. Enteritidis). The PFGE of XbaI- and SpeI-digested chromosomal DNA gave 20 distinct profiles for S. Hadar, nine for S. Brancaster and 22 for S. Enteritidis. Each serovar was characterized by a major pulsotype which was X3S1 in 42% of S. Hadar, X8S1 in 53.8% of S. Brancaster and X1S2 in 43% of S. Enteritidis isolates. Human and poultry isolates of Salmonella had common PFGE patterns. Antibiosensitivity tests showed multiresistance (more than two drugs) was encountered in 14.5% of S. Hadar and in 5% of S. Enteritidis isolates. Resistance to quinolones was considered to be of particular importance and 14.5% of S. Hadar isolates were found to be resistant to nalidixic acid. CONLCUSIONS: The sharing of similar PFGE profiles among isolates from humans and poultry provided indirect evidence of Salmonella transmission from contaminated broiler meat. But most of the Salmonella isolates remained drug sensitive.. Efforts are needed to eliminate Salmonella from poultry meat intended for human consumption. This study has also highlighted the importance of continuous surveillance to monitor antimicrobial resistance in bacteria associated with animals and humans.

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Anti-Infective Agents; Chickens; Chloramphenicol; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Electrophoresis, Gel, Pulsed-Field; Gentamicins; Humans; Nalidixic Acid; Phylogeny; Poultry Diseases; Quinolines; Salmonella enterica; Salmonella enteritidis; Salmonella Infections; Salmonella Infections, Animal; Senegal; Tetracycline; Trimethoprim, Sulfamethoxazole Drug Combination

Two postparturient beef cows in a herd of 30 developed acute enteritis, with pyrexia and bloody diarrhea containing intestinal casts. Salmonella typhimurium phage type 66 was isolated from feces of both animals; both recovered after treatment with tetracycline. A third cow had died without treatment after showing similar signs.

Topics: Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; Feces; Female; Salmonella Infections, Animal; Salmonella typhimurium; Tetracycline

The rectal swabs of diarrhoeic and apparently healthy non-diarrhoeic dogs presented to a Small Animal Clinic were cultured for Escherichia coli, Salmonella and Campylobacter and the enteropathogens were characterized. Overall, of 130 dogs divided equally into two groups consisting of 65 diarrhoeic and 65 non-diarrhoeic dogs, 99 (76.2%), 6 (4.6%) and 18 (13.8%) were positive for E. coli, Salmonella and Campylobacter, respectively. The differences were statistically significant (P < or = 0.05; chi 2). The prevalences of the enteropathogens in diarrhoeic and non-diarrhoeic dogs were not statistically significant (P > or = 0.05; chi 2). Diarrhoea was significantly (P < or = 0.01; chi 2) more prevalent in dogs less than 6 months of age and 7 months to 1 year old than in dogs older than 1 year. The prevalences of Salmonella, E. coli and enteropathogenic E. coli (EPEC) strains were not significantly (P > or = 0.05; chi 2) associated with age but the prevalence of Campylobacter infection was significantly (P < or = 0.01; chi 2) higher in dogs less than 1 year old (25.0%) than in older dogs (5.4%). Of 99 E. coli strains tested, three (3.0%), four (4.0%), five (5.1%) and 20 (20.2%) were haemolytic, non-sorbitol fermenters, verocytotoxigenic (VT) and EPEC strains, respectively. Resistance to tetracycline (59.6%) and ampicillin (50.5%) was most prevalent and significantly (P < or = 0.01; chi 2) higher than to six other antimicrobial agents.

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Campylobacter Infections; Diarrhea; Dog Diseases; Dogs; Drug Resistance, Microbial; Escherichia coli Infections; Female; Male; Penicillins; Prevalence; Salmonella Infections, Animal; Tetracycline; Trinidad and Tobago

Topics: Animals; Anti-Bacterial Agents; Bacterial Typing Techniques; Cattle; Cattle Diseases; Denmark; Drug Resistance, Microbial; Female; Salmonella Infections, Animal; Salmonella typhimurium; Tetracycline; Tetracycline Resistance

A series of experiments was carried out to investigate the efficacy of the competitive exclusion technique in the control of Salmonella in broiler chicks. Anaerobic overnight culture obtained using 10(-3) g ml-1 caecal material in VL-broth medium provided total exclusion of a moderate S. enteritidis challenge (1.2 x 10(2) cells/chick). Increasing the challenge level resulted in less protection, but significant protection occurred at an excessive S. enteritidis challenge level of 1.5 x 10(6) cells/chick. The effectiveness of protection using both moderate and excessive challenges was monitored in newly hatched chicks until they were 22 days old. An improvement in growth performance in terms of higher body weight, feed consumption and feed conversion, in addition to lower mortality, was observed. The use of other control measures such as antimicrobial feed additives or lactose sugar (1.5% w/v) in the drinking water in combination with the competitive microflora treatment resulted in a better overall protection and performance.

Topics: Animals; Anti-Bacterial Agents; Anti-Infective Agents, Local; Bacitracin; Chickens; Poultry Diseases; Salmonella enteritidis; Salmonella Infections, Animal; Tetracycline

Recently, an increased resistance of Campylobacter to fluoroquinolones, a newer class of antimicrobial agents in both human and veterinary medicine, has been reported. Campylobacter isolates (617) from 150 broiler flocks were tested for their susceptibility to cephalothin (control), ampicillin, tetracycline, erythromycin, and the quinolones nalidixic acid, flumequine, enrofloxacin, and ciprofloxacin by a disc diffusion method. Almost complete cross-resistance was found between the quinolones tested. Campylobacter isolates (181, 29%), originating from 55 flocks (37%), were quinolone resistant. Salmonella isolates (94) from 40 flocks were also tested for their antimicrobial susceptibility. Eight isolates (8.5%), from three broiler flocks (7.5%), showed resistance to nalidixic acid and flumequine (and tetracycline), but not to ciprofloxacin or enrofloxacin.

Topics: 4-Quinolones; Ampicillin; Animals; Anti-Bacterial Agents; Anti-Infective Agents; Campylobacter; Campylobacter Infections; Chickens; Erythromycin; Microbial Sensitivity Tests; Netherlands; Poultry Diseases; Salmonella; Salmonella Infections, Animal; Tetracycline

One-half of pituitary-intact or sham-operated rats survive infection with 10(9) colony-forming units of Salmonella typhimurium, whereas rats without a pituitary gland all die within a few days. When the dose of S. typhimurium is reduced 600-fold, 15-25% of the hypophysectomized rats survive, and the survival rate is significantly enhanced by administration of tetracycline, recombinant interferon gamma (IFN-gamma), or recombinant growth hormone (GH). The protective effect of GH is abolished by heat inactivation or with an antibody to GH. Spleens from normal and hypophysectomized rats treated with tetracycline, IFN-gamma, or GH have 59-99% fewer bacteria 5 days after infection as compared to control rats. Peritoneal macrophages from hypophysectomized rats that are infected in vitro with S. typhimurium kill half as many extracellular bacteria as compared to pituitary-intact rats, and this bactericidal capacity is significantly augmented 75-95% by either GH or IFN-gamma. These data establish that the pituitary gland is essential for homeostasis during an infectious episode and that GH plays an important role in host resistance by augmenting the ability of macrophages to kill S. typhimurium.

Topics: Animals; Female; Growth Hormone; Hypophysectomy; Immunity, Innate; Interferon-gamma; Macrophages; Pituitary Gland; Rats; Rats, Inbred Strains; Recombinant Proteins; Salmonella Infections, Animal; Salmonella typhimurium; Tetracycline

Two plasmids which express either nearly intact or truncated filamentous hemagglutinin (FHA) from Bordetella pertussis and which are marked with a tetracycline resistance (Tcr) gene were transformed into Salmonella dublin SL1438, an aroA deletion mutant intended for use as an attenuated oral vaccine against salmonellosis. These S. dublin recombinants, when fed to mice, induced serum immunoglobulin, immunoglobulin M (IgM), and sometimes IgA antibody responses to FHA and S. dublin. In addition, IgA antibodies against FHA were found in gut wash fluids. S. dublin carrying pDB2300, a multicopy plasmid encoding truncated FHA protein, induced a better antibody response than did S. dublin carrying pDB2000, a low-copy-number plasmid encoding full-sized FHA. Administration of tetracycline to mice enhanced the stability of recombinant plasmids, and tetracycline-treated mice developed higher anti-FHA titers. Although neither strain examined is suitable for use in a human oral vaccine, these data demonstrated that an immune response against B. pertussis FHA could be induced by oral administration of live attenuated recombinant strains of S. dublin and suggested that development of a live oral attenuated vaccine against pertussis may be possible.

Topics: Animals; Antibodies, Bacterial; Bacterial Vaccines; Bordetella pertussis; Chromosome Deletion; Female; Gene Expression; Hemagglutinins; Male; Mice; Mice, Inbred BALB C; Plasmids; Salmonella; Salmonella Infections, Animal; Tetracycline; Vaccines; Vaccines, Attenuated; Vaccines, Synthetic

The number of viable cells of two strains of Salmonella typhimurium and the number of viable cells and the cell size of the colon microbiota of mice were examined during non-growing conditions after exposure to antibiotics with known modes of action. Salmonella typhimurium starved for 1, 2, 4, 5, 12 and 20 d in a phosphate buffer saline solution and subsequently exposed for 2 and 6 h showed the following characteristics. The protein synthesis inhibitors gentamicin and tetracycline, the RNA synthesis inhibitor rifampicin and the membrane potential inhibitor polymyxin all impaired survival of starved cells. The reduction in the number of viable cells caused by the addition of gentamicin, rifampicin and polymyxin was generally more pronounced with extended exposure to energy and nutrient deprivation. Both 2- and 6-h exposure of tetracycline, however, had diminishing inhibitory effects after 20 d compared with 5 d of starvation. Control experiments to verify non-growing conditions in the starvation regime showed that DNA and cell wall synthesis inhibitors had no inhibitory effect after 24-h starvation. The rough mutant strain displayed a lower sensitivity to a hydrophobic rather than a hydrophilic inhibitor as compared to the smooth wild-type strain. The cell size reduction but not viability was partly prevented by protein synthesis inhibitors as seen for both in vivo and in vitro colon microbiota studies.

Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; Cell Wall; Colon; Colony Count, Microbial; Food Deprivation; Gentamicins; Lactams; Mice; Mice, Inbred BALB C; Nalidixic Acid; Polymyxins; Rifampin; RNA, Bacterial; Salmonella Infections, Animal; Salmonella typhimurium; Tetracycline

The transmission of pathogenic bacteria from animals to humans is widely studied because of its public health importance. In this study, we show the transmission of Salmonella typhimurium from cattle which had received no growth-promoting antibiotics to humans who had direct contact with the ill animals. On one cattle farm, the veterinarian attending the sick animals became ill, and two other individuals living on the farm later developed salmonellosis. The strains isolated from both humans and animals at one farm were identical as to antibiotic susceptibility and phage type, and they were specifically traced by the presence of a common 24-megadalton plasmid. Restriction enzyme digests of this plasmid from both human and animal strains were identical. At another farm, tetracycline-resistant S. typhimurium strains possessing a different profile (eight plasmids) were isolated from both animals and humans. The tetracycline-resistant clone was also isolated from animals at a third farm, but with animals and humans having no known contact with those of the other two farms.

Topics: Animals; Bacteriophage Typing; Cattle; Cattle Diseases; Cloning, Molecular; Conjugation, Genetic; DNA, Bacterial; Drug Resistance, Microbial; Humans; Norway; Plasmids; Salmonella Infections; Salmonella Infections, Animal; Salmonella typhimurium; Tetracycline

A virulent Salmonella dublin isolate was made histidine-requiring (his-) to allow recognition. The his- derivative, SL1367 (still calf-virulent), was then given by transduction and mutation, a transposon-generated non-reverting aromatic biosynthesis (aro) defect; this defect caused loss of virulence for the mouse. The his- aro- derivative strain, SL1438, was effective as a live vaccine in mice. Twenty male Holstein calves were divided into 4 groups. Groups I, II, and III were vaccinated IM at 2 weeks and at 3 weeks of age with aromatic-dependent (aro-) S dublin strain SL1438. Groups I and III received freshly prepared vaccine and group II received lyophilized vaccine. Serious adverse reactions to the vaccination were not seen. After vaccination, the mean maximum increase in rectal temperature was 1.8 C in group I and III calves and 0.6 C in group II calves. Fewer group II calves developed diarrhea (1 of 5) or positive blood cultures (0 of 5) after vaccination compared with group I and III calves (6 of 10 and 5 of 10, respectively). Postvaccination diarrhea was mild and of short duration. Group IV was comprised of 5 nonvaccinated calves. At 5 weeks of age, all calves were challenge exposed orally. Group I, II, and IV calves were challenge exposed with 10(11) virulent S dublin SL1367. Group III was challenge exposed with 10(11) virulent S typhimurium UCD 108-11. Subsequently, fever and diarrhea (lasting 1 to 3 days), but no deaths, were observed in the vaccinated calves. Four of the 5 nonvaccinated (group IV) calves died (P less than 0.001) within 8 days after challenge exposure. Aro- S dublin SL 1438 did not cause serious adverse effects and provided protection against oral challenge exposure with either virulent S dublin or S typhimurium.

Topics: Animals; Bacterial Vaccines; Cattle; Cattle Diseases; Drug Resistance, Microbial; Histidine; Male; Mutation; Salmonella; Salmonella Infections, Animal; Salmonella typhimurium; Tetracycline; Vaccines, Attenuated; Virulence

A natural outbreak of Salmonella saint-paul infection in two Institute herds was monitored clinically, bacteriologically and immunologically. This paper describes the findings in calves. Morbidity and mortality became apparent 30 days after S. saint-paul was first isolated on routine sampling of neonatal calf faeces. All heifer calves were treated with a tetracycline or ampicillin preparation when they showed clinical signs of disease, while the effects of intradermal vaccination with heat-killed S. saint-paul were assessed in a proportion of the bull calves. Antibiotic treatment reduced mortality and the number of persistent excretors; vaccination did not affect mortality but, if given during the first week of life, reduced the duration of faecal excretion. Calves which were untreated and unvaccinated, or vaccinated when older than 16 days, excreted S. saint-paul for periods of up to 18 months. Of six 'recovered' calves, which had been negative on faecal culture for 5-8 weeks, four yielded S. saint-paul at necropsy. Agglutinating antibody titres were highest in those unvaccinated calves which were persistent excretors.

Topics: Ampicillin; Animals; Animals, Newborn; Cattle; Cattle Diseases; Disease Outbreaks; England; Feces; Salmonella; Salmonella Infections, Animal; Tetracycline

Weanling pigs in groups of 12 were infected orally with Salmonella choleraesuis and were treated intramuscularly with doses of cephamycin C ranging from 12.5 to 337.5 mg twice daily for 10 days beginning 1 day postinoculation. Pigs in two other infected groups either received 300 mg of tetracycline orally on a similar schedule or served as nonmedicated controls. Optimal responses to cephamycin C were achieved at a twice daily dose of 112.5 mg. With this regimen, the febrile response was significantly reduced on day 2 and eliminated by day 5 postinfection, and the shedding of Salmonella spp. in feces was eliminated by day 5 postinfection; essentially, no lesions were found in the gastrointestinal tract at necropsy (day 26 postinfection). There was no mortality among recipients of the 112.5-mg dose; diarrhea was present on only 2% of the observation days. In contrast, 83% of the infected, nonmedicated pigs and 25% of the tetracycline-medicated pigs died, and diarrhea was present in these groups on 63 and 54% of the observation days, respectively. The striking benefits of cephamycin C treatment was achieved without adverse reactions. The weight gain and feed efficiency of the infected pigs treated with the 112.5-mg dose of cephamycin C and the noninfected, nonmedicated control pigs were equivalent.

Topics: Animals; Cephalosporins; Cephamycins; Feces; Female; Male; Salmonella Infections, Animal; Swine; Swine Diseases; Tetracycline

Topics: Animals; Animals, Laboratory; Disease Outbreaks; Enteritis; Feces; Female; Formaldehyde; Fumigation; Housing, Animal; Male; Mice; Mice, Inbred CBA; Rodent Diseases; Salmonella; Salmonella Infections, Animal; Tetracycline

A Salmonella heidelberg epidemic in a hospital nursery was traced to infected calves on a dairy farm where the mother of the index patient lived. The Salmonella isolates from all cases were resistant to chloramphenicol, sulfamethoxazole, and tetracycline. Verification of the spread of infection from the farm animals to a hospital population is unusual and raises questions about the hazards of antibiotic animal-feed preparations that may induce infection with resistant organisms in humans.

Topics: Animals; Cattle; Cattle Diseases; Chloramphenicol; Connecticut; Cross Infection; Disease Outbreaks; Drug Resistance, Microbial; Female; Humans; Infant, Newborn; Infant, Newborn, Diseases; Male; Nurseries, Hospital; Pregnancy; Salmonella; Salmonella Infections; Salmonella Infections, Animal; Sulfamethoxazole; Tetracycline; Zoonoses

Only 12% of 249 strains of Salmonella typhimurium isolated during the period 1973-1976 from diseased animals were sensitive to six commonly used antibiotics. Isolates from calves exhibited the highest frequency of resistance as well as a steadily increasing frequency of resistance to ampicillin and chloramphenicol. The majority of strains from horses, dogs, and cats were also resistant to more than one antibiotic, a finding which was interpreted as primarily an effect of therapeutic rather than of growth-promoting use of antibiotics in these species. Ninety-one percent of resistant strains possessed transferable resistance. In 31% of these strains, the transfer factors were heat-sensitive and did not function at 37 C. The determinant of resistance to ampicillin was usually associated with a non-heat-sensitive transfer factor, whereas resistance to chloramphenicol, kanamycin, and tetracycline was more commonly associated with heat-sensitive transfer factors. Strains of S. typhimurium with similar patterns of resistance often contained different plasmids. There was more genetic homogeneity among determinants of resistance to tetracycline than among other determinants.

Topics: Ampicillin; Animals; Cats; Cattle; Chloramphenicol; Dogs; Horses; Kanamycin; Microbial Sensitivity Tests; Neomycin; New York; Salmonella Infections, Animal; Salmonella typhimurium; Streptomycin; Swine; Tetracycline

The resistance of Salmonellae to drugs has been studied in the Netherlands since 1958. In 1972, 1973, and 1974 respectively, 14241, 13086, and 22927 strains were tested for resistance to ampicillin, chloramphenicol, kanamycin and tetracycline. From 1973 all strains were also tested for resistance to trimethoprim. In the period covered, the yearly incidence of resistance to at least one of the above drugs ranged from 39.2% to 45.6% of all strains obtained from various sources (humans, animals, animal products, sewage, etc.). A new finding in the period 1972 to 1974 was that many multiply resistant strains emerged in S. typhimurium and in S. dublin isolated from calves and cattle. In 1974, 64.4% of all strains of S. typhimurium from these animals appeared to be resistant to ampicillin, tetracycline, chloramphenicol and kanamycin, and 25.5% of those of S. dublin were found to be resistant to chloramphenicol and tetracycline. Of all strains of Salmonellae examined in 1973 and 1974 respectively, 0.15% and 0.22% were resistant to trimethoprim, the main component of the twin-drug cotrimoxazol. Of the 142 strains of S. typhi isolated in 1972 to 1974 two were resistant to tetracycline only, and one was resistant to all four antibiotics. The others had a normal susceptibility pattern.

Topics: Ampicillin; Animals; Chloramphenicol; Humans; Kanamycin; Netherlands; Penicillin Resistance; Salmonella; Salmonella Infections; Salmonella Infections, Animal; Tetracycline

Typing of R factors by genetic properties was done with Salmonella typhimurium and Escherichia coli isolated from calves on a feedlot where epizootics of clinical or subclinical calf salmonellosis had repeatedly occurred during 5 years. Forty-nine R factors from S typhimurium were fi- (no fertility inhibition) and spp- (no restriction against phage lambda vir). Twenty-three (46.9%) of them belonged to compatibility group Ialpha and the remainder were nontypable. Fourteen R factors from E coli belonged to different genetic types: fi+ (11=78.6%) and fi- (3=21.4%); spp+ (1=7.1%) and spp- (13=92.9%); compatibility groups FII (5=35.7%), N (1=7.1%), and nontypable (8=57.2%). In contrast to the R factors of S typhimurium, 9 (64.3%) of the 14 R factors of E coli carried resistance against aminobenzyl penicillin with or without kanamycin resistance. The compatibility groups of R factors of S typhimurium seemed to be useful as a subsidiary epizootiologic marker in this feedlot.

Topics: Ampicillin; Animals; Cattle; Cattle Diseases; Chloramphenicol; Escherichia coli; Escherichia coli Infections; Kanamycin; Male; Penicillin Resistance; R Factors; Salmonella Infections, Animal; Salmonella typhimurium; Tetracycline

505 out of 1369 S. panama strains isolated mainly from animals, foods, and feedstuffs from 1969 to 1975 were phage-typed. 41% (= 207) of the S. panama isolates examined originated from swine, 26% from cattle and calves, 15% from dogs, and 13% were from other animal species and materials. 465 strains (=92%) showed typical reactions. 23% were specified as phage-type A, 24% as phage-type B and 36% as phage-type G. Phage-types D, E, and F did not occur. In swine, being the most frequent carriers of S. panama, phage-types A, B, and G had nearly the same shares. In dogs, phage-type G predominated to which nearly one half of the examined S. panama isolates from this species belonged. 205 (=41%) out of 505 strains examined for their resistance to antibiotics proved to be tetracycline-resistant. All 123 strains of phage-type B were tetracycline-resistant, all 35 strains of phage-type C were tetracycline-sensitive. 5 strains of phage-type A exhibited transferable tetracycline-resistance determinants.

Topics: Animals; Bacteriophage Typing; Drug Resistance, Microbial; Food Microbiology; Germany, West; Salmonella; Salmonella Infections, Animal; Tetracycline

2273 Salmonella strains received from veterinary laboratories in the Federal Republic of Germany including Berlin (West) in 1972 were examined for their resistance against tetracyclines, ampicillin, chloramphenicol, kanamycin, nitrofurazone, and furazolidone. 13.3% of the strains studied were found to be resistant to one or more of these antibacterial substances. The proportion of resistant strains was 37.5% for S. typhimurium (excluding var. copenhagen), 3.1% for S. typhimurium var. copenhagen and 57% for S. panama. 79.8% of resistant strains were found to belong to these types. From 303 resistant strains found, resistance determinants were present in 87.4% to tetracyclines, in 37.2% to ampicillin, in 15.8% to chloramphenicol, in 4.6% to kanamycin, in 0.9% to furazolidone, and in 1.3% to nitrofurazone. 16 combinations of resistance determinants were found to occur 95.0% of strains transmitted resistance to E. coli K-12. A transmission of resistance determinants to furazolidone and nitrofurazone could not be demonstrated. Resistance patterns differed considerably from one serotype to another.

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Berlin; Chloramphenicol; Furazolidone; Germany, West; Kanamycin; Nitrofurazone; R Factors; Salmonella; Salmonella Infections, Animal; Serotyping; Tetracycline

2894 salmonella strains received from veterinary laboratories in the Federal Republic of Germany including Berlin (West) in 1973 were examined for their resistance against tetracyclines, ampicillin, chloramphenicol, kanamycin, nitrofurazone, and furazolidone. 24.4% of the strains studied were found to be resistant to one or more of these antibacterial substances. The proportion of resistant strains was 63.9% for S. typhimurium (excluding var. copenhagen), 6.5% for S. typhimurium var. copenhagen and 51% for S. panama. 81.3% of resistant strains were found to belong to these types. From 708 resistant strains found, resistance determinants were present in 92.9% to tetracyclines in 27.9% to ampicillin, in 22.0% to chloramphenicol, in 13.6% to kanamycin, in 1.4% to furazolidone, and in 1.7% to nitrofurazone. 20 combinations of resistance determinants were found to occur 90.9% of strains transmitted resistance to E. coli K-12. A transmission of resistance determinants to furazolidone and nitrofurazone could not be demonstrated. As in the preceding years, there was a clear difference of resistance patterns from one serotype to another.

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Berlin; Chloramphenicol; Furazolidone; Germany, West; Kanamycin; Nitrofurazone; R Factors; Salmonella; Salmonella Infections, Animal; Serotyping; Tetracycline

Topics: Animals; Animals, Newborn; Anti-Bacterial Agents; Arthritis, Infectious; Cattle; Cattle Diseases; Cystitis; Diarrhea; Escherichia coli Infections; Female; Foot Diseases; Fusobacterium Infections; Liver Abscess; Mastitis, Bovine; Meningitis; Osteomyelitis; Pasteurella Infections; Pneumonia; Respiratory Tract Infections; Salmonella Infections, Animal; Sheep; Sheep Diseases; Streptococcal Infections; Sulfonamides; Tetracycline; Uterine Diseases

Topics: Animals; Carrier State; Diarrhea; Feces; Female; Horse Diseases; Horses; Intestines; Male; Postoperative Complications; Salmonella Infections, Animal; Salmonella typhimurium; Stress, Physiological; Tetracycline

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; Chickens; Chloramphenicol; Drug Resistance, Microbial; Escherichia coli; Extrachromosomal Inheritance; Feces; Furazolidone; Humans; Intestines; Oxytetracycline; Poultry Diseases; Public Health; R Factors; Salmonella; Salmonella Infections; Salmonella Infections, Animal; Salmonella Phages; Salmonella typhimurium; Shigella; Swine; Tetracycline

Chloramphenicol (CP)-resistant Salmonella typhimurium var copenhagen was frequently isolated (44.1 to 76.7%) from dead, diseased, and healthy calves on 3 farms in 1973 in northern Japan. On 2 of the farms, CP-resistant salmonella appeared suddenly during an epizootic of salmonella infection, and persisted. Of 87 CP-resistant to tetracycline (TC), streptomycin (SM), and sulfonamides (SA), and the remaining 13 isolates from dead calves on a farm were resistant to TC, SM, SA, and kanamycin (KM). Resistance patterns of all CP-resistant isolates were transferred completely.

Topics: Animals; Cattle; Cattle Diseases; Chloramphenicol; Culture Media; Drug Resistance, Microbial; Escherichia coli; Feces; Japan; Kanamycin; Liver; Lymph Nodes; R Factors; Salmonella Infections, Animal; Salmonella typhimurium; Streptomycin; Sulfonamides; Tetracycline

Topics: Animals; Bacitracin; Cecum; Chickens; Diet; Food Additives; Intestines; Poultry Diseases; Salmonella; Salmonella Infections, Animal; Tetracycline; Zinc

Topics: Animals; Carrier State; Cattle; Cattle Diseases; Drug Resistance, Microbial; Extrachromosomal Inheritance; Rectum; Salmonella Infections, Animal; Salmonella typhimurium; Tetracycline

Topics: Administration, Oral; Animal Feed; Animals; Cecum; Chickens; Crop, Avian; Female; Intestine, Small; Male; Poultry Diseases; Salmonella; Salmonella Infections, Animal; Tetracycline

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Berlin; Chloramphenicol; Food Microbiology; Furazolidone; Germany, West; Kanamycin; Microbial Sensitivity Tests; Nitrofurazone; Penicillin Resistance; Salmonella; Salmonella Infections, Animal; Salmonella typhimurium; Serotyping; Species Specificity; Streptomycin; Sulfonamides; Tetracycline; Water Microbiology

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Berlin; Chloramphenicol; Food Microbiology; Furazolidone; Germany, West; Kanamycin; Microbial Sensitivity Tests; Nitrofurazone; Penicillin Resistance; Salmonella; Salmonella Infections, Animal; Salmonella typhimurium; Serotyping; Species Specificity; Tetracycline; Water Microbiology

The effect of chlortetracycline fed at concentrations of 10 or 20 grams per ton on the antibiotic resistance of fecal coliforms from weaned pigs from four different farms was studied. At admission to experimental quarters, coliforms resistant to at least one antibiotic predominated in all groups of animals. In pigs from three farms, chlortetracycline caused a reduction in the proportion of sensitive coliforms excreted, the extent of reduction depending on feeding practices on the farm of origin. In another experiment using pigs from a fourth farm, almost all coliforms isolated were resistant. Of all resistant strains isolated, those carrying resistance to a multiplicity of antibiotics predominated, and resistance to tracycline unaccompanied by that to other agents was relatively infrequent. Special studies of hemolytic coliforms from pigs from one farm identified two particular antibiotic sensitive types. No further isolations of these types were made once chlortetracycline administration began although 21 additional isolates were made from littermates receiving unsupplemented ration. These findings suggest that the elimination of sensitive strains resulting from chlortetracycline administration was due to a replacement of these strains by different resistant types rather than by acquisition of resistance by previously sensitive strains.

Topics: Administration, Oral; Animal Feed; Animals; Chlortetracycline; Drug Resistance, Microbial; Escherichia coli; Feces; Microbial Sensitivity Tests; Rectum; Salmonella Infections, Animal; Streptomycin; Swine; Swine Diseases; Tetracycline

Topics: Ampicillin; Animals; Animals, Domestic; Chloramphenicol; Humans; Kanamycin; Microbial Sensitivity Tests; Netherlands; Penicillin Resistance; Salmonella; Salmonella Infections; Salmonella Infections, Animal; Species Specificity; Tetracycline

Topics: Ampicillin; Animals; Cecum; Chickens; Chloramphenicol; Escherichia coli; Extrachromosomal Inheritance; Male; Nalidixic Acid; Neomycin; Penicillin Resistance; Salmonella Infections, Animal; Salmonella typhimurium; Streptomycin; Sulfonamides; Tetracycline; Virulence

Topics: Animals; Anti-Bacterial Agents; Cattle; Dogs; Microbial Sensitivity Tests; Salmonella; Salmonella Infections, Animal; Sheep; Streptomycin; Sudan; Tetracycline

Topics: Animals; Anti-Bacterial Agents; Drug Resistance, Microbial; Salmonella; Salmonella Infections, Animal; Swine; Swine Diseases; Tetracycline

Topics: Ampicillin; Animal Feed; Animals; Animals, Domestic; Anti-Bacterial Agents; Carrier State; Chloramphenicol; Escherichia coli; Escherichia coli Infections; Food Microbiology; Kanamycin; Legislation, Drug; Microbial Sensitivity Tests; Netherlands; Penicillin Resistance; Salmonella; Salmonella Infections, Animal; Salmonella typhimurium; Serotyping; Tetracycline

Topics: Administration, Oral; Animals; Drug Synergism; Edetic Acid; Escherichia coli Infections; Injections, Subcutaneous; Mice; Penicillin G; Salmonella Infections, Animal; Streptococcal Infections; Tetracycline

Salmonella cultures were obtained from outbreaks of animal disease from 37 states and 1 territory. They were screened for resistance to 11 antimicrobial drugs. Of the 1,251 strains studied, 935 were resistant to one or more of these agents. The three most common resistance patterns were ampicillin, dihydrostreptomycin, sulfamethoxypyridazine, tetracycline; ampicillin, dihydrostreptomycin, sulfamethoxypyridazine; dihydrostreptomycin, sulfamethoxypyridazine, tetracycline. Resistance transfer was demonstrated on 267 multiply resistant cultures, of which 181 were able to transfer all or part of their resistance pattern to a drug-sensitive recipient.

Topics: Ampicillin; Animals; Animals, Domestic; Anti-Bacterial Agents; Cats; Cattle; Chickens; Columbidae; Dihydrostreptomycin Sulfate; Dogs; Drug Synergism; Ducks; Geese; Genetics, Microbial; Horses; Microbial Sensitivity Tests; Penicillin Resistance; Salmonella; Salmonella Infections, Animal; Serotyping; Sheep; Species Specificity; Streptomycin; Sulfamethoxypyridazine; Swine; Tetracycline; Turkeys; United States

Topics: Animals; Bird Diseases; Birds; Chloramphenicol; Disease Reservoirs; Drug Resistance, Microbial; Feces; Germany, West; Humans; Psittaciformes; Salmonella Infections; Salmonella Infections, Animal; Salmonella typhimurium; Tetracycline

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Australia; Cattle; Cattle Diseases; Chloramphenicol; Furazolidone; Microbial Sensitivity Tests; Penicillin Resistance; Salmonella; Salmonella Infections, Animal; Streptomycin; Swine; Swine Diseases; Tetracycline

Topics: Animals; Chickens; Drug Resistance, Microbial; Ducks; Poultry Diseases; Salmonella; Salmonella Infections, Animal; Streptomycin; Sulfonamides; Tetracycline; Turkeys

From 1964 to 1967, 6,646 monkeys, representing 10 primate species, were examined for Shigella and Salmonella infections upon arrival at the National Center for Primate Biology. Of these animals, 12% were infected with Shigella, and 75% of the Shigella isolates were S. flexneri 4. The incidence of Salmonella infections decreased from 12 to 3% during the period of study. Epidemiological studies of animals in the colony for 90 days or more indicated no seasonal variation in the occurrence of Shigella and Salmonella. Many of the isolates from incoming monkeys as well as from laboratory-conditioned animals were resistant to chloramphenicol, dihydrostreptomycin, and tetracycline. The possible operation of drug-resistance factors in these infections is discussed.

Topics: Animals; Chloramphenicol; Dihydrostreptomycin Sulfate; Drug Resistance, Microbial; Dysentery, Bacillary; Monkey Diseases; Neomycin; Salmonella; Salmonella Infections, Animal; Seasons; Shigella; Tetracycline

Topics: Age Factors; Animal Diseases; Animals; Bronchopneumonia; Cattle; Chickens; Chlortetracycline; Delayed-Action Preparations; Ducks; Pasteurella Infections; Poultry Diseases; Rhinitis, Atrophic; Salmonella Infections, Animal; Swine; Swine Diseases; Tetracycline

A rise in Salmonella typhimurium infection was observed in calves in Britain during 1964-6, follwing the adoption of the intensive farming method. A single phage type of S. typhimurium, type 29, was incriminated as the major pathogen. Attempts to treat and control the disease with a range of antibiotics were ineffective, but resulted in the acquisition of transferable multiple drug resistance by type 29. The transmission of drug-resistant type 29, directly or indirectly, from bovines to man resulted in many human infections. Transferable drug resistance reaching man from enterobacteria of animal origin may ultimately enter specifically human pathogens. Infections such as that caused by type 29 can be eliminated, not by the massive use of antibiotics but by improvement in conditions of animal husbandry and reduction in the opportunities for the initiation and spread of the disease. A reappraisal is needed of the methods of using antibiotics to determine how these methods can be improved, in order to conserve the long-term efficacy of the antibiotics.

Topics: Ampicillin; Animals; Animals, Newborn; Anti-Bacterial Agents; Bacteriophage Typing; Cattle; Cattle Diseases; Chloramphenicol; Costs and Cost Analysis; Enterobacteriaceae Infections; Furazolidone; Gastroenteritis; Humans; Kanamycin; Neomycin; Penicillin Resistance; Salmonella Infections, Animal; Salmonella typhimurium; Streptomycin; Sulfonamides; Tetracycline; United Kingdom; Vaccination

Topics: Ampicillin; Animals; Cattle; Escherichia coli; Mice; Neomycin; Penicillin Resistance; Polymyxins; Salmonella; Salmonella Infections, Animal; Streptomycin; Swine; Tetracycline; Vaccination

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; Disease Outbreaks; Escherichia coli; Genetics, Microbial; Humans; Penicillin Resistance; Salmonella Infections, Animal; Salmonella typhimurium; Streptomycin; Sulfonamides; Tetracycline; Transduction, Genetic; United Kingdom

Topics: Anti-Bacterial Agents; Chloramphenicol; gamma-Globulins; Kanamycin; Mice; Oxytetracycline; Pharmacology; Research; Salmonella; Salmonella Infections; Salmonella Infections, Animal; Streptomycin; Sulfisomidine; Sulfisoxazole; Tetracycline

Topics: Animals; Anti-Bacterial Agents; Blood Platelets; Bone Marrow Transplantation; Diarrhea; Haplorhini; Lymphocytes; Naphthyridines; Neutrophils; Penicillins; Pharmacology; Radiation Effects; Research; Salmonella Infections; Salmonella Infections, Animal; Salmonella paratyphi A; Salmonella typhi; Tetracycline; Typhoid-Paratyphoid Vaccines

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Chloramphenicol; Drug Resistance; Drug Resistance, Microbial; Research; Salmonella; Salmonella Infections; Salmonella Infections, Animal; Salmonella typhimurium; Tetracycline

Topics: Animals; Bird Diseases; Columbidae; Salmonella Infections, Animal; Streptomycin; Tetracycline