agar and Escherichia-coli-Infections

agar has been researched along with Escherichia-coli-Infections* in 44 studies

Other Studies

44 other study(ies) available for agar and Escherichia-coli-Infections

ArticleYear
Characterization and antimicrobial susceptibility of biofilm-producing Avian Pathogenic Escherichia coli from broiler chickens and their environment in India.
    Veterinary research communications, 2022, Volume: 46, Issue:2

    Avian pathogenic Escherichia coli (APEC) is responsible for colibacillosis in poultry. APEC remains a constant problem for the poultry industry, despite the use of antimicrobials and disinfectants in farms. The endemicity of APEC in poultry farms is associated with its biofilm-forming ability, which is further aggravated by various virulence factors and resistance to multiple drugs that help bacteria to thrive under different environmental conditions. To characterize APEC from affected broiler chickens and their environments, samples (n=114) from dead birds (heart, liver, lungs, and cloacal swab) and surrounding environments such as feeder, drinker, litter, PVC pipe, water tank wall, feed, and water were collected. The collected samples were subjected to microbial isolation using MacConkey Lactose agar (MLA) and Eosin Methylene Blue agar (EMB), which led to the isolation of 62 E. coli isolates. This was confirmed by uspA gene amplification and Vitek 2 Compact. These isolates were characterized using a set of five virulence genes (hlyF, ompT, iroN, iss, iutA), which yielded 47 (75.80%) isolates as APEC and the remaining as non-APEC. Furthermore, all the 62 isolates were subjected to microtiter plate assay for biofilm detection and the result showed that 36 (58.06%) isolates were able to form moderate to strong biofilms in Trypticase soy broth (TSB) at 72h of incubation. Of the 36 biofilm-producing isolates, 30 were APEC. Biofilm-related genes (crl, csgA, fimH, luxS, and papC) were also detected with higher prevalence among APEC isolates. Antimicrobial susceptibility test using Vitek 2 Compact revealed 43 (91.48%) of 47 APEC isolates as multiple drug resistant (MDR) and 8 (17.02%) as ESBL positive. This study reveals that APEC with biofilm formation ability is present in poultry farms. Further studies are needed to understand the role of biofilms in the pathogenesis and antimicrobial resistance of APEC.

    Topics: Agar; Animals; Anti-Bacterial Agents; Biofilms; Chickens; Escherichia coli; Escherichia coli Infections; Poultry; Poultry Diseases; Water

2022
Express detection of Escherichia coli and bacteria of the Escherichia coli group at the oral cavity.
    Klinicheskaia laboratornaia diagnostika, 2022, Mar-25, Volume: 67, Issue:3

    Currently, in the diagnosis of diseases, a decisive place is given to laboratory methods, which should be informative, relatively simple to perform and rapid. The article describes the approbation of a method for rapid detection of Escherichia coli and bacteria of Escherichia coli group in the oral cavity. Research involved 44 volunteers, who were sampled from the oral cavity, followed by incubation in Koda's medium. The study used oral (n=11) and gingival fluids (n=11); smears-prints from the oral mucosa (n=11); dental biofilm (n=11). After 24 hours, the change in color and transparency of the medium was assessed. The preservation of the initial green color and transparency by the medium meant the absence of E. coli and bacteria of Escherichia coli group in the sample. A change in the color of the medium to yellow, turbidity and / or the formation of bubbles indicated the presence of E. coli and bacteria of Escherichia coli group. In parallel, the material was inoculated onto Endo agar, followed by identification of strains to species. As a result of the study, a complete coincidence of the results of the classical bacteriological method and the method using Koda medium was shown. In the latter case, a significant advantage is the speed of obtaining the result (18-20 hours), in contrast to the classical method, the interpretation of the results of which is available only after 72 hours or more. All of this is in line with the state of the art in clinical microbiology and rapid diagnosis based on «point-of-care testing / doctor's office» diagnostic principle. The presented method can be successfully applied in clinical practice for topical diagnosis of microorganisms E. coli and bacteria of Escherichia coli group in the oral cavity.

    Topics: Agar; Culture Media; Escherichia coli; Escherichia coli Infections; Humans; Mouth

2022
Duck sewage source coliphage P762 can lyse STEC and APEC.
    Virus genes, 2022, Volume: 58, Issue:5

    Multiple pathogenic types or serotypes restrict treatment for colibacillosis. In addition, rising antibiotic resistance has heightened public awareness to prevent and control pathogenic Escherichia coli. The bacteriophage is a viable technique to treat colibacillosis as an alternative to antibiotics. P762, a coliphage isolated from duck farm sewage, was demonstrated to cloud lyse Shiga toxin-producing Escherichia Coli serotypes O157 and non-O157 (17/39), Avian pathogenic E. coli covered serotype O78, O83, and O9 (5/19), and other pathogenic Escherichia coli (5/17). Additional fundamental biological characteristics analysis revealed that P762 is stable at pH 3 ~ 11 and temperature between 4 °C and 60 °C, and its optimum multiplicity of infection (MOI) is 0.1. The one-step curve of P762 exhibited three bursts of growth stage: two rapid and one slow stage. Furthermore, the first rapid burst size is 80 CFU/PFU, the burst size of the slow stage is 10 CFU/PFU, and the second rapid burst size is about 990 CFU/PFU. In addition, P762 can form a "halo" on a double agar plate, implying that the phage secretes depolymerase. With 95.14% identity and 90% query coverage, genome sequence analysis revealed that P762 is most closely related to Escherichia phage DY1, which belongs to the genus Kayfunavirus. After screening using RAST and VFDB, no virulence factors were discovered in P762. In vitro antibacterial tests revealed that P762 has high bactericidal activity in lettuce leaves contaminated with STEC. In conclusion, phage P762 might be employed in the future to prevent and control pathogenic Escherichia coli.

    Topics: Agar; Animals; Anti-Bacterial Agents; Bacteriophages; Coliphages; Ducks; Escherichia coli Infections; Sewage; Shiga-Toxigenic Escherichia coli

2022
Antibiotic resistance pattern of methicillin-resistant
    The Pan African medical journal, 2022, Volume: 41

    mobile phone plays an essential role in the lives of healthcare professionals in hospitals as far as communication is concerned. However, it can also serve as a source of nosocomial infections. This study aimed at determining the prevalence and antibiotic susceptibility of Methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli isolated from mobile phones used by healthcare staff working in three public hospitals in Ghana.. in total, 220 swab samples were collected from 110 mobile phones of healthcare workers at a referral and two public tertiary hospitals in Ghana. Direct spreading of swab samples on agar plates was done. MacConkey agar and Baird Parker agar were used to isolate E. coli and S. aureus, respectively. Clinical Laboratory Standard Institute´s guidelines were followed for susceptibility testing, and S. aureus strains resistant to cefoxitin were considered to be MRSA. All E. coli and MRSA isolates were tested for their susceptibility to antibiotics using European Committee on Antimicrobial Susceptibility Testing (EUCAST) 2018 guidelines with its breakpoints. Obtained qualitative data were analyzed by using Microsoft Excel.. of 110 mobile phones, 78 (70.9%) and 4 (3.6%) were colonized with S. aureus and E. coli, respectively. From the 78 S. aureus isolates, 22 (28%) isolates were MRSA. Fifty percent (50%) (11/22) of the MRSA isolates were multi-drug resistant, of which one isolate was resistant to all antibiotics tested. E. coli isolates had 100 resistances to both ceftriaxone and ceftazidime.. mobile phones used by healthcare workers in hospitals frequently harbor E. coli, S. aureus, MRSA and may be sources of hospital-associated infections.

    Topics: Agar; Anti-Bacterial Agents; Cell Phone; Cross Infection; Drug Resistance, Microbial; Escherichia coli; Escherichia coli Infections; Ghana; Health Personnel; Hospitals, Public; Humans; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Staphylococcal Infections; Staphylococcus aureus

2022
Evaluation of distinct modes of oxidative secondary injury generated in heat-treated cells of Escherichia coli with solid/liquid and complex/semi-synthetic media sets.
    Journal of applied microbiology, 2022, Volume: 133, Issue:4

    To characterize and evaluate oxidative secondary injury generated in heat-treated Escherichia coli cells during recovery cultivation either on agar or in a broth of a semi-synthetic enriched M9 (EM9) medium and a complex Luria broth (LB) medium with different types of antioxidants.. E. coli cells grown in the EM9 and LB broth were heated at 50°C in a buffer (pH 7.0). Heated cells were recovered on the same kind of agar medium as that used for growth, with or without different antioxidants. Although these antioxidants mostly protected the cells from oxidative secondary injury on the recovery media, sodium thiosulphate and sodium pyruvate were most protective on EM9 and LB agars, respectively. Determination of viability using the most probable number and growth delay analysis methods showed significant reductions in the protective effects of antioxidants in the EM9 and LB media.. Oxidative secondary injury generated in heated E. coli cells was found to be qualitatively and quantitatively diverse under cellular and environmental conditions.. Our results suggest that different modes of oxidation should be considered in viability determination and injured cell enumeration of heat-treated cells.

    Topics: Agar; Antioxidants; Culture Media; Escherichia coli; Escherichia coli Infections; Hot Temperature; Humans; Oxidative Stress; Pyruvic Acid; Sodium

2022
Phenotypic and genotypic characterisation of thymine auxotrophy in Escherichia coli isolated from a patient with recurrent bloodstream infection.
    PloS one, 2022, Volume: 17, Issue:7

    Thymine auxotrophic in vitro mutants of Escherichia coli were first reported in the mid-20th century. Later, thymine-dependent clinical strains of E. coli as well as other Enterobacterales, Enterococcus faecalis and Staphylococcus aureus have been recognized as the cause of persistent and recurrent infections.. The aim of this study was to characterize the phenotype and investigate the molecular basis of thymine auxotrophy in ten E. coli isolates obtained at different time points from a patient with recurrent bloodstream infection (BSI) due to a chronic aortic graft infection treated with Trimethoprim/sulfamethoxazole (TMP-SMX).. Clinical data was obtained from hospital records. Growth characterization and antimicrobial susceptibility testing to TMP-SMX was performed on M9 agar and in MH broth with different thymine concentrations (0.5, 2, 5, 10 and 20 μg/mL), on Mueller-Hinton (MH) and blood agar. Whole genome sequencing (WGS) was performed on all E. coli isolates.. E. coli were isolated from ten consecutive BSI episodes from a patient with chronic aortic graft infection. Six of these isolates were resistant to TMP-SMX when assayed on blood agar. Growth experiments with added thymine confirmed that these isolates were thymine-dependent (thy-), and revealed growth defects (slower growth rate and smaller colony size) in these isolates relative to thy+ isolates (n = 4). WGS indicated that all isolates were of the same clonal lineage of sequence type 7358. Genomic analysis revealed a G172C substitution in thyA in all TMP-SMX resistant isolates, while mutations affecting genes involved in the deoxyribose salvage pathway (deoB and deoC) were identified in eight isolates.. This case highlights the risk of resistance development to TMP-SMX, especially for long-term treatment, and the possible pitfalls in detection of growth-deficient subpopulations from chronic infections, which could lead to treatment failure.

    Topics: Agar; Anti-Bacterial Agents; Escherichia coli; Escherichia coli Infections; Humans; Microbial Sensitivity Tests; Phenotype; Reinfection; Sepsis; Thymine; Trimethoprim, Sulfamethoxazole Drug Combination

2022
Implications of Escherichia coli community diversity in free-ranging Australian pinniped pups.
    Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases, 2022, Volume: 104

    Escherichia coli is a widely studied bacterium, commonly used as an indicator of faecal contamination. Investigations into the structure and diversity of E. coli in free-ranging wildlife species has been limited. The objective of this study was to characterise intra-individual and inter-species E. coli phylotype and B2 sub-type diversity in free-ranging Australian pinniped pups, to determine whether a single E. coli colony is representative of the phylotype and B2 sub-type diversity in these hosts. Faecal samples were collected from free-ranging Australian fur seal (Arctocephalus pusillus doriferus), Australian sea lion (Neophoca cinerea) and long-nosed fur seal (Arctocephalus forsteri) pups from three breeding colonies between 2018 and 2021. Faecal swabs from thirty randomly selected pups (n = 10 from each species) were cultured and ten E. coli colonies were selected from each culture based on morphology and separation between colonies on agar plates. Molecular screening techniques were utilised to assign isolates to phylotypes and B2 sub-types. There was no significant difference (p > 0.05) in either intra-individual or inter-species E. coli phylotype and B2 sub-type diversity. The B2 phylotype was the most dominant, with 78% of isolates (n = 234) assigned to this phylotype. Host factors (species, weight [kg] and standard length [cm]) did not significantly affect phylotype diversity. The absence of intra-individual and inter-species differences in E. coli diversity at a phylotype level suggests that a single E. coli colony could be used as an indicator of overall diversity of E. coli at a phylotype level in A. p. doriferus, N. cinerea and A. forsteri pups. These findings can be used to simplify and improve the efficiency of sampling protocols for ongoing monitoring of human-associated E. coli phylotypes in free-ranging pinniped populations.

    Topics: Agar; Animals; Australia; Escherichia coli; Escherichia coli Infections; Fur Seals; Sea Lions

2022
Antimicrobial Resistance, Virulence Factor-Encoding Genes, and Biofilm-Forming Ability of Community-Associated Uropathogenic
    Polish journal of microbiology, 2022, Sep-01, Volume: 71, Issue:3

    Topics: Agar; Ampicillin; Animals; Anti-Bacterial Agents; Biofilms; Drug Resistance, Bacterial; Ertapenem; Escherichia coli Infections; Female; Imipenem; Meropenem; Norfloxacin; Saudi Arabia; Sheep; Urinary Tract Infections; Uropathogenic Escherichia coli; Virulence Factors

2022
Genome-wide analysis of fitness factors in uropathogenic Escherichia coli in a pig urinary tract infection model.
    Microbiological research, 2022, Volume: 265

    Uropathogenic Escherichia coli (UPEC) is the primary cause of urinary tract infections (UTIs) in animals and humans. We applied Transposon-Directed Insertion Site sequencing (TraDIS) to determine the fitness genes in two well-characterized UPEC strains, UTI89 and CFT073, in order to identify fitness factors during UTI in a pig model. This novel animal model better reflects the course of UTI in humans than the commonly used mouse model, and facilitates the differentiation between sessile and planktonic UPEC populations. A total of 854 and 483 genes in UTI89 and CFT073, respectively, were predicted to contribute to growth in pig urine, and 1257 and 764, were scored as required for colonization of the bladder. The combined list of fitness genes for growth in urine and cystitis contained 741 (UTI89) and 439 (CFT073) genes. The essential genes for growth on LB agar media supplemented with kanamycin and the fitness factors during growth in human urine were also analyzed in CFT073. A total of 457 essential genes were identified and the pool of fitness genes for growth in human urine included 215 genes. The gene rfaG, which is involved in lipopolysaccharide biosynthesis, was included in all the fitness-gene-lists and was further confirmed to be relevant for all the conditions tested regardless of the host and the strain. Thus, this gene may represent a promising target for the development of new therapeutic strategies against UTI UPEC-associated. Besides this important observation, the study revealed strain-specific differences in gene-essentiality as well as in the fitness-gene-repertoire for growth in human urine and UTI of the pig model, and it identified novel factors required for UPEC-induced UTIs.

    Topics: Agar; Animals; Disease Models, Animal; Escherichia coli Infections; Escherichia coli Proteins; Humans; Kanamycin; Lipopolysaccharides; Mice; Swine; Urinary Tract Infections; Uropathogenic Escherichia coli

2022
Investigation of the Role of Virulence Gene in Biofilm Formation of
    Archives of Razi Institute, 2022, Volume: 77, Issue:2

    Several strains of

    Topics: Adolescent; Adult; Agar; Anti-Bacterial Agents; Biofilms; Child; Escherichia coli; Escherichia coli Infections; Female; Heat-Shock Proteins; Humans; Male; Urinary Tract Infections; Virulence; Young Adult

2022
Validation of Selective Agars for Detection and Quantification of Escherichia coli Strains Resistant to Critically Important Antimicrobials.
    Microbiology spectrum, 2021, 12-22, Volume: 9, Issue:3

    Success in the global fight against antimicrobial resistance (AMR) is likely to improve if surveillance can be performed on an epidemiological scale. An approach based on agars with incorporated antimicrobials has enormous potential to achieve this. However, there is a need to identify the combinations of selective agars and key antimicrobials yielding the most accurate counts of susceptible and resistant organisms. A series of experiments involving 1,202 plates identified the best candidate combinations from six commercially available agars and five antimicrobials, using 18 Escherichia coli strains as either pure cultures or inocula-spiked feces. The effects of various design factors on colony counts were analyzed in generalized linear models. Without antimicrobials, Brilliance E. coli and CHROMagar ECC agars yielded 28.9% and 23.5% more colonies, respectively, than MacConkey agar. The order of superiority of agars remained unchanged when fecal samples with or without spiking of resistant E. coli strains were inoculated onto agars with or without specific antimicrobials. When antimicrobials were incorporated at various concentrations, it was revealed that ampicillin, tetracycline, and ciprofloxacin were suitable for incorporation into Brilliance and CHROMagar agars at all defined concentrations. Gentamicin was suitable for incorporation only at 8 and 16 μg/ml, while ceftiofur was suitable only at 1 μg/ml. CHROMagar extended-spectrum β-lactamase (ESBL) agar supported growth of a wider diversity of extended-spectrum-cephalosporin-resistant E. coli strains. The findings demonstrate the potential for agars with incorporated antimicrobials to be combined with laboratory-based robotics to deliver AMR surveillance on a vast scale with greater sensitivity of detection and strategic relevance.

    Topics: Agar; Animals; Anti-Bacterial Agents; Cephalosporins; Diagnostic Tests, Routine; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Feces; Humans; Livestock; Microbial Sensitivity Tests

2021
Rapid detection of fosfomycin resistance in Escherichia coli and Klebsiella spp. strains isolated from urinary tract infections.
    Journal of microbiological methods, 2021, Volume: 188

    This study evaluates whether the rapid fosfomycin resistance (fosfomycin NP) method can be used for detecting fosfomycin resistance in routine laboratory work. Results from the disk diffusion and rapid fosfomycin NP methods were compared with the reference agar dilution method for Escherichia coli and Klebsiella spp. strains isolated from urinary tract infections. The study included 57 E. coli and 48 Klebsiella spp. isolates from urinary tract infections. The reference agar dilution and disk diffusion methods were performed in accordance with EUCAST recommendations, and the results were evaluated according to EUCAST V.10.0. The method developed by Nordmann et al. was used for rapid detection of fosfomycin resistance (Nordmann, P., Poirel, L., Mueller, L., 2019. Rapid Detection of Fosfomycin Resistance in Escherichia coli. J Clin Microbiol. 57(1), e01531-18. doi:https://doi.org/10.1128/JCM.01531-18). The acceptable categorical agreement (CA ≥ 90%) and the rates of major error (ME <3%) and very major error (VME < 3%) of the two methods were compared with the reference method according to the criteria of ISO 20776-1. Fosfomycin resistance was detected in 15.8% of E. coli and 75% of Klebsiella spp. isolates using the reference method. Disk diffusion method showed CA 89.5%, ME 12.5% in E. coli isolates, and CA 75%, ME 100% in Klebsiella spp. isolates. No VME was detected in both methods. The rapid fosfomycin NP method resulted in CA 96.4%, ME 0.0%, VME 22.2% in E. coli isolates, and CA 77.3%, ME 81.8%, and VME 3% in Klebsiella spp. isolates. We believe the results from both of disk diffusion assay and rapid fosfomycin NP for the E. coli and Klebsiella spp. isolates are incompatible with the reference method and should not be used as an alternative to the agar dilution method.

    Topics: Agar; Anti-Bacterial Agents; Diagnostic Tests, Routine; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Fosfomycin; Humans; Klebsiella; Klebsiella Infections; Klebsiella pneumoniae; Microbial Sensitivity Tests; Urinary Tract Infections

2021
Raman microspectroscopy differentiates perinatal pathogens on ex vivo infected human fetal membrane tissues.
    Journal of biophotonics, 2019, Volume: 12, Issue:9

    Streptococcus agalactiae, also known as Group B Streptococcus (GBS), is a major cause of chorioamnionitis and neonatal sepsis. This study evaluates Raman spectroscopy (RS) to identify spectral characteristics of infection and differentiate GBS from Escherichia coli and Staphylococcus aureus during ex vivo infection of human fetal membrane tissues. Unique spectral features were identified from colonies grown on agar and infected fetal membrane tissues. Multinomial logistic regression analysis accurately identified GBS infected tissues with 100.0% sensitivity and 88.9% specificity. Together, these findings support further investigation into the use of RS as an emerging microbiologic diagnostic tool and intrapartum screening test for GBS carriage.

    Topics: Agar; Algorithms; Anti-Bacterial Agents; Chorioamnionitis; Escherichia coli; Escherichia coli Infections; Extraembryonic Membranes; Female; Humans; Logistic Models; Microbiological Techniques; Pregnancy; Regression Analysis; Spectrum Analysis, Raman; Staphylococcal Infections; Staphylococcus aureus; Streptococcal Infections; Streptococcus agalactiae

2019
Isolation of Shiga Toxin-Producing Escherichia coli from Ground Beef Using Multiple Combinations of Enrichment Broths and Selective Agars.
    Foodborne pathogens and disease, 2016, Volume: 13, Issue:3

    Shiga toxin-producing Escherichia coli (STEC) are foodborne pathogens, and beef cattle are recognized as the principal reservoir. The aims of this study were (1) to identify the most sensitive combination of selective enrichment broths and agars for STEC isolation in artificially inoculated ground beef samples, and (2) to evaluate the most efficient combination(s) of methods for naturally contaminated ground beef samples. A total of 192 ground beef samples were artificially inoculated with STEC and non-stx bacterial strains. A combination of four enrichment broths and three agars were evaluated for sensitivity, specificity, and positive predictive value for STEC isolation from experimentally inoculated samples. Enrichments with either modified tryptic soy broth (mTSB) containing 8 mg/L novobiocin (mTSB-8) or modified Escherichia coli (mEC) broth followed by isolation in MacConkey agar were the most sensitive combinations for STEC isolation of artificially inoculated samples. Independently, both enrichments media followed by isolation in MacConkey were used to evaluate ground beef samples from 43 retail stores, yielding 65.1% and 58.1% stx-positive samples by RT-PCR, respectively. No difference was observed in the isolate proportions between these two methods (8/25 [32%] and 8/28 [28.6%]). Identical serotypes and stx genotypes were observed in STEC strains isolated from the same samples by either method. In this study, no single enrichment protocol was sufficient to detect all STEC in artificially inoculated samples and had considerable variation in detection ability with naturally contaminated samples. Moreover, none of the single or combinations of multiple isolation agars used were capable of identifying all STEC serogroups in either artificially inoculated or naturally occurring STEC-contaminated ground beef. Therefore, it may be prudent to conclude that there is no single method or combination of isolation methods capable of identifying all STEC serogroups.

    Topics: Agar; Animals; Cattle; Culture Media; Escherichia coli Infections; Food Microbiology; Foodborne Diseases; Red Meat; Shiga Toxin; Shiga-Toxigenic Escherichia coli

2016
Comparison of Six Chromogenic Agar Media for the Isolation of a Broad Variety of Non-O157 Shigatoxin-Producing Escherichia coli (STEC) Serogroups.
    International journal of environmental research and public health, 2015, Jun-17, Volume: 12, Issue:6

    The isolation of non-O157 STEC from food samples has proved to be challenging. The selection of a suitable selective isolation agar remains problematic. The purpose of this study was to qualitatively and quantitatively evaluate six chromogenic agar media for the isolation of STEC: Tryptone Bile X-glucuronide agar (TBX), Rainbow® Agar O157 (RB), Rapid E. coli O157:H7 (RE), Modified MacConkey Agar (mMac), CHROMagarTM STEC (Chr ST) and chromIDTM EHEC (Chr ID). During this study, 45 E. coli strains were used, including 39 STEC strains belonging to 16 different O serogroups and 6 non-STEC E. coli. All E. coli strains were able to grow on TBX and RB, whereas one STEC strain was unable to grow on Chr ID and a number of other STEC strains did not grow on mMac, CHROMagar STEC and Rapid E. coli O157:H7. However, only the latter three agars were selective enough to completely inhibit the growth of the non-STEC E. coli. Our conclusion was that paired use of a more selective agar such as CHROMagar STEC together with a less selective agar like TBX or Chr ID might be the best solution for isolating non-O157 STEC from food.

    Topics: Agar; Culture Media; Escherichia coli Infections; Humans; Serogroup; Shiga-Toxigenic Escherichia coli

2015
Practical agar-based disk potentiation test for detection of fosfomycin-nonsusceptible Escherichia coli clinical isolates producing glutathione S-transferases.
    Journal of clinical microbiology, 2014, Volume: 52, Issue:9

    The number of reports concerning Escherichia coli clinical isolates that produce glutathione S-transferases responsible for fosfomycin resistance (FR-GSTs) has been increasing. We have developed a disk-based potentiation test in which FR-GST producers expand the growth inhibition zone around a Kirby-Bauer disk containing fosfomycin in combination with sodium phosphonoformate (PPF). PPF, an analog of fosfomycin, is a transition-state inhibitor of FosA(PA), a type of FR-GST from Pseudomonas aeruginosa. Considering its mechanism of action, PPF was expected to inhibit a variety of FR-GSTs. In the presence of PPF, zone enlargement around the disk containing fosfomycin was observed for FosA3-, FosA4-, and FosC2-producing E. coli clinical isolates. Moreover, the growth inhibition zone was remarkably enlarged when the Mueller-Hinton (MH) agar plate contained 25 μg/ml glucose-6-phosphate (G6P). When we retrospectively tested 12 fosfomycin-resistant (MIC, ≥256 μg/ml) E. coli clinical isolates from our hospital with the potentiation test, 6 FR-GST producers were positive phenotypically by potentiation disk and were positive for FR-GST genes: 5 harbored fosA3 and 1 harbored fosA4. To identify the production of FR-GSTs, we set the provisional cutoff value, 5-mm enlargement, by adding PPF to a fosfomycin disk on the MH agar plates containing G6P. Our disk-based potentiation test reliably identifies FR-GST producers and can be performed easily; therefore, it will be advantageous in epidemiological surveys and infection control of fosfomycin-resistant bacteria in clinical settings.

    Topics: Agar; Anti-Bacterial Agents; Culture Media; DNA, Bacterial; Drug Tolerance; Escherichia coli; Escherichia coli Infections; Foscarnet; Fosfomycin; Glutathione Transferase; Humans; Microbial Sensitivity Tests; Molecular Sequence Data; Pseudomonas aeruginosa; Sequence Analysis, DNA

2014
A modified MacConkey agar for selective enumeration of necrotoxigenic E. coli O55 and probiotic E. coli Nissle 1917.
    Journal of microbiological methods, 2014, Volume: 104

    An agar selective enumeration of necrotoxigenic Escherichia coli O55 (NTEC2) and probiotic E. coli Nissle 1917, using modified MacConkey agar, was developed to study bacterial interference between these E. coli strains in a gnotobiotic piglet model. Replacement of lactose with saccharose in the agar enables the direct visual enumeration of red colonies of E. coli O55 and yellow colonies of E. coli Nissle 1917 that are co-cultured in the same Petri dish. A total of 336 colonies (168 for each color) were subjected to strain-specific PCR identification with LNA probes. Sensitivity, specificity, and positive and negative predictive values were 96.43%, 95.83%, 95.86% and 96.41% respectively in E. coli O55, and 98.21%, 97.02%, 97.06% and 98.19% respectively in E. coli Nissle 1917. Color-based enumeration of both E. coli strains in colonic contents and mesenteric lymph nodes homogenates of gnotobiotic piglets demonstrated the applicability of this method for the gnotobiotic piglet model of enteric diseases.

    Topics: Agar; Animals; Colony Count, Microbial; Color; Culture Media; Escherichia coli; Escherichia coli Infections; Humans; Probiotics; Swine

2014
Evaluation of CHROMagar STEC and STEC O104 chromogenic agar media for detection of Shiga Toxin-producing Escherichia coli in stool specimens.
    Journal of clinical microbiology, 2013, Volume: 51, Issue:3

    The performance of CHROMagar STEC and CHROMagar STEC O104 (CHROMagar Microbiology, Paris, France) media for the detection of Shiga toxin-producing Escherichia coli (STEC) was assessed with 329 stool specimens collected over 14 months from patients with suspected STEC infections (June 2011 to August 2012). The CHROMagar STEC medium, after an enrichment broth step, allowed the recovery of the STEC strain from 32 of the 39 (82.1%) Shiga toxin-positive stool specimens, whereas the standard procedure involving Drigalski agar allowed the recovery of only three additional STEC strains. The isolates that grew on CHROMagar STEC medium belonged to 15 serotypes, including the prevalent non-sorbitol-fermenting (NSF) O157:H7, O26:H11, and O104:H4 serotypes. The sensitivity, specificity, and positive and negative predictive values for the CHROMagar STEC medium were between 89.1% and 91.4%, 83.7% and 86.7%, 40% and 51.3%, and 98% and 98.8%, respectively, depending on whether or not stx-negative eae-positive E. coli was considered atypical enteropathogenic E. coli (EPEC) or STEC that had lost Shiga toxin genes during infection. In conclusion, the good performance of CHROMagar STEC agar medium, in particular, the high negative predictive value, and its capacity to identify NSF O157:H7 as well as common non-O157 STEC may be useful for clinical bacteriology, public health, and reference laboratories; it could be used in addition to a method targeting Shiga toxins (detection of stx genes by PCR, immunodetection of Shiga toxins in stool specimens, or Vero cell cytotoxicity assay) as an alternative to O157 culture medium. This combined approach should allow rapid visualization of both putative O157 and non-O157 STEC colonies for subsequent characterization, essential for real-time surveillance of STEC infections and investigations of outbreaks.

    Topics: Adolescent; Adult; Agar; Bacteriological Techniques; Child; Child, Preschool; Chromogenic Compounds; Culture Media; Escherichia coli Infections; Feces; Humans; Predictive Value of Tests; Sensitivity and Specificity; Shiga-Toxigenic Escherichia coli

2013
[Etiological bacterial level in enterohemorrhagic Escherichia coli infection feces and chromogenic culture medium CHROMagar STEC usefulness].
    Kansenshogaku zasshi. The Journal of the Japanese Association for Infectious Diseases, 2011, Volume: 85, Issue:6

    We report a case of enterohemorrhagic Escherichia coli (EHEC) infection in which EHEC was not detected by culture on DHL agar medium. The proportion of EHEC bacterial count to enterobacterial count in feces was 1.7%, and the detection probability by 5-colony angling was low (8.1%). The probability of angling detection using CHROMagar STEC, a chromogenic medium for detecting EHEC, was high (100%). An additional and collection test was done using E. coli bacterial solutions to which two main sera groups--O157 and O26 were added. The maximum detectable level in the bacterial solution with O157 was 10(3)-10(4) CFU/mL in DHL and 10(2) CFU/mL in CHROMagar STEC. Bacterial solution levels with O26 were 10(3) CFU/mL in DHL and 10(2) CFU/mL in CHROMagar STEC. Assuming that the EHEC bacterial amount in feces of those with EHEC infection is low, we speculated that CHROMagar STEC may be useful as on EHEC screening medium.

    Topics: Agar; Chromogenic Compounds; Culture Media; Enterohemorrhagic Escherichia coli; Escherichia coli Infections; Escherichia coli O157; Feces; Humans

2011
Comparison of media for the selective culture of enteroinvasive Escherichia coli.
    European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology, 2003, Volume: 22, Issue:4

    MacConkey, eosine-methylene blue, deoxycholate-citrate, salmonella-shigella, and xylose-lysine-deoxycholate agars were compared for their ability to support the growth and to facilitate the recovery of enteroinvasive Escherichia coli strains from artificially contaminated as well as from clinical faecal samples. When grown as pure cultures, the 78 enteroinvasive Escherichia coli strains, as a group, exhibited the same growth characteristics as did Shigella isolates ( n=59), i.e. both organisms grew more weakly than did Salmonella strains ( n=22) on the various selective plates but 4- to 10-fold better than normal Escherichia coli isolates ( n=53). Xylose-lysine-deoxycholate and deoxycholate-citrate plates were more effective in recovering enteroinvasive Escherichia coli from faecal samples than was salmonella-shigella agar. Likewise, xylose-lysine-deoxycholate agar, similar to the differentiating MacConkey and eosine-methylene blue agars, was less inhibitory for defined "sensitive" strains than were the selective media tested. Preincubating clinical faecal samples in selenite F or in gram-negative broth did not influence the recovery of enteroinvasive Escherichia coli significantly. These data show that the use of xylose-lysine-deoxycholate, in combination with MacConkey or eosine-methylene blue agar, provides the best chance for recovery of enteroinvasive Escherichia coli when randomly selecting colonies from faecal cultures for subsequent molecular or immunological identification assays.

    Topics: Agar; Antigens, Bacterial; Bacteriological Techniques; Culture Media; Diarrhea; Enzyme-Linked Immunosorbent Assay; Escherichia coli; Escherichia coli Infections; Feces; Humans; Polymerase Chain Reaction; Virulence

2003
Evaluation of Chromocult coliform agar for the detection and enumeration of Enterobacteriaceae from faecal samples from healthy subjects.
    Journal of microbiological methods, 2003, Volume: 54, Issue:3

    The purpose of this study was to examine the use of Chromocult agar medium for isolation and enumeration of Enterobacteriaceae from human faecal samples, to compare it to MacConkey agar and to evaluate its usefulness as a possible alternative selective medium in human faecal studies. The medium was shown to be effective in identifying Escherichia coli and coliforms in faeces without the need for extensive accompanying biochemical tests for confirmation of identity. A positive correlation (r=0.86) was found between the recovery of Enterobacteriaceae on the two media, and no significant difference (P>0.05) between overall mean bacterial counts for the whole study group or at different intervals of faecal collection were observed. Chromocult agar is an effective replacement for MacConkey agar in human faecal studies and has the advantage of differentiating E. coli from other coliforms.

    Topics: Agar; Bacteriological Techniques; Chromogenic Compounds; Colony Count, Microbial; Escherichia coli; Escherichia coli Infections; False Negative Reactions; False Positive Reactions; Feces; Humans

2003
Comparative evaluation of three chromogenic agars for detection and rapid identification of aerobic Gram-negative bacteria in the normal intestinal microflora.
    Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases, 2003, Volume: 9, Issue:9

    To compare three different chromogenic agars and MacConkey agar for the detection of aerobic Gram-negative bacteria in the normal intestinal microflora and to assess the accuracy of the chromogenic agars for the direct identification of Escherichia coli.. A total of 164 Gram-negative clinical isolates (E. coli, Proteus, Klebsiella, Enterobacter, Morganella and Pseudomonas species) and 30 stool specimens were inoculated in parallel on four media: Chromagar E. coli/Coliform, Chromogenic urinary tract infection UTI medium, CHROMagar Orientation and MacConkey agar. All colonies that differed by color and/or morphology were selected for further identification by VITEK 1 and/or API 20E from each medium.. On E. coli/Coliform agar five out of 32 (16%) E. coli strains failed to produce the color as described by the manufacturer. No remarkable discrepancies were found for the other clinical isolates. There was no significant difference in detection rate (DR) of aerobic Gram-negative bacteria in stool specimens between the different chromogenic agars and MacConkey agar. The overall DR was about 84%, and varied from 100% for monomicrobial specimens to 33% for polymicrobial specimens. The positive predictive values (PPV) for the direct identification of E. coli on Chromagar E. coli/Coliform, Chromogenic UTI medium and CHROMagar Orientation were 1.00, 0.93 and 0.93, respectively. The negative predictive values (NPV) were 0.53, 0.68 and 0.69, respectively.. Chromogenic UTI medium and CHROMagar Orientation are the preferred media because of the higher NPV. The high PPV of these agars allows accurate and rapid identification of E. coli.

    Topics: Agar; Chromogenic Compounds; Culture Media; Escherichia coli; Escherichia coli Infections; Feces; Gram-Negative Bacteria; Humans; Intestinal Diseases; Predictive Value of Tests

2003
Shiga toxin-producing E coli: two tests are better than one.
    The Journal of pediatrics, 2002, Volume: 141, Issue:2

    Topics: Adolescent; Agar; Child; Child Welfare; Child, Preschool; Diarrhea; Escherichia coli; Escherichia coli Infections; Feces; Humans; Immunoenzyme Techniques; Infant; Infant Welfare; Polymerase Chain Reaction; Shiga Toxin

2002
Novel single-tube agar-based test system for motility enhancement and immunocapture of Escherichia coli O157:H7 by H7 flagellar antigen-specific antibodies.
    Journal of clinical microbiology, 2002, Volume: 40, Issue:12

    This paper describes a novel single-tube agar-based technique for motility enhancement and immunoimmobilization of Escherichia coli O157:H7. Motility indole ornithine medium and agar (0.4%, wt/vol) media containing either nutrient broth, tryptone broth, or tryptic soy broth (TSBA) were evaluated for their abilities to enhance bacterial motility. Twenty-six E. coli strains, including 19 O157:H7 strains, 1 O157:H(-) strain, and 6 generic E. coli strains, were evaluated. Test bacteria were stab inoculated in the center of the agar column, and tubes were incubated at 37 degrees C for 18 to 96 h. Nineteen to 24 of the 26 test strains (73.1 to 92.3%) were motile in the different media. TSBA medium performed best and was employed in subsequent studies of motility enhancement and H7 flagellar immunocapture. H7 flagellar antiserum (30 and 60 micro l) mixed with TSBA was placed as a band (1 ml) in the middle of an agar column separating the top (3-ml) and bottom (3-ml) agar layers. The top agar layer was inoculated with the test bacterial strains. The tubes were incubated at 37 degrees C for 12 to 18 h and for 18 to 96 h. The specificity and sensitivity of the H7 flagellar immunocapture tests were 75 and 100%, respectively. The procedure described is simple and sensitive and could be adapted easily for routine use in laboratories that do not have sophisticated equipment and resources for confirming the presence of H7 flagellar antigens. Accurate and rapid identification of H7 flagellar antigen is critical for the complete characterization of E. coli O157:H7, owing to the immense clinical, public health, and economic significance of this food-borne pathogen.

    Topics: Agar; Animals; Antigens, Bacterial; Bacteriological Techniques; Culture Media; Escherichia coli Infections; Escherichia coli O157; Humans; Immunoassay; Meat Products; Movement; Sensitivity and Specificity

2002
Use of eosin methylene blue agar to differentiate Escherichia coli from other gram-negative mastitis pathogens.
    Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc, 2001, Volume: 13, Issue:3

    Topics: Agar; Animals; Cattle; Diagnosis, Differential; Enzyme Inhibitors; Eosine Yellowish-(YS); Escherichia coli Infections; Female; Food Contamination; Gram-Negative Bacterial Infections; Mastitis, Bovine; Methylene Blue; Sensitivity and Specificity; Specimen Handling

2001
Comparison of sorbitol MacConkey agar and a two-step method which utilizes enzyme-linked immunosorbent assay toxin testing and a chromogenic agar to detect and isolate enterohemorrhagic Escherichia coli.
    Journal of clinical microbiology, 2000, Volume: 38, Issue:2

    Enterohemorrhagic Escherichia coli (EHEC) and specifically serotype O157:H7 are a significant cause of hemorrhagic gastrointestinal disease and the hemolytic uremic syndrome. Methods currently used in clinical microbiology labs, such as sorbitol-MacConkey (SMAC) agar, reliably detect only O157:H7. We have evaluated a two-step method that has the potential to identify and isolate all EHEC serotypes, including serotype O157:H7. This method utilizes a chromogenic selective-differential medium for the isolation of E. coli together with an enzyme-linked immunosorbent assay (ELISA) that detects the Shiga-like toxins Stx1 and Stx2. Both are commercially available and usable in a wide range of clinical microbiology laboratories. Compared to a Vero cell cytotoxic assay, SMAC had sensitivities of 23.5% for the identification of all EHEC serotypes and of 50.0% for the identification of O157:H7 alone. The two-step method had sensitivities of 76.5 and 100%, respectively. The ELISA alone had a sensitivity of 82.4% in the detection of Stx1 and Stx2. The specificity was 100% in all cases. Overall, 14 EHEC isolates were obtained: 8 (58%) O157:H7, 2 (14%) O26, 2 (14%) O111:NM, 1 (7%) O103:H2, and 1 (7%) O121:H19. All but one were isolated during the months of May to September. The two-step method was found to be considerably more expensive than SMAC for both positive and negative samples.

    Topics: Agar; Animals; Bacterial Toxins; Bacterial Typing Techniques; Chlorocebus aethiops; Chromogenic Compounds; Culture Media; Cytotoxicity Tests, Immunologic; Enzyme-Linked Immunosorbent Assay; Escherichia coli; Escherichia coli Infections; Humans; Serotyping; Shiga Toxins; Vero Cells

2000
Performance of Uricult Trio assessed by a comparison method and external control panels in primary healthcare.
    Scandinavian journal of clinical and laboratory investigation, 2000, Volume: 60, Issue:5

    Using the comparison method, we have evaluated the technical performance of Uricult Trio by culturing on Uricult Trio and agar plates. Urine samples (477) from patients in primary healthcare were cultured in parallel in a microbiology laboratory. The result for Uricult Trio evaluated using the comparison method was incorrect in 32% of the cultures. We also studied the performance of Uricult Trio when used in primary healthcare by using external control panels. External control panels consisting of Uricult Trio, inoculated with known concentrations of certain bacterial strains, were used to assess the performance of Uricult Trio in primary healthcare during the period 1993-7. Aberrations in reports of concentration have ranged from 10% to 33%, failure in reporting of mixed culture from 0% to 91% and reporting of E. coli from 15% to 86%. There has been no sign of improvement over the years. The results indicate that Uricult Trio is unsuitable for indications other than exclusion of urinary tract infection or diagnosis of urinary tract infection caused by E. coli. Further, there is need for quality assurance and training activities at primary healthcare laboratories, probably best carried out in collaboration with local clinical microbiology laboratories.

    Topics: Agar; Colony Count, Microbial; Culture Media; Escherichia coli Infections; False Negative Reactions; Female; Humans; Male; Point-of-Care Systems; Quality Control; Reagent Kits, Diagnostic; Reproducibility of Results; Sweden; Urinary Tract Infections

2000
Evaluation of two methods for improving quality of diagnosis of bacteriuria by culture in primary healthcare.
    Scandinavian journal of clinical and laboratory investigation, 2000, Volume: 60, Issue:5

    This study evaluates the effect of training on the results from Uricult Trio and an established urine culture when used at primary healthcare laboratories in two Swedish counties, Uppsala and Värmland. Urine cultures and dipslides, Uricult Trio, performed at these laboratories were interpreted a second time at central laboratories. Interpretation errors at the primary healthcare laboratories were calculated. Primary healthcare laboratories also received external control panels with urine cultures and dipslides. There was one study period each year for 3 years in Uppsala and for 2 years in Värmland. A training programme was completed between study periods in Värmland. In Uppsala, primary healthcare laboratory results could be reviewed, as interpretations by the central laboratory were returned to them. The main outcome measures were the percentage of interpretation errors which, in the first study period, was 33-39%. This dropped to 15-19% in the second study period. In the results from the external control panels there were no striking differences between the studied areas and Sweden as a whole, except that Uppsala showed a better result in reporting E. coli and failed in 10% compared to Sweden 46%. A method for both quality assessment and education is to ask the primary healthcare laboratories to send cultures to the central laboratory for interpretation requesting their return to the primary healthcare laboratory with the interpretation from the central laboratory attached.

    Topics: Agar; Bacteriuria; Colony Count, Microbial; Escherichia coli Infections; Female; Humans; Male; Point-of-Care Systems; Primary Health Care; Quality Control; Reagent Kits, Diagnostic; Research Design; Sweden; Urinary Tract Infections

2000
Studies of Escherichia coli cultured on Rainbow Agar O157 with particular reference to enterohaemorrhagic Escherichia coli (EHEC).
    Microbiology and immunology, 1998, Volume: 42, Issue:4

    Rainbow Agar O157 is designed for the rapid isolation and identification of enterohaemorrhagic Escherichia coli (EHEC), particularly O157, characterised by black colonies. Five-hundred-eighty-five E. coli strains, including O157, O111 and O113 serogroups from many sources were examined on Rainbow Agar O157. EHEC O157 could readily be isolated and recognized uniquely by typical black colonies. Some other EHEC also stand out as blue-black, whereas O113 and some other EHEC strains were mauve, red or pink and indistinguishable from SLT-negative strains of E. coli.

    Topics: Agar; Bacterial Toxins; beta-Galactosidase; Chromogenic Compounds; Culture Media; Enterotoxins; Escherichia coli; Escherichia coli Infections; Escherichia coli O157; Glucuronidase; Humans; Reagent Kits, Diagnostic; Serotyping

1998
Development of a colony lift immunoassay to facilitate rapid detection and quantification of Escherichia coli O157:H7 from agar plates and filter monitor membranes.
    Clinical and diagnostic laboratory immunology, 1998, Volume: 5, Issue:4

    E. coli O157:H7 is a food-borne adulterant that can cause hemorrhagic ulcerative colitis and hemolytic uremic syndrome. Faced with an increasing risk of foods contaminated with E. coli O157:H7, food safety officials are seeking improved methods to detect and isolate E. coli O157:H7 in hazard analysis and critical control point systems in meat- and poultry-processing plants. A colony lift immunoassay was developed to facilitate the positive identification and quantification of E. coli O157:H7 by incorporating a simple colony lift enzyme-linked immunosorbent assay with filter monitors and traditional culture methods. Polyvinylidene difluoride (PVDF) membranes (Millipore, Bedford, Mass.) were prewet with methanol and were used to make replicates of every bacterial colony on agar plates or filter monitor membranes that were then reincubated for 15 to 18 h at 36 +/- 1 degree C, during which the colonies not only remained viable but were reestablished. The membranes were dried, blocked with blocking buffer (Kirkegaard and Perry Laboratories [KPL], Gaithersburg, Md.), and exposed for 7 min to an affinity-purified horseradish peroxidase-labeled goat anti-E. coli O157 antibody (KPL). The membranes were washed, exposed to a 3,3',5,5'-tetramethylbenzidine membrane substrate (TMB; KPL) or aminoethyl carbazole (AEC; Sigma Chemical Co., St. Louis, Mo.), rinsed in deionized water, and air dried. Colonies of E. coli O157:H7 were identified by either a blue (via TMB) or a red (via AEC) color reaction. The colored spots on the PVDF lift membrane were then matched to their respective parent colonies on the agar plates or filter monitor membranes. The colony lift immunoassay was tested with a wide range of genera in the family Enterobacteriaceae as well as different serotypes within the E. coli genus. The colony lift immunoassay provided a simple, rapid, and accurate method for confirming the presence of E. coli O157:H7 colonies isolated on filter monitors or spread plates by traditional culture methods. An advantage of using the colony lift immunoassay is the ability to test every colony serologically on an agar plate or filter monitor membrane simultaneously for the presence of the E. coli O157 antigen. This colony lift immunoassay has recently been successfully incorporated into a rapid-detection, isolation, and quantification system for E. coli O157:H7, developed in our laboratories for retail meat sampling.

    Topics: Agar; Antibodies, Bacterial; Antibody Specificity; Antigens, Bacterial; Colony Count, Microbial; Enzyme-Linked Immunosorbent Assay; Escherichia coli Infections; Escherichia coli O157; Evaluation Studies as Topic; Food Microbiology; Foodborne Diseases; Humans; Meat; Micropore Filters

1998
Comparison of the beta-glucuronidase assay and the conventional method for identification of Escherichia coli on eosin-methylene blue agar.
    Journal of food protection, 1997, Volume: 60, Issue:1

    The purpose of this study was to compare the IMViC (indole, methyl red, Voges-Proskauer and citrate utilization) tests with the beta-glucuronidase (GUD) assay for the identification of suspect Escherichia coli on Levine's eosin-methylene blue (EMB) agar. After testing 258 suspect E. coli colonies from raw meat and meat products, 163 and 44 were found to be E. coli and non-E. coli, respectively, by both methods. Nine isolates were IMViC positive (i.e., + + - - or - + - -) but GUD negative; among these isolates, six were confirmed to be E. coli by API 20E (bioMerieux, Marcy-I'Etoile, France) with the remaining three being non-E. coli. There were 42 isolates that were IMViC negative but GUD positive; among these isolates, seven were pure E. coli cultures, 33 were mixed cultures containing E. coli, and the remaining two were Proteus spp. The sensitivities for the identification of E. coli on EMB were 80.9% (169/209) and 97.1% (203/209), respectively, by the IMViC tests and GUD assay; whereas the specificities were 93.9% (46/49) and 95.9% (47/49), respectively, by the IMViC tests and GUD assay. It is proposed that the GUD assay can be an effective alternative to the conventional IMViC tests for the identification of suspect E. coli on EMB.

    Topics: Agar; Bacteriological Techniques; Colony Count, Microbial; Culture Media; Eosine Yellowish-(YS); Escherichia coli; Escherichia coli Infections; Glucuronidase; Humans; Meat; Meat Products; Methylene Blue; Sensitivity and Specificity

1997
Rapid Immunoassay for detection of Escherichia coli O157 directly from stool specimens.
    Journal of clinical microbiology, 1996, Volume: 34, Issue:4

    A new and rapid ( < 1 h) enzyme-linked immunosorbent assay (ELISA) was compared with conventional sorbitol-MacConkey agar (SMAC) culture for the detection of Escherichia coli O157 from stool specimens. Among 34 positive specimens, confirmed by colony-sweeping and immunofluorescence stain methods, 6 did not exhibit visible sorbitol-negative colonies on SMAC. These six specimens would have been considered to be negative if SMAC alone had been used. The ELISA detected 31 of the 34 positive samples, including 5 of the above-mentioned 6 false-negative samples, resulting in a sensitivity and specificity of 91.2 and 99.5%, respectively. Cross-reactivity with other enteric pathogens was not noted by ELISA. The SMAC method had a sensitivity and specificity of 82.4 and 100%, respectively. The ELISA-negative specimens do not require culture confirmation, whereas positive results must be considered to be presumptive until confirmed by culture. The test is accurate and is easy to perform, making it a very efficient method for screening stool specimens for E. coli O157.

    Topics: Agar; Bacteriological Techniques; Colitis; Culture Media; Diagnostic Errors; Enzyme-Linked Immunosorbent Assay; Escherichia coli; Escherichia coli Infections; Evaluation Studies as Topic; Feces; Humans; Sensitivity and Specificity; Sorbitol

1996
Rapid detection and isolation of shiga-like toxin (verocytotoxin)-producing Escherichia coli by direct testing of individual enterohemolytic colonies from washed sheep blood agar plates in the VTEC-RPLA assay.
    Journal of clinical microbiology, 1996, Volume: 34, Issue:11

    By combining the enterohemolysin test and the VTEC-RPLA test (specific for the detection of Shiga-like toxin I [SLT-I], SLT-II, and SLT-IIc), single colonies of SLT-producing Escherichia coli were found to constitute between 0.03 and 68.1% of the coliform flora in human stool cultures and were isolated and characterized within 72 to 96 h.

    Topics: Agar; Animals; Bacterial Toxins; Bacteriological Techniques; Blood; Colitis; Escherichia coli; Escherichia coli Infections; Evaluation Studies as Topic; Feces; Hemolysis; Hemolytic-Uremic Syndrome; Humans; Latex Fixation Tests; Sheep; Shiga Toxin 1

1996
Suitability of selective plating media for recovering heat- or freeze-stressed Escherichia coli O157:H7 from tryptic soy broth and ground beef.
    Applied and environmental microbiology, 1995, Volume: 61, Issue:9

    The efficacy of tryptic soy agar (TSA), modified sorbitol MacConkey agar (MSMA), modified eosin methylene blue (MEMB) agar, and modified SD-39 (MSD) agar in recovering a five-strain mixture of enterohemorrhagic Escherichia coli O157:H7 and five non-O157 strains of E. coli heated in tryptic soy broth at 52, 54, or 56 degrees C for 10, 20, and 30 min was determined. Nonselective TSA supported the highest recovery of heated cells. Significantly (P < or = 0.05) lower recovery of heat-stressed cells was observed on MSMA than on TSA, MEMB agar, or MSD agar. The suitability of MEMB agar or MSD agar for recovery of E. coli O157:H7 from heated or frozen (-20 degrees C) low- or high-fat ground beef was determined. Recovery of E. coli O157:H7 from heated ground beef was significantly (P < or = 0.05) higher on TSA than on MEMB agar, which in turn supported higher recovery than MSD agar did; MSMA was inferior. Recovery from frozen ground beef was also higher on MEMB and MSD agars than on MSMA. Higher populations were generally recovered from high-fat beef than from low-fat beef, but the relative performance of the recovery media was the same. The inability of MSMA to recover stressed cells of E. coli O157:H7 underscores the need to develop a better selective medium for enumerating E. coli O157:H7.

    Topics: Agar; Animals; Bacteriological Techniques; Cattle; Colony Count, Microbial; Culture Media; Disease Outbreaks; Escherichia coli; Escherichia coli Infections; Evaluation Studies as Topic; Foodborne Diseases; Freezing; Hot Temperature; Humans; Meat

1995
Evaluation of a new agar in Uricult-Trio for rapid detection of Escherichia coli in urine.
    Journal of clinical microbiology, 1995, Volume: 33, Issue:5

    A new commercial agar (Uricult-Trio) with 8-hydroxyquinoline-beta-glucuronide was used to assess 2,536 uropathogens for beta-glucuronidase activity typical of Escherichia coli. Included in the study were 1,807 strains of the family Enterobacteriaceae, 284 strains of nonfermentative bacilli, 345 strains of gram-positive cocci, and 100 yeast strains. In identifying E. coli, the test agar gave a sensitivity of 95.5% and a specificity of 97.2%. Fifty E. coli isolates gave negative reactions; 31 non-E. coli strains produced black colonies characteristic of E. coli. No growth of gram-positive cocci and no false-positive reactions from yeasts were observed. The recovery rate for E. coli on this agar was at least 10% higher than that on blood agar.

    Topics: Agar; Bacteriological Techniques; Bacteriuria; Diagnostic Errors; Escherichia coli; Escherichia coli Infections; Evaluation Studies as Topic; Humans; Hydroxyquinolines; Quinolines; Sensitivity and Specificity; Urinary Tract Infections; Urine

1995
[Effect of Escherichia coli on growth of Bacillus cereus].
    Roczniki Panstwowego Zakladu Higieny, 1991, Volume: 42, Issue:1

    The effect of 101 Escherichia coli strains on growth of 90 Bacillus cereus strains on solid media was investigated. Only 9 E. coli strains (in particular the colicin +-generating ones) were antagonistic towards B. cereus, giving distinct growth-inhibition zones around the colonies.

    Topics: Agar; Antibiosis; Bacillus cereus; Colony Count, Microbial; Culture Media; Diarrhea, Infantile; Escherichia coli; Escherichia coli Infections; Foodborne Diseases; Humans; In Vitro Techniques; Infant

1991
Reliability of colony characteristics on MacConkey agar to identify Escherichia coli for epidemiological investigations.
    Journal of diarrhoeal diseases research, 1990, Volume: 8, Issue:4

    Topics: Agar; Bacteriological Techniques; Epidemiologic Methods; Escherichia coli; Escherichia coli Infections; Humans

1990
Escherichia coli strains producing hydrogen sulfide in iron-agar medium.
    American journal of clinical pathology, 1974, Volume: 62, Issue:3

    Topics: Agar; Aged; Biochemical Phenomena; Biochemistry; Culture Media; Escherichia coli; Escherichia coli Infections; Female; Humans; Hydrogen Sulfide; Iron; Urinary Tract; Urinary Tract Infections

1974
[Typing E. coli isolated from birds by agar gel precipitation].
    Veterinarno-meditsinski nauki, 1974, Volume: 11, Issue:9

    Topics: Agar; Animals; Chemical Precipitation; Chickens; Escherichia coli; Escherichia coli Infections; Gels; Poultry Diseases; Serotyping; Turkeys

1974
Studies of absorption, excretion, antibacterial and clinical effect of cephalexin.
    Scandinavian journal of infectious diseases, 1970, Volume: 2, Issue:2

    Topics: Administration, Oral; Adolescent; Adult; Agar; Aged; Candidiasis; Cephalosporins; Escherichia coli; Escherichia coli Infections; Female; Haemophilus Infections; Haemophilus influenzae; Humans; Klebsiella; Klebsiella Infections; Male; Microbial Sensitivity Tests; Middle Aged; Nausea; Proteus; Proteus Infections; Staphylococcal Infections; Streptococcal Infections; Streptococcus; Streptococcus pneumoniae; Streptococcus pyogenes; Urinary Tract Infections; Vulvovaginitis

1970
[Comparative bacteriological investigations with the combination trimethoprim/sulfamethoxazole in vitro and in vivo].
    Chemotherapy, 1969, Volume: 14

    Topics: Agar; Animals; Anti-Bacterial Agents; Culture Media; Drug Resistance, Microbial; Drug Synergism; Enterobacteriaceae; Enterobacteriaceae Infections; Escherichia coli Infections; Folic Acid Antagonists; Haemophilus Infections; Meningococcal Infections; Mice; Microbial Sensitivity Tests; Pneumococcal Infections; Pyrimidines; Streptococcal Infections; Sulfamethoxazole

1969
[Oral immunization against coli enteritis with streptomycin-dependent E. coli. I. Characterization of streptomycin-dependent vaccinal strains].
    Zentralblatt fur Bakteriologie, Parasitenkunde, Infektionskrankheiten und Hygiene. 1. Abt. Medizinisch-hygienische Bakteriologie, Virusforschung und Parasitologie. Originale, 1969, Volume: 211, Issue:4

    Topics: Administration, Oral; Agar; Animals; Anti-Bacterial Agents; Bacterial Vaccines; Drug Resistance, Microbial; Enteritis; Escherichia coli; Escherichia coli Infections; Genetics, Microbial; Immunization; Mice; Mutation; Oxygen Consumption; Streptomycin; Vaccination

1969
[Occurrence of antibiotic resistent strains of E. coli in the pig].
    Zentralblatt fur Bakteriologie, Parasitenkunde, Infektionskrankheiten und Hygiene. 1. Abt. Medizinisch-hygienische Bakteriologie, Virusforschung und Parasitologie. Originale, 1968, Volume: 208, Issue:1

    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

1968
A contribution to the occurrence of E. coli O 124:K 72.
    Zentralblatt fur Bakteriologie, Parasitenkunde, Infektionskrankheiten und Hygiene. 1. Abt. Medizinisch-hygienische Bakteriologie, Virusforschung und Parasitologie. Originale, 1968, Volume: 208, Issue:3

    Topics: Adult; Agar; Antigens; Bacteriophage Typing; Bile Acids and Salts; Child; Child, Preschool; Culture Media; Czechoslovakia; Escherichia coli; Escherichia coli Infections; Feces; Female; Humans; Intestinal Diseases; Male; Serotyping; Shigella

1968