# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 2487 | 0 | 1.0000 | Clinical cases, drug resistance, and virulence genes profiling in Uropathogenic Escherichia coli. Uropathogenic Escherichia coli (UPEC) as the most important bacterial agent of urinary tract infections (UTIs) encompasses a wide treasure of virulence genes and factors. In due to this default, the aim of this research was to detect and identify some important virulence genes including cnf1, upaH, hlyA, ibeA, and cdtB in isolated UPEC pathotypes. In this research, clinical samples of urine were collected in Shahr-e-Qods, Tehran, Iran. The UPEC pathotypes were confirmed by standard biochemical tests. The DNAs of isolated bacteria were extracted. The genes of cnf1, upaH, hlyA, ibeA, and cdtB were run for multiplex PCR and gel electrophoresis. Furthermore, the antibiogram was done for the isolated UPEC strains by 11 common antibiotics. In accordance with the results, the virulence genes of cnf1, upaH, hlyA, ibeA, and cdtB were respectively recognized in 100%, 51.2%, 38.4%, 9.3%, and 0% of isolated UPEC pathotypes. In consequence, the final virulence gene profiling of the isolated UPEC strains was patterned as cnf1, cnf1-upaH, cnf1-upaH-hlyA, and cnf1-upaH-hlyA-ibeA. The chi-square tests showed no significant correlations between virulence gene profile and UTIs, between virulence gene profile and antibiotic resistance, and between virulence genes and different types of UTIs. The cnf1 virulence gene contributes in the occurrence of all types of UTIs. In contrast to cnf1, the cdtB gene was absent in the isolated UPEC strains in this investigation. The most ineffective antibiotics were recognized as Penicillin, Tetracycline, and Nalidixic acid, respectively, while Streptomycin, Chloramphenicol, and Ciprofloxacin are the best options for UTIs treatment. | 2020 | 31950434 |
| 2674 | 1 | 0.9996 | Phylogeny, virulence factors and antimicrobial susceptibility of Escherichia coli isolated in clinical bovine mastitis. The aim of this study was to identify specific phylogeny groups, virulence genes or antimicrobial resistance traits of Escherichia coli isolated in bovine mastitis associated to clinical signs, persistence of intramammary infection in the quarter and recovery from mastitis. A total of 154 E. coli isolates from bovine clinical mastitis, 144 from the acute stage and 10 from follow-up samples 3 weeks later, originating from 144 cows in 65 dairy herds in Southern Finland were investigated. Phylogeny groups and virulence genes of the isolates were determined using polymerase chain reaction, and antimicrobial susceptibility using the VetMIC™ microdilution method. In ten cows (11.8%), infection persisted, confirmed by re-isolation of the same pulsed-field gel electrophoresis type from the affected quarter at 3 weeks post-treatment. The majority of isolates, 119 (82.6%), belonged to phylogeny group A, which mainly consisted of commensal strains. Altogether 56 isolates (38.9%) had at least one virulence gene detected. Most common virulence genes detected were irp2, iucD, papC iss; genes svg, stx1, stx2, cnf1 and hlyA were not found. Combinations of virulence genes varied greatly. Forty (27.8%) of the 144 E. coli isolates showed resistance to at least one antimicrobial tested. None of the studied phylogeny groups, virulence factors or antimicrobial resistance traits was associated with clinical signs, persistence of intramammary infection or clinical recovery from mastitis. The results support the conclusion that mastitis-causing E. coli bacteria are typical commensals. | 2011 | 20729012 |
| 2333 | 2 | 0.9996 | Prevalence of USP and hlyA Genes and Association with Drug Resistance in Uropathogenic Escherichia coli Isolated from Patients in a Tertiary Hospital from Southeast China. E. coli was cultured from the urine of patients from the tertiary hospital located in Southeast China from 2017 to 2019. The species were identified, drug sensitivity test was performed, and the presence of the virulence genes USP and hlyA was determined. A total of 483 strains of E. coli were isolated, including 132 from patients with urinary tract infection (UTI). The resistance to ciprofloxacin was more common in non-UTI patients, while resistance to gentamycin was significantly higher in the UTI group. In the UTI group, the proportions of isolated bacteria with the virulence USP (40.15%) and hlyA (8.33%) genes were significantly higher than in the non-UTI group (19.60 and 2.56%, respectively). The rate of resistance of E. coli toward levofloxacin in the USP(+) group was significantly (p<0.05) higher than in the USP- group. Thus, we revealed the differences in the rate of drug resistance and prevalence of USP and hlyA between the UTI and non-UTI groups. Furthermore, the presence of the USP gene was found to be associated with greater resistance to levofloxacin. | 2022 | 36437317 |
| 2138 | 3 | 0.9996 | Isolation and molecular identification of multidrug-resistant Escherichia coli strains isolated from mastitic cows in Egypt. BACKGROUND: Mastitis is a common disease that affects the dairy sector globally because it not only impacts animal welfare but can also lead to significant financial losses. AIM: This study examined the phenotypic and genotypic profiles of the multidrug-resistant (MDR) Escherichia coli (E. coli) strains that were isolated from mastitic cows in Egypt to detect their pattern of antibiotic resistance. METHODS: Four hundred native breed lactating cows were evaluated to identify clinical and subclinical mastitis. A total of 100 mastitic milk samples (64 from clinical mastitis and 36 from subclinical mastitis) were collected for phenotypic isolation and identification of coliform bacteria. Escherichia coli isolates were identified through their morphological features, Gram staining, and biochemical tests. The identified E. coli strains were examined against various antibiotics using disk diffusion methods. All E. coli strains were analyzed for the antibiotic resistance genes Streptomycin (aadA), blaTEM, Tetracycline (tetA), Sulfonamides, and qnrA using PCR. RESULTS: Among 400 examined dairy cows, the prevalences of clinical and subclinical mastitis were 16% and 9%, respectively. Bacteriological isolation of coliform bacteria from mastitic milk samples revealed that E. coli was the most prevalent bacterium. Among 10 isolates of biochemically verified E. coli strains, 8 (80%) were MDR across 6 distinct classes of antibiotics. All recovered E. coli strains exhibited higher resistance to Amoxicillin, Cefotaxime, Sulphamethaxzole/Trimethoprim, and Tetracycline. High susceptibility was noticed to Ciprofloxaccin, Amoxicillin+Clavulinic, Streptomycin, Gentamicin, Chloramphenicol, and Colistin. The blaTEM gene was among the most common antibiotic resistance genes found in E. coli isolates (100%). Furthermore, the genotypes encoding resistance to tetA, aadA, and Sulfonamides were 50%, 40%, and 50%, respectively. CONCLUSION: MDR pathogenic E. coli strains are common in mastitic dairy cows in Egypt, and preventive actions must be implemented to avoid serious public health concerns. | 2025 | 40557079 |
| 1160 | 4 | 0.9995 | Prevalence of shiga toxins (stx1, stx2), eaeA and hly genes of Escherichia coli O157:H7 strains among children with acute gastroenteritis in southern of Iran. OBJECTIVE: To survey the prevalence severe diarrhea arising from these bacteria in children under 5 years old in Marvdasht. METHODS: In this study faecal sample from 615 children aged <5 years old who were hospitalized for gastroenteritis in Fars hospitals in Iran were collected and then enriched in Escherichia coli (E. coli) broth and modified tryptone soy broth with novobiocin media. Fermentation of sorbitol, lactose and β -glucoronidase activity of isolated strains was examined by CT-SMAC, VRBA and chromogenic media respectively. Then isolation of E. coli O157:H7 have been confirmed with the use of specific antisera and with multiplex PCR method presence of virulence genes including: stx1, stx2, eaeA, hly has been analyzed. RESULTS: E. coli O157:H7 was detected in 7 (1.14%) stool specimens. A significant difference was seen between detection rate of isolated bacteria from age groups 18-23 months and other age groups (P=0.004). Out of considered virulence genes, only 1 of the isolated strains (0.16%) the stx1 and eaeA genes were seen and also all isolated bacteria had resistance to penicillin, ampicillin and erythromycin antibiotics. CONCLUSIONS: We found that children < 2 years of age were at highest risk of infection with E. coli O157:H7. Regarding severity of E. coli O157:H7 pathogenesis, low infectious dose and lack of routine assay for detection of these bacteria in clinical laboratory, further and completed studies on diagnosis and genotyping of this E. coli O157:H7 strain has been recommended. | 2015 | 25901920 |
| 2667 | 5 | 0.9995 | Prevalence, virulence and antimicrobial resistance patterns of Aeromonas spp. isolated from children with diarrhea. BACKGROUND: Aeromonas spp. cause various intestinal and extraintestinal diseases. These bacteria are usually isolated from fecal samples, especially in children under five years old. The aim of this study was to assess the prevalence of Aeromonas spp. and their antimicrobial resistance profile in children with diarrhea referred to the Children Medical Center in Tehran, between 2013 and 2014. METHODS: A total number of 391 stool samples were collected from children with ages between 1 day and 14 years old, with diarrhea (acute or chronic), referred to the Children Hospital, Tehran, Iran, between 2013 and 2014. Samples were enriched in alkaline peptone water broth for 24 hours at 37 °C and then cultured. Suspicious colonies were analyzed through biochemical tests. Furthermore, antimicrobial susceptibility tests were carried out for the isolates. Isolates were further studied for act, ast, alt, aerA and hlyA virulence genes using polymerase chain reaction. RESULTS: In total, 12 isolates (3.1%) were identified as Aeromonas spp.; all were confirmed using the API-20E test. Of these isolates, five A. caviae (42%), four A. veronii (33%) and three A. hydrophila (25%) were identified in cases with gastroenteritis. Second to ampicillin (which was included in the growth medium used), the highest rate of antimicrobial resistance was seen against nalidixic acid and trimethoprim-sulfamethoxazole (5 isolates each, 41.6%) and the lowest rate of antimicrobial resistance was seen against gentamicin, amikacin and cefepime (none of the isolates). Results included 76.4% act, 64.7% ast, 71.5% alt, 83.3% aerA and 11.7% hlyA genes. CONCLUSION: Aeromonas spp. are important due to their role in diarrhea in children; therefore, isolation and identification of these fecal pathogens should seriously be considered in medical laboratories. Since virulence genes play a significant role in gastroenteritis symptoms caused by these bacteria, Aeromonas species that include virulence genes are potentially suspected to cause severe infections. Moreover, bacterial antimicrobial resistance is increasing, especially against trimethoprim-sulfamethoxazole and nalidixic acid. | 2016 | 27622161 |
| 2676 | 6 | 0.9995 | Characterization of commensal Escherichia coli isolates from slaughtered sheep in Mexico. INTRODUCTION: Commensal Escherichia coli is defined as bacteria without known virulence factors that could be playing a specific role in some diseases; however, they could be responsible to disseminate antimicrobial resistance genes to other microorganisms. This study aimed to characterize the commensal E. coli isolates obtained from slaughtered sheep in the central region of Mexico. METHODOLOGY: Isolates were classified as commensal E. coli when distinctive genes related to diarrheagenic pathotypes (stx1, stx2, eae, bfp, LT, stp, ipaH, and aggR) were discarded by PCR. Identification of serotype, phylogenetic group, and antimicrobial resistance was also performed. RESULTS: A total of 41 isolates were characterized. The phylogenetic groups found were B1 in 37 isolates (90.2%), A in 2 (4.8%), and 1 isolate (2.4%) for C and D groups. Serotypes associated with diarrhea in humans (O104:H2 and O154:NM) and hemolytic uremic syndrome (O8:NM) were detected. Thirty-three isolates (80%) were resistant to ceftazidime, 23 (56%), to tetracycline 8 (19.5%) to ampicillin, and 1 to amikacin. Six isolates (14.6%) were multidrug-resistant. CONCLUSIONS: This study provides new information about commensal E. coli in slaughtered sheep, high percentages of resistance to antibiotics, and different profiles of antimicrobial resistance were found, their dissemination constitute a risk factor towards the consuming population. | 2021 | 34898507 |
| 2325 | 7 | 0.9995 | Association of Virulence Genes with Antibiotic Resistance in Pakistani Uropathogenic E. coli Isolates. BACKGROUND: Escherichia coli various strains can cause alarmingly serious infections. Countries like Pakistan harbour the class of bacteria with one of the highest rates of resistance, but very little has been done to explore their genetic pool. OBJECTIVES: This study was designed to find out the frequency of virulence genes of Uropathogenic E. coli and their association with antibiotic resistance along with the evolutionary adaptation of the selected gene through the phylogenetic tree. METHODS: Isolates from 120 urinary tract infected patients were collected. Antibiotic sensitivity was detected by the disk diffusion method and DNA extraction was done by the boiling lysis method followed by PCR-based detection of virulence genes. The final results were analysed using the chi-square test. RESULTS: The isolates were found to be least susceptible to nalidixic acid, followed by ampicillin, cotrimoxazole, cefotaxime, ciprofloxacin, aztreonam, amoxicillin, gentamycin, nitrofurantoin and imipenem. The iucC was the most common virulence gene among the resistant isolates. About 86% of the collected samples were found to be multi-drug resistant. Statistical analysis revealed a significant association between the iucC gene and resistance to ampicillin (P=0.03) and amoxicillin (P=0.04), and also between fimH and resistance to aztreonam (P=0.03). CONCLUSION: This study unravels the uncharted virulence genes of UPEC in our community for the very first time. We report a high frequency of the iucC and fimH virulence genes. This, along with their positive association with resistance to beta-lactam antibiotics in the studied community, indicates their important role in the development of complicated UTIs. | 2020 | 32238138 |
| 2157 | 8 | 0.9995 | Prevalence and antibiotic resistance pattern of bacteria isolated from urinary tract infections in Northern Iran. BACKGROUND: This study aimed to investigate the bacteria associated with urinary tract infection (UTI) and antibiotic susceptibility pattern of the isolates during 2013-2015 in Northern Iran. MATERIALS AND METHODS: Overall 3798 patients with clinical symptoms of UTI were subjected as samples, and they were cultured and pure isolated bacteria were identified using biochemical tests and subjected to antibiogram assessment using disc diffusion method. RESULTS: Totally, 568 (14.96%) from 3798 patients had positive UTI. Four hundred and ninety-seven (87.5%) from 568 isolated bacteria were resistant to at least one antibiotic. Escherichia coli, Staphylococcus spp., and Pseudomonas spp. were the most prevalent bacteria. Isolated bacteria indicated the highest antibiotic resistance to methicillin (76.06%) and ampicillin (89.29%) and also revealed the most sensitivity to imipenem (99.1%) and amikacin (91.57%). Statistical analysis of the resistance pattern trend during 3 years indicated the insignificant increase (P > 0.05) in antibiotic resistance of the isolates. CONCLUSION: The results of this study revealed a great concern for emerging UTI-related multidrug-resistant strains of bacteria causing UTI in Iran. | 2017 | 29026424 |
| 2410 | 9 | 0.9995 | Phenotypic and molecular characterization of antimicrobial resistance in Trueperella pyogenes strains isolated from bovine mastitis and metritis. BACKGROUND: Trueperella pyogenes is one of the most clinically imperative bacteria responsible for severe cases of mastitis and metritis, particularly in postpartum dairy cows. The bacterium has emergence of antibiotic resistance and virulence characters. The existing research was done to apprise the phenotypic and genotypic evaluation of antibiotic resistance and characterization of virulence factors in the T. pyogenes bacteria of bovine mastitis and metritis in postpartum cows. METHODS: Two-hundred and twenty-six bovine mastitic milk and 172 uterine swabs were collected and transferred to laboratory. Samples were cultured and T. pyogenes isolates were subjected to disk diffusion and DNA extraction. Distribution of virulence and antibiotic resistance genes was studied by PCR. RESULTS: Thirty-two out of 226 (14.15%) mastitic milk and forty-one out of 172 (23.83%) uterine swab samples were positive for T. pyogenes. Isolates of mastitic milk harbored the highest prevalence of resistance toward gentamicin (100%), penicillin (100%), ampicillin (90.62%), amoxicillin (87.50%) and trimethoprim-sulfamethoxazole (87.50%), while those of metritis harbored the highest prevalence of resistance toward ampicillin (100%), amoxicillin (100%), gentamicin (97.56%), penicillin (97.56%) and cefalexin (97.56%). AacC, aadA1, aadA2 and tetW were the most generally perceived antibiotic resistance genes. All bacteria harbored plo (100%) and fimA (100%) virulence factors. NanP, nanH, fimC and fimE were also the most generally perceived virulence factors. CONCLUSIONS: All bacteria harbored plo and fimA virulence factors which showed that they can use as specific genetic markers with their important roles in pathogenicity of T. pyogenes bacteria. Phenotypic pattern of antibiotic resistance was confirmed by genotypic characterization of antibiotic resistance genes. | 2019 | 31881834 |
| 2974 | 10 | 0.9995 | Diversity of Virulence Genes in Multidrug Resistant Escherichia coli from a Hospital in Western China. BACKGROUND: Escherichia coli strains are the most commonly isolated bacteria in hospitals. The normally harmless commensal E. coli can become a highly adapted pathogen, capable of causing various diseases both in healthy and immunocompromised individuals, by acquiring a combination of mobile genetic elements. Our aim was to characterize E. coli strains from a hospital in western China to determine their virulence and antimicrobial resistance potential. METHODS: A total of 97 E. coli clinical isolates were collected from the First Affiliated Hospital of Chengdu Medical College from 2015 to 2016. Microbiological methods, PCR, and antimicrobial susceptibility tests were used in this study. RESULTS: The frequency of occurrence of the virulence genes fimC, irp2, fimH, fyuA, lpfA, hlyA, sat, and cnf1 in the E. coli isolates was 93.81, 92.78, 91.75, 84.54, 41.24, 32.99, 28.86, and 7.22%, respectively. Ninety-five (97.9%) isolates carried two or more different virulence genes. Of these, 44 (45.4%) isolates simultaneously harbored five virulence genes, 24 (24.7%) isolates harbored four virulence genes, and 17 (17.5%) isolates harbored six virulence genes. In addition, all E. coli isolates were multidrug resistant and had a high degree of antimicrobial resistance. CONCLUSION: These results indicate a high frequency of occurrence and heterogeneity of virulence gene profiles among clinical multidrug resistant E. coli isolates. Therefore, appropriate surveillance and control measures are essential to prevent the further spread of these isolates in hospitals. | 2019 | 31824179 |
| 2335 | 11 | 0.9995 | Isolation, identification, molecular typing, and drug resistance of Escherichia coli from infected cattle and sheep in Xinjiang, China. BACKGROUND: Escherichia coli infections are common in Xinjiang, a major region of cattle and sheep breeding in China. Therefore, strategies are required to control E. coli. The aim of this study was to investigate the phylogenetic groups, virulence genes, and antibiotic resistance characteristics of E. coli isolates. METHODS: In this study, 116 tissue samples were collected from the organs of cattle and sheep that were suspected of having E. coli infections between 2015 and 2019. Bacteria in the samples were identified using a biochemical identification system and amplification of 16S rRNA, and the phylogenetic groupings of E. coli isolates were determined by multiplex polymerase chain reactions. In addition, PCR detection and analysis of virulence factors, antibiotic resistance genes, and drug-resistant phenotypes of E. coli isolates were performed. RESULTS: A total of 116 pathogenic E. coli strains belonging to seven phylogenetic groups were isolated, with the majority of isolates in groups A and B1. Among the virulence genes, curli-encoding crl had the highest detection rate of 97.4%, followed by hemolysin-encoding hlyE with the detection rate of 94.82%. Antimicrobial susceptibility test results indicated that the isolates had the highest rates of resistance against streptomycin (81.9%). CONCLUSION: These characteristics complicate the prevention and treatment of E. coli-related diseases in Xinjiang. | 2023 | 36977209 |
| 2391 | 12 | 0.9995 | Antimicrobial resistance and presence of virulence factor genes in Arcanobacterium pyogenes isolated from the uterus of postpartum dairy cows. Arcanobacterium pyogenes is considered the most significant bacterium involved in the pathogenesis of metritis in cattle. Infections caused by antimicrobial-resistant bacteria are a great challenge in both human and veterinary medicine. The purpose of this study was to present an overview of antimicrobial resistance in A. pyogenes isolated from the uteruses of postpartum Holstein dairy cows and to identify virulence factors. Seventy-two A. pyogenes isolates were phenotypically characterized for antimicrobial resistance to amoxicillin, ampicillin, ceftiofur, chloramphenicol, florfenicol, oxytetracycline, penicillin, spectinomycin, streptomycin and tetracycline by the broth microdilution method. Presence of virulence factor genes of A. pyogenes was investigated. Isolates exhibited resistance to all antimicrobial agents tested; high levels of resistance were found to amoxicillin (56.9%); ampicillin (86.1%), chloramphenicol (100%), florfenicol (59.7%), oxytetracycline (54.2%), penicillin (86.1%) and tetracycline (50%). Of all isolates, 69 (95.8%) were resistant to at least 2 of the antimicrobial agents tested and multidrug resistance (resistant to at least 3 antimicrobials) was observed in 64 (88.9%) of the A. pyogenes isolates. The major multidrug resistance profile was found for chloramphenicol-ampicillin-penicillin-florfenicol-amoxicillin-tetracycline, which was observed in 21 (29.2%) multidrug resistant isolates. No isolate was resistant to all nine antimicrobial agents tested but four isolates (5.6%) were resistant to eight antimicrobials. The information highlights the need for prudent use of specific antimicrobial agents. All four virulence factor genes occurred in isolates from normal puerperium and clinical metritis; however, the fimA gene was present in significantly higher frequency in isolates from metritis cows. | 2010 | 20346602 |
| 2155 | 13 | 0.9994 | Resistance Profiles and Virulence Factors of Enteric Escherichia coli in Chronic Kidney Disease Patients at Laquintinie Hospital in Douala, Cameroon. Escherichia coli is commonly found in human feces and is the most prevalent resistant microorganism in patients with chronic kidney disease. Several studies demonstrated that virulence factors were a major cause of the emergence of pathogenic strains of E. coli. This study's objective was to determine the antibiotic resistance profile, detect virulence factors, and assess the prevalence of carriage of extended-spectrum beta-lactamase (ESBL) genes in fecal E. coli isolates obtained from chronic kidney disease patients. This research was carried out in Laquintinie Hospital of Douala between January 2022 and December 2023. In total, 458 patients with (n = 197) or without (n = 261) chronic kidney disease and suffering from gastroenteritis constituted the total population. E. coli isolates were obtained by using eosin methylene blue (EMB) agar and identified by the API 20E gallery system. The Kirby-Bauer method was used to determine the isolates' antibiotic resistance profile. The simplex polymerase chain reaction (PCR) served to detect virulence factors and resistance genes. It appeared that all antibiotics tested, except nalidixic acid, presented a significant resistance (p < 0.05) in chronic kidney disease patients contrasted to patients without chronic kidney disease. The antibiotic susceptibility testing revealed a high level of resistance to amoxicillin (94.5%), amoxicillin-clavulanic acid (79.5%), trimethoprim/sulfamethoxazole (69.9%), and ofloxacin (65.8%) in patients with chronic kidney disease. E. coli isolates showed (p < 0.001) a significantly high rate of multidrug resistance phenotype in chronic kidney disease patients (74.0%) as compared to patients without chronic kidney disease (35.7%). According to the virulence genes detected, the most prevalent pathotype of E. coli was the enteropathogenic E. coli (40.8%; n = 40), followed by enterotoxigenic E. coli (29.6%; n = 29) and shiga toxin-producing E. coli (29.6%; n = 29). The screening of resistance genes in pathotypes of E. coli has demonstrated that bla (TEM) (76.5%; n = 75) and bla (CTX-M) (75.5%; n = 74) were the more frequent ESBL resistance genes encountered. This study showed that a high rate of resistance, multidrug resistance, and a high frequency of enteropathogenic E. coli and ESBL resistance genes in E. coli were most often found in chronic kidney disease patients. This high level of enteric multidrug-resistant E. coli in chronic kidney disease patients exposes them to hazardous antibiotic treatment and serious public health issues. | 2025 | 40980185 |
| 1164 | 14 | 0.9994 | The distribution of beta lactamase genes in Escherichia coli phylotypes isolated from diarrhea and UTI cases in northwest Iran. BACKGROUND: Pathogenic Escherichia coli strains are a common cause of intestinal and extra-intestinal infections, especially in developing countries. Extended spectrum beta-lactamases (ESBLS), a heterogeneous group of plasmid-encoded beta-lactamases, are common throughout the world. OBJECTIVES: The aim of the present study was to determine the phenotypic and genotypic characteristics of ESBLS produced by E. coli isolates taken from patients with diarrhea and urinary tract infections (UTI) in northwest Iran. MATERIAL AND METHODS: A total of 132 E. coli isolates (92 isolates from UTI and 40 isolates from diarrheic cases) were recovered and confirmed by biochemical tests. The isolates were examined for blaTEM and blaSHV genes and phylogenetic background by two multiplex PCR assays. The isolates were tested for antibiotic susceptibility against nine antibiotic agents by the disk diffusion method. RESULTS: The phylogenetic analysis showed that the UTI isolates mostly fell into phylo-group B2, followed by D, while the diarrheic isolates belonged to phylo-groups D and A. Out of 92 UTI isolates, 29.3% and 17.4% possessed blaTEM and blaSHV genes, respectively. Ten diarrheic isolates were positive for blaTEM, two isolates possessed the blaSHV gene, and one isolate was positive for both genes. The UTI isolates that were positive for blaTEM and blaSHV genes mostly belonged to phylo-groups D and B2, whereas the diarrhea isolates were in phylo-groups D and A. Phylogenetic group D isolates have an accumulation of ESBLS genes in the diarrheic and UTI isolates. In both the UTI and diarrhea isolates, the maximum rate of resistance was against cefazolin, and the minimum rate of resistance was against nitrofurantoin. Twenty-four antibiotic resistance patterns were observed among the isolates. The amikacin, ciprofloxacin, cefotaxime, cefuroxime, cefazolin, gentamicin, nalidixic acid and trimethoprim/sulfamethoxazole resistance pattern was the most prevalent in the isolates that belonged to phylo-group D. CONCLUSIONS: The correct choice of effective antibiotic policy is needed to limit the spread of antibiotic resistance in bacteria. | 2014 | 25166436 |
| 2668 | 15 | 0.9994 | Genotyping and distribution of putative virulence factors and antibiotic resistance genes of Acinetobacter baumannii strains isolated from raw meat. BACKGROUND: Acinetobacter baumannii strains with multiple antimicrobial resistance are primarily known as opportunistic nosocomial bacteria but they may also be regarded as emerging bacterial contaminants of food samples of animal origin. Here we aimed to study the molecular characteristics of the A. baumanni strains isolated from raw meat samples. METHODS: A total of 22 A. baumanni strains were isolated from 126 animal meat samples and were genotyped by ERIC-PCR method and by PCR detection of their virulence and antimicrobial resistance determinants. A. baumannii strains with 80% and more similarities were considered as one cluster. RESULTS: Sixteen different genetic clusters were found amongst the 22 A. baumanni strains. Of the 22 strains, 12 (54.54%) had similar genetic cluster. A. baumannii strains exhibited the highest percentage of resistance against tetracycline (90.90%), trimethoprim (59.09%), cotrimoxazole (54.54%) and gentamicin (50.00%). TetA (81.81%), tetB (72.72%), dfrA1 (63.63%), aac(3)-IV (63.63%), sul1 (63.63%) and aadA1 (45.45%) were the most commonly detected antibiotic resistance genes. FimH (81.81%), afa/draBC (63.63%), csgA (63.63%), cnf1 (59.09%), cnf2 (54.54%) and iutA (50.00%) were the most commonly detected virulence factors. A. baumannii strains isolated from the chicken meat samples had the highest similarities in the genetic cluster. CONCLUSIONS: A. baumannii strains with similar genetic cluster (ERIC-Type) had the same prevalence of antibiotic resistance, antibiotic resistance genes and virulence factors. Genetic cluster of the A. baumannii strains is the main factor affected the similarities in the genotypic and phenotypic properties of the A. baumannii strains. | 2018 | 30323923 |
| 2698 | 16 | 0.9994 | EHEC, EPEC, and ETEC strains and their antibiotic resistance in drinking and tap water samples. BACKGROUND: Investigating of the presence of Enterohemorrhagic E. coli (EHEC), Enterotoxigenic E. coli (ETEC), Enteropathogenic E. coli (EPEC) strains and their antibiotic resistance in natural spring waters and tap waters from two university hospitals, in Istanbul. METHODS: E. coli strains isolated from water samples were identified by polymerase chain reaction (PCR) method using stx-1, stx-2, eaeA genes specific for EHEC; eaeA, bfp genes specific for EPEC and lt, st genes specific for ETEC. Antibiotic susceptibility tests were done according to the Kirby-Bauer method using The Clinical and Laboratory Standards Institute (CLSI) criteria. RESULTS: E. coli strains were isolated from only five (2.7%) out of 184 water samples. Only one of the 36 E. coli strains isolated from these five water samples was found to be extended spectrum beta lactamase (ESBL) positive. According to PCR, ten E. coli strains isolated from one drinking water were identified as ETEC. Other than E. coli strains, coliforms and non-fermentative Gram negative bacteria were also isolated from waters. It was shown that 60 (81.1%) of these 74 strains isolated, other than E. coli, were found to be multiple resistant. CONCLUSIONS: Contrary to our expectations, it has been shown that natural spring waters (drinking waters) can be much more contaminated with fecal bacteria when compared with tap waters. The presence of pathogenic E. coli strains and antibiotic resistant Gram negative bacteria especially in drinking waters emphasize the importance of these types of studies. | 2015 | 25807645 |
| 2675 | 17 | 0.9994 | Prevalence and Zoonotic Risk of Multidrug-Resistant Escherichia coli in Bovine Subclinical Mastitis Milk: Insights Into the Virulence and Antimicrobial Resistance. The emergence of antibiotic-resistant microorganisms has made antimicrobial resistance a global issue, and milk is a potential source for the propagation of resistant bacteria causing zoonotic diseases. Subclinical mastitis (SCM) cases, often overlooked and mixed with normal milk in dairy farms, frequently involve E. coli, which can spread through contaminated milk. We conducted this study to determine the prevalence of virulence genes, antibiotic resistance genes (ARGs), antimicrobial susceptibility, and the genetic relatedness of multidrug-resistant (MDR) Shiga toxin-producing E. coli (STEC) isolated from SCM milk. SCM-positive bovine milk was subjected to E. coli detection using cultural, biochemical, and molecular methods. Further, we detected STEC virulence genes including stx1, stx2, and eaeA. STEC isolates were tested for ARGs including blaSHV, CITM, tetA, and aac(3)-IV, and underwent antimicrobial susceptibility tests. Moreover, we performed a phylogenetic analysis of the stx1 gene of MDR-STEC. SCM was detected in 47.2% of milk samples of which 50.54% were E. coli positive. About 17.20% of E. coli isolates contained STEC virulence genes, and stx2 was the most prevalent. Moreover, all STEC isolates harbored at least one of the ARGs, while about 43.75% of the isolates carried multiple ARGs. Additionally, all the STEC isolates showed multidrug resistance, and were found to be fully resistant against amoxicillin, followed by ampicillin (87.50%) and gentamycin (75%); and were mostly sensitive to aztreonam (81.25%) and meropenem (68.75%). In phylogeny analysis, the stx1 gene of isolated MDR-STEC showed close relatedness with disease-causing non-O157 and O157 strains of different sources including cattle, humans, and food. | 2025 | 39816483 |
| 2137 | 18 | 0.9994 | High prevalence of antibiotic resistance and biofilm formation in Salmonella Gallinarum. BACKGROUND AND OBJECTIVES: Antibiotic resistance is an indicator of the passively acquired and circulating resistance genes. Salmonella Gallinarum significantly affects the poultry food industry. The present study is the first study of the S. Gallinarum biofilm in Iran, which is focused on the characterization of the S. Gallinarum serovars and their acquired antibiotic resistance genes circulating in poultry fields in central and northwestern Iran. MATERIALS AND METHODS: Sixty isolates of S. Gallinarum serovar were collected from feces of live poultry. The bacteria were isolated using biochemical tests and confirmed by Multiplex PCR. Biofilm formation ability and the antibacterial resistance were evaluated using both phenotypic and genotypic methods. The data were analyzed using SPSS software. RESULTS: According to Multiplex PCR for ratA, SteB, and rhs genes, all 60 S. Gallinarum serovars were Gallinarum biovars. In our study, the antibiotic resistance rate among isolated strains was as follows: Penicillin (100%), nitrofurantoin (80%), nalidixic acid (45%), cefoxitin (35%), neomycin sulfate (30%), chloramphenicol (20%), and ciprofloxacin (5%). All isolates were susceptible to imipenem, ertapenem, ceftriaxone, ceftazidime, and ceftazidime+clavulanic acid. All sixty isolates did not express the resistance genes IMP, VIM, NDM, DHA, bla(OXA48), and qnrA. On the other hand, they expressed GES (85%), qnrB (75%), Fox M (70%), SHV (60%), CITM (20%), KPC (15%), FOX (10%), MOXM (5%), and qnrS (5%). All S. Gallinarum isolates formed biofilm and expressed sdiA gene. CONCLUSION: Considering that the presence of this bacteria is equal to the death penalty to the herd, the distribution of resistance genes could be a critical alarm for pathogen monitoring programs in the region. This study showed a positive correlation between biofilm formation and 50% of tested resistance genes. Also, it was found that the most common circulating S. gallinarum biovars are multidrug-resistant. | 2023 | 37941876 |
| 2411 | 19 | 0.9994 | Genomic characterisation, detection of genes encoding virulence factors and evaluation of antibiotic resistance of Trueperella pyogenes isolated from cattle with clinical metritis. Trueperella pyogenes is one of the most important microorganisms causing metritis in post-partum cattle. Co-infection with other bacterial species such as Escherichia coli or Fusobacterium necrofurom increases the severity of the disease and the persistence of bacteria in utero. The aim of this study was to investigate the frequency of T. pyogenes strains, and their virulence and antimicrobial resistant profiles in metritis cases. The study was carried out on 200 samples obtained from metritis discharges of postpartum cattle on 18 farms around Tehran, Iran. Sixty-five T. pyogenes isolates (32.5%) were identified, of which 16 isolates were detected as pure cultures and the other 49 isolates from cultures most commonly mixed with E. coli or F. necrofurom. In terms of diversity in biochemical characteristic of T. pyogenes strains, 8 different biotypes were identified among the isolates. Single or multi antimicrobial resistance was observed in 48 isolates (73.9%), which was mostly against trimethoprim sulfamethoxazole, azithromycin, erythromycin and streptomycin. The tetracycline resistance gene tetW and macrolide resistance genes ermB and ermX were detected in 30, 18 and 25 isolates, respectively. In the screening of genes encoding virulence factors, fimA and plo genes were identified in all tested isolates. Genes encoding nanP, nanH, fimC, fimG, fimE and cbpA were detected in 50, 54, 45, 40, 50 and 37 of isolates, respectively. Thirteen different genotypes were observed in these T. pyogenes isolates. A significant association between clonal types and virulence factor genes, biochemical profile, CAMP test result, severity of the disease and sampling time was detected. | 2018 | 30066209 |