# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 1167 | 0 | 1.0000 | Investigating the virulence-associated genes and antimicrobial resistance of Escherichia fergusonii Isolated from diseased ostrich chicks. This study investigates the presence of virulence-associated genes and antimicrobial resistance (AMR) in Escherichia fergusonii isolates obtained from ostrich chicks. A total of 287 isolates were recovered from 106 fecal samples from ostrich chicks suffering from diarrhea and subjected to molecular identification and biochemical characterization. E. fergusonii was detected in 10 samples (9.4 %) using two PCR-detection protocols. Notably, the isolates lacked various virulence genes commonly associated with pathogenic E. coli including elt, est, stx, eae, ehly, cdt, iss, iutA, iroN, hlyA, ompT, except for one isolate harboring the astA gene. Antimicrobial susceptibility testing revealed that all isolates were susceptible to ciprofloxacin, while high resistance was observed against amoxicillin clavulanate (AMC), trimethoprim-sulfamethoxazole (SXT), and doxycycline (D). Moreover, eight isolates displayed multidrug resistance (MDR) and four exhibited resistance to 9-11 antimicrobials. The most frequent resistance gene was sul2, which was present in all isolates; the other resistance genes detected consisted of int1 (4/10), int2 (3/10), bla(CMY) (2/10), and qnrS, bla(TEM), bla(CMY), bla(CTX-M), and flo each were detected only in one E. fergusonii Isolate. Plasmid replicon typing identified the presence of I1 (7/10), N (5/10), and Y (1/10). This study provides valuable insights into the virulence and antimicrobial resistance of E. fergusonii isolates from ostrich chicks, highlighting the complexity of antimicrobial resistance mechanisms exhibited by these bacteria. Further research is essential to understand the transmission dynamics and clinical implications of these findings in veterinary and public health settings. | 2024 | 39168034 |
| 1152 | 1 | 0.9998 | Gut Commensal Escherichia coli, a High-Risk Reservoir of Transferable Plasmid-Mediated Antimicrobial Resistance Traits. BACKGROUND: Escherichia coli (E. coli), the main human gut microorganism, is one of the evolved superbugs because of acquiring antimicrobial resistance (AMR) determinants via horizontal gene transfer (HGT). PURPOSE: This study aimed to screen isolates of gut commensal E. coli from healthy adult individuals for antimicrobial susceptibility and plasmid-mediated AMR encoding genes. METHODS: Gut commensal E. coli bacteria were isolated from fecal samples that were taken from healthy adult individuals and investigated phenotypically for their antimicrobial susceptibility against diverse classes of antimicrobials using the Kirby Bauer disc method. PCR-based molecular assays were carried out to detect diverse plasmid-carried AMR encoding genes and virulence genes of different E. coli pathotypes (eaeA, stx, ipaH, est, elt, aggR and pCVD432). The examined AMR genes were β-lactam resistance encoding genes (bla (CTX-M1), bla (TEM), bla (CMY-2)), tetracycline resistance encoding genes (tetA, tetB), sulfonamides resistance encoding genes (sul1, sulII), aminoglycoside resistance encoding genes (aac(3)-II, aac(6')-Ib-cr) and quinolones resistance encoding genes (qnrA, qnrB, qnrS). RESULTS: PCR results revealed the absence of pathotypes genes in 56 isolates that were considered gut commensal isolates. E. coli isolates showed high resistance rates against tested antimicrobial agents belonging to both β-lactams and sulfonamides (42/56, 75%) followed by quinolones (35/56, 62.5%), tetracyclines (31/56, 55.4%), while the lowest resistance rate was to aminoglycosides (24/56, 42.9%). Antimicrobial susceptibility profiles revealed that 64.3% of isolates were multidrug-resistant (MDR). High prevalence frequencies of plasmid-carried AMR genes were detected including bla (TEM) (64%) sulI (60.7%), qnrA (51.8%), aac(3)-II (37.5%), and tetA (46.4%). All isolates harbored more than one gene with the most frequent genetic profile among isolates was bla (TEM)-bla (CTX-M1-like)-qnrA-qnrB-tetA-sulI. CONCLUSION: Results are significant in the evaluation of plasmid-carried AMR genes in the human gut commensal E. coli, suggesting a potential human health risk and the necessity of strict regulation of the use of antibiotics in Egypt. Commensal E. coli bacteria may constitute a potential reservoir of AMR genes that can be transferred to other bacterial species. | 2022 | 35321080 |
| 1307 | 2 | 0.9997 | Identification of shiga toxin and intimin coding genes in Escherichia coli isolates from pigeons (Columba livia) in relation to phylotypes and antibiotic resistance patterns. Shiga toxin-producing Escherichia coli (STEC) strains are responsible for outbreaks of human intestinal diseases worldwide. Pigeons are distributed in public areas and are potential reservoirs for pathogenic bacteria. One hundred fifty-four fresh fecal samples were obtained from trapped pigeons in southeast of Iran and were cultured for isolation of E. coli. The isolates were examined to determine the prevalence of stx1, stx2, and eae genes, antimicrobial resistance, and their phylotypes. The confirmed E. coli isolates (138) belong to four phylogenetic groups: A (54.34%), B1 (34.05%), B2 (3.62%), and D (7.79%). Thirteen (9.42%) isolates were positive for one of the examined genes. Eight isolates (5.79%) were positive for eae, four (2.89%) for stx2, and one isolate (1.44%) for stx1 gene. Phylotyping assays showed that eight eae-positive isolates fall into three phylogroups; A (three isolates), B1 (three isolates), and D (two isolates), whereas four stx2-positive isolates belonged to the A (three isolates) and D (one isolate) groups. The stx1-positive isolate belonged to phylogroup A. One hundred six isolates (76.81%) showed resistance to at least one of the selected antibacterial agents. The maximum resistance rate was against oxytetracycline (73.91%), and the minimum was against flumequine (2.17%). Twenty different patterns of drug resistance were observed. According to the results, pigeons could be considered as carriers of STEC strains. However, E. coli isolates of pigeon feces increase the potential of these birds to act as a reservoir of multiple antibiotic resistant bacteria. | 2012 | 22105907 |
| 1308 | 3 | 0.9997 | Antimicrobial resistance genes and virulence gene encoding intimin in Escherichia coli and Enterococcus isolated from wild rabbits (Oryctolagus cuniculus) in Tunisia. The spread of antimicrobial-resistant bacteria in wildlife must be viewed as a major concern with serious implications for human and animal health. Escherichia coli and enterococcal isolates were recovered from faecal samples of 49 wild rabbits (Oryctolagus cuniculus) on specific media and were characterised using biochemical and molecular tests. For all isolates, antimicrobial susceptibility testing was performed, and resistance genes were detected by PCR. Molecular typing of isolates was carried out by pulsed-field gel-electrophoresis, and E. coli strains were also tested for the presence of intimin (eae) gene characteristic of rabbit enteropathogenic E. coli. A total of 34 E. coli and 36 enterococci [E. hirae (52.8%) and E. faecalis (47.2%)] were obtained. For E. coli, resistance to tetracycline (94%), streptomycin (62%), ciprofloxacin (47%), trimethoprim-sulphamethoxazole (35%) and chloramphenicol (6%) was observed. Resistance to third-generation cephalosporins was detected in one E. coli strain that carried the bla(CMY-2) and bla(TEM-1) genes. Class 1 integrons were detected in eight isolates. For enterococci, resistance to tetracycline (63.9%), erythromycin (30.5%), streptomycin (18.2%), and chloramphenicol (5.5%) was detected. The tet(M)+tet(L), erm(B) and ant (6)-Ia genes were identified in thirteen, seven and three resistant Enterococcus strains, respectively. Molecular typing showed a high diversity among our strains. Wild rabbits could represent a reservoir of E. coli, and enterococci carrying antimicrobial resistance genes and E. coli additionally carrying the eae gene of enteropathogenic pathotypes could both contaminate the environment. our finding seems to represent the first report of eae-positive E. coli in wild rabbits. | 2019 | 31842593 |
| 1310 | 4 | 0.9997 | Antimicrobial Resistance of Escherichia fergusonii Isolated from Broiler Chickens. The objective of this study was to investigate the antibiotic resistance of Escherichia fergusonii isolated from commercial broiler chicken farms. A total of 245 isolates from cloacal and cecal samples of 28- to 36-day-old chickens were collected from 32 farms. Isolates were identified using PCR, and their susceptibility to 16 antibiotics was determined by disk diffusion assay. All isolates were susceptible to meropenem, amikacin, and ciprofloxacin. The most common resistances were against ampicillin (75.1%), streptomycin (62.9%), and tetracycline (57.1%). Of the 184 ampicillin-resistant isolates, 127 were investigated using a DNA microarray carrying 75 probes for antibiotic resistance genetic determinants. Of these 127 isolates, the β-lactamase blaCMY2, blaTEM, blaACT, blaSHV, and blaCTX-M-15 genes were detected in 120 (94.5%), 31 (24.4%), 8 (6.3%), 6 (4.7%), and 4 (3.2%) isolates, respectively. Other detected genes included those conferring resistance to aminoglycosides (aadA1, strA, strB), trimethoprims (dfrV, dfrA1), tetracyclines (tetA, tetB, tetC, tetE), and sulfonamides (sul1, sul2). Class 1 integron was found in 35 (27.6%) of the ampicillin-resistant isolates. However, our data showed that the tested E. fergusonii did not carry any carbapenemase blaOXA genes. Pulsed-field gel electrophoresis revealed that the selected ampicillin-resistant E. fergusonii isolates were genetically diverse. The present study indicates that the monitoring of antimicrobial-resistant bacteria should include enteric bacteria such as E. fergusonii, which could be a reservoir of antibiotic resistance genes. The detection of isolates harboring extended-spectrum β-lactamase genes, particularly blaCTX-M-15, in this work suggests that further investigations on the occurrence of such genes in broilers are warranted. | 2016 | 27296596 |
| 1313 | 5 | 0.9997 | Molecular epidemiology of ceftiofur-resistant Escherichia coli isolates from dairy calves. Healthy calves (n = 96, 1 to 9 weeks old) from a dairy herd in central Pennsylvania were examined each month over a five-month period for fecal shedding of ceftiofur-resistant gram-negative bacteria. Ceftiofur-resistant Escherichia coli isolates (n = 122) were characterized by antimicrobial resistance (disk diffusion and MIC), serotype, pulsed-field gel electrophoresis subtypes, beta-lactamase genes, and virulence genes. Antibiotic disk diffusion assays showed that the isolates were resistant to ampicillin (100%), ceftiofur (100%), chloramphenicol (94%), florfenicol (93%), gentamicin (89%), spectinomycin (72%), tetracycline (98%), ticarcillin (99%), and ticarcillin-clavulanic acid (99%). All isolates were multidrug resistant and displayed elevated MICs. The E. coli isolates belonged to 42 serotypes, of which O8:H25 was the predominant serotype (49.2%). Pulsed-field gel electrophoresis classified the E. coli isolates into 27 profiles. Cluster analysis showed that 77 isolates (63.1%) belonged to one unique group. The prevalence of pathogenic E. coli was low (8%). A total of 117 ceftiofur-resistant E. coli isolates (96%) possessed the bla(CMY2) gene. Based on phenotypic and genotypic characterization, the ceftiofur-resistant E. coli isolates belonged to 59 clonal types. There was no significant relationship between calf age and clonal type. The findings of this study revealed that healthy dairy calves were rapidly colonized by antibiotic-resistant strains of E. coli shortly after birth. The high prevalence of multidrug-resistant nonpathogenic E. coli in calves could be a significant source of resistance genes to other bacteria that share the same environment. | 2006 | 16751500 |
| 1199 | 6 | 0.9997 | Multi-drug resistant pathogenic bacteria in the gut of young children in Bangladesh. BACKGROUND: The gut of human harbors diverse commensal microbiota performing an array of beneficial role for the hosts. In the present study, the major commensal gut bacteria isolated by culturing methods from 15 children of moderate income families, aged between 10 and 24 months, were studied for their response to different antibiotics, and the molecular basis of drug resistance. RESULTS: Of 122 bacterial colonies primarily selected from Luria-Bertani agar, bacterial genera confirmed by analytical profile index (API) 20E(®) system included Escherichia as the predominant (52%) organism, followed by Enterobacter (16%), Pseudomonas (12%), Klebsiella (6%), Pantoea (6%), Vibrio (3%), and Citrobacter (3%); while Aeromonas and Raoultella were identified as the infrequently occurring genera. An estimated 11 and 22% of the E. coli isolates carried virulence marker genes stx-2 and eae, respectively. Antimicrobial susceptibility assay revealed 78% of the gut bacteria to be multidrug resistant (MDR) with highest resistance to erythromycin (96%), followed by ampicillin (63%), tetracycline (59%), azithromycin (53%), sulfamethoxazole-trimethoprim (43%), cefixime (39%), and ceftriaxone (33%). PCR assay results revealed 56% of the gut bacteria to possess gene cassette Class 1 integron; while 8, 17.5 and 6% of the strains carried tetracycline resistance-related genes tetA, tetB, and tetD, respectively. The macrolide (erythromycin and azithromycin) resistance marker genes mphA, ereB, and ermB were found in 28, 3 and 5% of bacterial isolates, respectively; while 26, 12, 17, 32, 7, 4 and 3% of the MDR bacterial isolates carried the extended spectrum β-lactamase (ESBL)-related genes e.g., bla(TEM), bla(SHV), bla(CMY-9), bla(CTX-M1), bla(CTX-M2), bla(CMY-2) and bla(OXA) respectively. Majority of the MDR gut bacteria harbored large plasmids [e.g., 140 MDa (43%), 105 MDa (30%), 90 MDa (14%)] carrying invasion and related antibiotic resistance marker genes. CONCLUSIONS: Our results suggest gut of young Bangladeshi children to be an important reservoir for multi-drug resistant pathogenic bacteria carrying ESBL related genes. | 2017 | 28439298 |
| 1168 | 7 | 0.9997 | Dairy Cattle and the Iconic Autochthonous Cattle in Northern Portugal Are Reservoirs of Multidrug-Resistant Escherichia coli. Background/Objectives: Animals destined for human consumption play a key role in potentially transmitting bacteria carrying antibiotic resistance genes. However, there is limited knowledge about the carriage of antibiotic-resistant bacteria in native breeds. We aimed to characterize the phenotypic profiles and antibiotic resistance genes in Escherichia coli isolated from bovines, including three native Portuguese bovine breeds. Methods: Forty-nine E. coli isolates were selected from 640 fecal samples pooled by age group (eight adult or eight calf samples) from each farm, representing both dairy cattle raised in intensive systems and meat cattle raised in extensive systems in Northern Portugal. The presumptive E. coli colonies plated onto MacConkey agar were confirmed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). The antibiotic resistance profiles were screened by antimicrobial susceptibility testing (EUCAST/CLSI guidelines), and the antibiotic resistance genes by PCR. Results: Most isolates showed resistance to ampicillin (69%), tetracycline (57%), gentamicin (55%), and trimethoprim + sulfamethoxazole (53%), with no resistance to imipenem. Resistance to at least one antibiotic was found in 92% of isolates, while 59% exhibited multidrug resistance. Most calf isolates, including those from native breeds, showed a multidrug-resistant phenotype. Among the adults, this was only observed in Holstein-Friesian and Barrosã cattle. None of the Holstein-Friesian isolates were susceptible to all the tested antibiotics. ESBL-producing E. coli was identified in 39% of isolates, including those from Holstein-Friesian calves and adults, Cachena calves and Minhota adults. The sul2 gene was detected in 69% of isolates, followed by bla(CTX-M) (45%), aac(3')-IV (41%), and aac(6')-Ib-cr (31%), with a higher prevalence in adults. Conclusions: This pioneering study highlights the concerning presence of multidrug-resistant E. coli in native Portuguese cattle breeds. | 2024 | 39766598 |
| 1155 | 8 | 0.9997 | Prevalence and antimicrobial resistance profiles of Escherichia coli isolated from free-range pigs. INTRODUCTION: Numerous studies about antimicrobial resistant Escherichia coli (E. coli) of animal origins have been conducted around the world, most of them focus on bacteria from animals raised in intensive breeding farms, but systematic studies on antimicrobial resistance in E. coli of free range animals are still lacking. METHODOLOGY: This study aimed to investigate the prevalence and antimicrobial resistance profiles of E. coli from free-range pigs in Laiwu mountainous areas, eastern China. RESULTS: Among 123 fecal samples, 123 non-duplicate E. coli were obtained with an isolation rate of 100.0% (123/123). These E. coli showed the highest resistance rate to tetracycline (77/123, 62.6%), but all were sensitive to amoxicillin/clavulanic acid. Thirty-eight E. coli (38/123, 30.9%) showed multidrug resistance (MDR). Among 123 E. coli isolates, only 39 carried antimicrobial resistant genes detected in this study. Of these 39 isolates, blaTEM-1, blaCTX-M-14, blaCTX-M-15, qnrB, qnrD, qnrS1, floR and cfr genes were detected in 13, 9, 4, 7, 10, 7, 20, and 7 isolates, respectively. blaTEM-1 and blaCTX-M-14 genes were concomitantly detected in 6 isolates, and blaTEM, qnrB, qnrS and qnrD genes were concomitantly detected in 7 isolates. CONCLUSIONS: Free-ranging pigs may be regarded as a potential reservoir for antibiotic resistant genes. | 2017 | 31085827 |
| 1315 | 9 | 0.9997 | Neonatal calf diarrhea: A potent reservoir of multi-drug resistant bacteria, environmental contamination and public health hazard in Pakistan. Though emergence of multi-drug resistant bacteria in the environment is a demonstrated worldwide phenomenon, limited research is reported about the prevalence of resistant bacteria in fecal ecology of neonatal calf diarrhea (NCD) animals in Pakistan. The present study aimed to identify and assess the prevalence of bacterial pathogens and their resistance potential in the fecal ecology of NCD diseased animals of Pakistan. The presence of antibiotic resistance genes (bla(TEM), bla(NDM-1), bla(CTX-M), qnrS) was also investigated. A total of 51 bacterial isolates were recovered from feces of young diarrheic animals (n = 11), collected from 7 cities of Pakistan and identified on the basis of 16S rRNA gene sequence and phylogenetic analysis. Selected isolates were subjected to antimicrobial susceptibility by disc diffusion method while polymerase chain reaction (PCR) was used to characterize the bla(TEM), bla(NDM-1), bla(CTX-M), qnrS and mcr-1 antibiotic resistance genes. Based on the 16S rRNA gene sequences (Accession numbers: LC488898 to LC488948), all isolates were identified that belonged to seventeen genera with the highest prevalence rate for phylum Proteobacteria and genus Bacillus (23%). Antibiotic susceptibility explained the prevalence of resistance in isolates ciprofloxacin (100%), ampicillin (100%), sulfamethoxazole-trimethoprim (85%), tetracycline (75%), amoxicillin (55%), ofloxacin (50%), ceftazidime (45%), amoxicillin/clavulanic acid (45%), levofloxacin (30%), cefpodoxime (25%), cefotaxime (25%), cefotaxime/clavulanic acid (20%), and imipenem (10%). MICs demonstrated that almost 90% isolates were multi-drug resistant (against at least three antibiotics), specially against ciprofloxacin, and tetracycline with the highest resistance levels for Shigella sp. (NCCP-421) (MIC-CIP up to 75 μg mL(-1)) and Escherichia sp. (NCCP-432) (MIC-TET up to 250 μg mL(-1)). PCR-assisted detection of antibiotic resistance genes showed that 54% isolates were positive for bla(TEM) gene, 7% isolates were positive for bla(CTX-M) gene, 23% isolates were positive for each of qnrS and mcr-1 genes, 23% isolates were co-positive in combinations of qnrS and mcr-1 genes and bla(TEM) and mcr-1 genes, whereas none of the isolate showed presence of bla(NDM-1) gene. | 2021 | 34426357 |
| 1304 | 10 | 0.9997 | Serovar and sequence type distribution and phenotypic and genotypic antimicrobial resistance of Salmonella originating from pet animals in Chongqing, China. A total of 334 Salmonella isolates were recovered from 6,223 pet rectal samples collected at 50 pet clinics, 42 pet shops, 7 residential areas, and 4 plazas. Forty serovars were identified that included all strains except for one isolate that did not cluster via self-agglutination, with Salmonella Typhimurium monophasic variant, Salmonella Kentucky, Salmonella Enteritidis, Salmonella Pomona, and Salmonella Give being the predominant serovars. Fifty-one sequence types were identified among the isolates, and ST198, ST11, ST19, ST451, ST34, and ST155 were the most common. The top four dominant antimicrobials to which isolates were resistant were sulfisoxazole, ampicillin, doxycycline, and tetracycline, and 217 isolates exhibited multidrug resistance. The prevalence of β-lactamase genes in Salmonella isolates was 59.6%, and among these isolates, 185 harbored bla(TEM), followed by bla(CTX-M) (66) and bla(OXA) (10). Moreover, six PMQR genes, namely, including qnrA (4.8%), qnrB (4.2%), qnrD (0.9%), qnrS (18.9%), aac(6')-Ib-cr (16.5%), and oqxB (1.5%), were detected. QRDR mutations (76.6%) were very common in Salmonella isolates, with the most frequent mutation in parC (T57S) (47.3%). Furthermore, we detected six tetracycline resistance genes in 176 isolates, namely, tet(A) (39.5%), tet(B) (8.1%), tet(M) (7.7%), tet(D) (5.4%), tet(J) (3.3%), and tet(C) (1.8%), and three sulfonamide resistance genes in 303 isolates, namely, sul1 (84.4%), sul2 (31.1%), and sul3 (4.2%). Finally, we found 86 isolates simultaneously harboring four types of resistance genes that cotransferred 2-7 resistance genes to recipient bacteria. The frequent occurrence of antimicrobial resistance, particularly in dogs and cats, suggests that antibiotic misuse may be driving multidrug-resistant Salmonella among pets.IMPORTANCEPet-associated human salmonellosis has been reported for many years, and antimicrobial resistance in pet-associated Salmonella has become a serious public health problem and has attracted increasing attention. There are no reports of Salmonella from pets and their antimicrobial resistance in Chongqing, China. In this study, we investigated the prevalence, serovar diversity, sequence types, and antimicrobial resistance of Salmonella strains isolated from pet fecal samples in Chongqing. In addition, β-lactamase, QRDR, PMQR, tetracycline and sulfonamide resistance genes, and mutations in QRDRs in Salmonella isolates were examined. Our findings demonstrated the diversity of serovars and sequence types of Salmonella isolates. The isolates were widely resistant to antimicrobials, notably with a high proportion of multidrug-resistant strains, which highlights the potential direct or indirect transmission of multidrug-resistant Salmonella from pets to humans. Furthermore, resistance genes were widely prevalent in the isolates, and most of the resistance genes were spread horizontally between strains. | 2024 | 38757951 |
| 1311 | 11 | 0.9997 | Prevalence and Molecular Characterization of Antimicrobial Resistance in Escherichia coli Isolated from Raw Milk and Raw Milk Cheese in Egypt. The goal of this study was to examine antimicrobial resistance and characterize the implicated genes in 222 isolates of Escherichia coli from 187 samples of raw milk and the two most popular cheeses in Egypt. E. coli isolates were tested for susceptibility to 12 antimicrobials by a disk diffusion method. Among the 222 E. coli isolates, 66 (29.7%) were resistant to one or more antimicrobials, and half of these resistant isolates showed a multidrug resistance phenotype (resistance to at least three different drug classes). The resistance traits were observed to tetracycline (27.5%), ampicillin (18.9%), streptomycin (18.5%), sulfamethoxazole-trimethoprim (11.3%), cefotaxime (4.5%), kanamycin (4.1%), ceftazidime (3.6%), chloramphenicol (2.3%), nalidixic acid (1.8%), and ciprofloxacin (1.4%). No resistance to fosfomycin and imipenem was observed. Tetracycline resistance genes tetA, tetB, and tetD were detected in 53 isolates, 9 isolates, and 1 isolate, respectively, but tetC was not detected. Aminoglycoside resistance genes strA, strB, aadA, and aphA1 were detected in 41, 41, 11, and 9 isolates, respectively. Sulfonamide resistance genes sul1, sul2, and sul3 were detected in 7, 25, and 3 isolates, respectively. Of 42 ampicillin-resistant isolates, bla(TEM), bla(CTX-M), and bla(SHV) were detected in 40, 9, and 3 isolates, respectively, and 10 (23.8%) ampicillin-resistant isolates were found to produce extended-spectrum β-lactamase. Each bla gene of extended-spectrum β-lactamase-producing E. coli was further subtyped to be bla(CTX-M-15), bla(CTX-M-104), bla(TEM-1), and bla(SHV-12). The class 1 integron was also detected in 28 resistant isolates, and three different patterns were obtained by PCR-restriction fragment length polymorphism. Sequencing analysis of the variable region revealed that four isolates had dfrA12/orfF/aadA2, two had aadA22, and one had dfrA1/aadA1. These data suggest that antimicrobial-resistant E. coli are widely distributed in the milk production and processing environment in Egypt and may play a role in dissemination of antimicrobial resistance to other pathogenic and commensal bacteria. | 2018 | 29323530 |
| 1151 | 12 | 0.9997 | Genomic Analysis of Third Generation Cephalosporin Resistant Escherichia coli from Dairy Cow Manure. The production of extended-spectrum β-lactamases (ESBLs) conferring resistance to new derivatives of β-lactams is a major public health threat if present in pathogenic Gram-negative bacteria. The objective of this study was to characterize ceftiofur (TIO)- or cefotaxime (FOX)-resistant Escherichia coli isolated from dairy cow manure. Twenty-four manure samples were collected from four farms and incubated under anaerobic conditions for 20 weeks at 4 °C or at 25 °C. A total of 37 TIO- or FOX-resistant E. coli were isolated from two of the four farms to determine their susceptibility to 14 antibiotics. Among the 37 resistant E. coli, 10 different serotypes were identified, with O8:H1 being the predominant serotype (n = 17). Five isolates belonged to each of serotypes O9:NM and O153:H42, respectively. All 37 cephalosporin resistant isolates were multi-resistant with the most prevalent resistance spectrum being amoxicillin-clavulanic acid-ampicillin-cefoxitin-ceftiofur-ceftriaxone-chloramphenicol-streptomycin-sulfisoxazole-tetracycline-trimethoprim-sulfamethoxazole. The genomes of 18 selected isolates were then sequenced and compared to 14 selected human pathogenic E. coli reference genomes obtained from public repositories using different bioinformatics approaches. As expected, all 18 sequenced isolates carried at least one β-lactamase bla gene: TEM-1, TEM-81, CTX-M115, CTX-M15, OXA-1, or CMY-2. Several other antibiotic resistance genes (ARGs) and virulence determinants were detected in the sequenced isolates and all of them harbored antimicrobial resistance plasmids belonging to classic Inc groups. Our results confirm the presence of diverse ESBL producing E. coli isolates in dairy cow manure stored for a short period of time. Such manure might constitute a reservoir of resistance and virulence genes for other bacteria that share the same environment. | 2017 | 29149094 |
| 2675 | 13 | 0.9997 | 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 |
| 2676 | 14 | 0.9997 | 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 |
| 1312 | 15 | 0.9997 | Antimicrobial resistance profiles among Escherichia coli strains isolated from commercial and cooked foods. A total of 4330 food samples of which microbiological standard for Escherichia coli is negative in Korea were determined for the frequency of E. coli. Ninety six samples (2.2%) were positive for E. coli. Detection rate of E. coli varied significantly by food type and ranged from 0.3% to 10.9%. Seasoned raw meat (yukhoe) and cold bean-soup had the highest prevalence for E. coli (10.9%) followed by gimbap (5.2%), meat broth for cold noodle (2.9%) and sprout (2.1%). E. coli isolates (n=96) were investigated for their phenotypic and genotypic antimicrobial resistance patterns. Seventeen E. coli isolates (17.7%) were resistant to one or more antimicrobial agents tested. High rates of resistance to the following drugs were observed: tetracycline (15.6%), streptomycin (12.5%), ampicillin (10.4%), nalidixic acid (9.4%) and ticarcillin (9.4%). All ampicillin resistant isolates were screened for extended-spectrum β-lactamase (ESBL) production by the combination disk test. None of the E. coli isolates produced ESBLs. Seventeen out of 96 E. coli isolates which were resistant to at least one antibiotic were investigated by PCR for the presence of 3 classes of antimicrobial resistance genes (tetracycline, aminoglycosides and beta-lactams). The tetracycline resistance genes tetA and tetB were found in 7 and 5 isolates, respectively. The aminoglycoside resistance genes, strA/B, aphA1, aadA and aac(3)-IV were found in 9, 5, 2 and 2 isolates, respectively. The beta-lactam resistance gene, bla(TEM) was found in 7 isolates. Results of this study show that 13 E. coli isolates were multidrug resistant (to three or more antibiotics) and 12 isolates carried at least one antimicrobial resistance gene. These isolates can act as the reservoir for antimicrobial resistance genes and facilitate the dissemination of these genes to other pathogenic and commensal bacteria. Adequate intervention to reduce microbial contamination of these foods is strongly recommended. | 2012 | 23107506 |
| 1200 | 16 | 0.9997 | Virulence and Antimicrobial Resistance Patterns of Salmonella spp. Recovered From Migratory and Captive Wild Birds. BACKGROUND: Salmonella spp., especially those are resistant to extended-spectrum β-lactamase (ESBL), are considered as major concern to global health due to their emergence and dissemination. AIM: The aim of this study was to investigate the virulence and antimicrobial resistance (AMR) profile of Salmonella spp. from migratory and captive wild birds. METHOD: A total 262 faecal samples were collected, and the identification of Salmonella spp. was carried out using a standard culture and PCR as well as molecular detection of virulence and AMR genes. RESULTS: The overall prevalence of Salmonella was determined to be 30.92% (95% CI = 25.63-36.75). Migratory birds exhibited highest prevalence (38.10%), whereas wild birds in captivity showed a lower prevalence (23.40%). The agfA gene was detected at a higher rate at 24.69%. Salmonella spp. exhibited 100% resistance to tetracycline, followed by 58% ampicillin and 46% streptomycin. In addition, there was a resistance rate to ceftriaxone of 17% and to colistin sulphate of 25%. Interestingly, levofloxacin alone displayed 100% sensitivity across all isolates, while ciprofloxacin and azithromycin showed 73% and 64% sensitivity, respectively. The MAR index was 0.25 and 0.42, and 74.07% of all isolates showed multidrug resistance (MDR). It was shown that migratory and captive wild birds contained ESBL genes blaTEM (94.34% and 49.06%) and blaSHV (13.33% and 10%), respectively. Genes responsible for sulphonamide (sul1) resistance were detected in 13.33% and 79% of wild and migratory birds, respectively. CONCLUSION: Salmonella has been found in captive wild and migratory birds and could act as reservoirs for the transmission of MDR and ESBL bacteria. | 2024 | 39494993 |
| 1157 | 17 | 0.9997 | Isolation and Molecular Characterization of Antimicrobial Resistant Escherichia coli from Healthy Broilers in Retail Chicken Outlets of Hotspot Cities in Southern India. E. coli is one of the first commensal bacteria to colonize the chicken gut. It may act as a source for the spread of antibiotic resistance to human via the food chain and contamination of the environment. Isolation and characterization of such E. coli from commercial broilers in retail outlets of Southern India were carried out. Eighty-three E. coli isolates (76.9%) were obtained from cloacal/meat swabs (108 samples). Phenotypically, 78.3% of isolates were ESBL producers, 69.9% were fluoroquinolone-resistant, and 6% were carbapenemase producers. Genotypically, the blaSHV, blaTEM, and blaCTX-M were present in 48.2%, 43.4%, and 10.8% of the isolates, respectively. These isolates also carried fluoroquinolone-resistant genes viz qnrB (31.3%) and qnrS (34.9%) but not carbapenemase genes. Overall, ESBL were identified in 72.3% of isolates and fluoroquinolone-resistance genes in 51.8%. Strikingly, 53% of the isolates were multidrug-resistant, with both ESBL and fluoroquinolone-resistant genes. The study revealed the presence of MDR E. coli strains in broiler meat at retail outlets indicating the potential public health risks. | 2025 | 40778947 |
| 1029 | 18 | 0.9997 | Phylogenetic relationships, virulence and antimicrobial resistance properties of Klebsiella sp. isolated from pet turtles in Korea. Klebsiella sp. are responsible for a multitude of infectious diseases in both humans and animals. In this study, phylogenetic relationships, virulence and antimicrobial resistance gene properties of 16 Klebsiella sp. isolated from 49 pet turtles were investigated. The isolates including Klebsiella oxytoca (n = 13) and Klebsiella pneumoniae (n = 3) were identified using 16S rRNA gene sequencing and each species formed distinct clusters in the neighbour-joining phylogenetic tree. The prevalence of virulence genes including ureC (100%) and kfu (68·75%) was observed among the isolates using Polymerase chain reaction (PCR) assay. The fimH, mrkD and rmpA genes were detected in all K. pneumoniae while these were absent in every K. oxytoca isolate. In antimicrobial susceptibility testing, high resistance rates were observed against ampicillin (100%) and cephalothin (62·50%). The resistance rates against imipenem, tetracycline, trimethoprim/sulfamethoxazole, nalidixic acid and ciprofloxacin were 12·50, 12·50, 12·50, 6·25 and 6·25% respectively. The presence of antimicrobial resistance genes such as plasmid-mediated quinolone resistance (PMQR) [qnrB (37·50%), qnrA (31·25%), qnrS (12·50%) and aac(6')-Ib-cr (12·50%)], extended-spectrum β-lactamase (ESBL) [bla(CTX-M) (18·75%)], β-lactamase [bla(SHV-1) (18·75%)] and tetracycline resistance [tetE (12·50%)] was observed. The results revealed that pet turtle-borne Klebsiella sp. may carry different types of virulence and antimicrobial resistance genes which represents a potential threat to public health. SIGNIFICANCE AND IMPACT OF THE STUDY: Klebsiella sp. are nonmotile Gram-negative bacteria that are found in different environments. The virulence and antimicrobial resistance properties of pet turtle-borne Klebsiella sp. have not been studied before. Phylogenetic relationships, virulence traits and antimicrobial resistance profiles of pet turtle-borne Klebsiella sp. were characterized for the first time in Korea. Multiple virulence and antimicrobial resistance genes were observed among the isolates. The occurrence of virulence and antimicrobial resistance determinants in Klebsiella sp. may represent a potential threat to public health. | 2020 | 31671218 |
| 1149 | 19 | 0.9997 | Antimicrobial resistance, Extended-Spectrum β-Lactamase production and virulence genes in Salmonella enterica and Escherichia coli isolates from estuarine environment. The impact of antimicrobial resistance (AMR) on global public health has been widely documented. AMR in the environment poses a serious threat to both human and animal health but is frequently overlooked. This study aimed to characterize the association between phenotype and genotype of AMR, virulence genes and Extended-Spectrum β-Lactamase (ESBL) production from estuarine environment. The Salmonella (n = 126) and E. coli (n = 409) were isolated from oysters and estuarine water in Thailand. The isolates of Salmonella (96.9%) and E. coli (91.4%) showed resistance to at least one antimicrobial agent. Multidrug resistance (MDR) was 40.1% of Salmonella and 23.0% of E. coli. Resistance to sulfamethoxazole was most common in Salmonella (95.2%) and E. coli (77.8%). The common resistance genes found in Salmonella were sul3 (14.3%), followed by blaTEM (11.9%), and cmlA (11.9%), while most E. coli were blaTEM (31.5%) and tetA (25.4%). The ESBL production was detected in Salmonella (1.6%, n = 2) of which one isolate was positive to blaTEM-1. Eight E. coli isolates (2.0%) were ESBL producers, of which three isolates carried blaCTX-M-55 and one isolate was blaTEM-1. Predominant virulence genes identified in Salmonella were invA (77.0%), stn (77.0%), and fimA (69.0%), while those in E. coli isolates were stx1 (17.8%), lt (11.7%), and stx2 (1.2%). Logistic regression models showed the statistical association between resistance phenotype, virulence genes and ESBL production (p < 0.05). The findings highlighted that estuarine environment were potential hotspots of resistance. One Health should be implemented to prevent AMR bacteria spreading. | 2023 | 37115770 |