# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 2969 | 0 | 1.0000 | Colistin-Resistant Escherichia coli Isolated from Houseflies and Feces of Cattle and Pigs at a Slaughterhouse in Lima, Peru. Background: Pigs and cattle have been implicated as reservoirs of antimicrobial resistance genes (ARGs) that can spread to humans, and houseflies are considered potential carriers of bacteria with ARGs that could contribute to their spread to the environment, including food, animals, and humans. Methods: In this study, 107, 145, and 127 Escherichia coli strains were isolated from houseflies, pigs, and cattle, respectively, from a slaughterhouse in Lima, Peru. Antimicrobial susceptibility testing was performed using the Kirby-Bauer method, where thirteen antibiotics were used. Strains were also plated on CHROMagar COL-APSE agar, and colistin's minimum inhibitory concentration (MIC) was determined. Colistin-resistant E. coli strains were subjected to whole genome sequencing. Results: 7.8% (8/107), 1.38% (2/145), and 0.79% (1/127) of E. coli strains isolated from houseflies, pigs, and cattle, respectively, were resistant to colistin (MIC ≥ 4 µg/mL). ARGs associated with resistance to more than 6 different antibiotic classes were identified, including tetracyclines, beta-lactams, fluoroquinolones, nitroimidazoles, trimethoprim and amphenicols. Conclusions: This study suggests that flies could contribute to the dissemination of ARG carrying bacteria and shows the potential risk of animals and meat production systems as reservoirs of ARG carrying bacteria. | 2025 | 40868012 |
| 1145 | 1 | 0.9999 | Abundance of Mobilized Colistin Resistance Gene (mcr-1) in Commensal Escherichia coli from Diverse Sources. Aims: Antimicrobial resistance (AMR) spreads not only by pathogenic but also by commensal bacteria, and the latter can become a reservoir for resistance genes. This study was aimed to investigate the AMR patterns along with the presence of mobilized colistin resistance (mcr) genes in commensal Escherichia coli circulating in chickens, farm environments, street foods, and human patients. Materials and Methods: By a cross-sectional survey, isolates obtained from 530 samples were tested for their AMR profiles against 9 antimicrobials. Minimum inhibitory concentration (MIC) of the phenotypically colistin-resistant isolates was determined and screened for a set of mcr genes followed by sequencing of mcr-1 gene in the multidrug-resistant (MDR) isolates. Results: A total of 313 E. coli strains were isolated and confirmed by polymerase chain reaction. Antimicrobial susceptibility testing revealed that about 98% (confidence interval [95% CI] 95-99) of the isolates were MDR, and 58% (95% CI 52-63) isolates exhibited resistance to colistin. MIC values of colistin against the isolates ranged from 4 to 64 mg/L. Except for human patients, 20.4% colistin-resistant isolates from other sources of isolation had mcr-1 gene. Conclusions: There is abundance of commensal MDR E. coli strains with the acquisition of mcr-1 gene circulating in chickens and farm environments in Bangladesh. | 2021 | 33909471 |
| 1622 | 2 | 0.9999 | Antimicrobial Susceptibility and Frequency of bla and qnr Genes in Salmonella enterica Isolated from Slaughtered Pigs. Salmonella enterica is known as one of the most common foodborne pathogens worldwide. While salmonellosis is usually self-limiting, severe infections may require antimicrobial therapy. However, increasing resistance of Salmonella to antimicrobials, particularly fluoroquinolones and cephalosporins, is of utmost concern. The present study aimed to investigate the antimicrobial susceptibility of S. enterica isolated from pork, the major product in Philippine livestock production. Our results show that both the qnrS and the bla(TEM) antimicrobial resistance genes were present in 61.2% of the isolates. While qnrA (12.9%) and qnrB (39.3%) were found less frequently, co-carriage of bla(TEM) and one to three qnr subtypes was observed in 45.5% of the isolates. Co-carriage of bla(TEM) and bla(CTX-M) was also observed in 3.9% of the isolates. Antimicrobial susceptibility testing revealed that the majority of isolates were non-susceptible to ampicillin and trimethoprim/sulfamethoxazole, and 13.5% of the isolates were multidrug-resistant (MDR). MDR isolates belonged to either O:3,10, O:4, or an unidentified serogroup. High numbers of S. enterica carrying antimicrobial resistance genes (ARG), specifically the presence of isolates co-carrying resistance to both β-lactams and fluoroquinolones, raise a concern on antimicrobial use in the Philippine hog industry and on possible transmission of ARG to other bacteria. | 2021 | 34943653 |
| 1613 | 3 | 0.9999 | Research note: Occurrence of mcr-encoded colistin resistance in Escherichia coli from pigs and pig farm workers in Vietnam. WHO considers colistin as a highest priority critically important drug for human health, and occurrence of colistin-resistant bacteria in livestock is of health concern. The current study determined occurrence of colistin-resistant Escherichia coli in pigs and workers at pig farms in Vietnam, and investigated the genetic background for resistance. Colistin-resistant E. coli were detected from pigs in 53/116 (45.7%) farms, and from workers taking care of the pigs in 21/94 (22.3%) farms. Colistin-resistant isolates showed MIC to colistin between 4-16 mg/L, they were multidrug resistant (99%) and resistance was caused by the presence of mcr-1 genes in 97/102 (95.1%) E. coli from pigs and in 31/34 (91.1%) isolates from humans. mcr-1 is considered a plasmid-encoded gene, but this was not confirmed in the current investigation. In total, one pig isolate carried both mcr-1 and mcr-3 genes, whereas mcr-2, mcr-4 and mcr-5 genes were not detected. Shared resistance profiles between pig and human isolates on the same farm was only observed in four farms. The study showed that commensal E. coli from pigs in Vietnam constitute a reservoir for colistin-resitant E. coli, however, further studies are needed to confirm that mcr genes are associated with plasmids and their importance for human health. | 2020 | 37333956 |
| 2949 | 4 | 0.9999 | Genomic analysis of multidrug-resistant Escherichia coli strains carrying the mcr-1 gene recovered from pigs in Lima-Peru. Antibiotic resistance is a current problem that significantly impacts overall health. The dissemination of antibiotic resistance genes (ARGs) to urban areas primarily occurs through ARG-carrying bacteria present in the gut microbiota of animals raised in intensive farming settings, such as pig production. Hence, this study aimed to isolate and analyzed 87 Escherichia coli strains from pig fecal samples obtained from intensive farms in Lima Department. The isolates were subjected to Kirby-Bauer-Disk Diffusion Test and PCR for mcr-1 gene identification. Disk-diffusion assay revealed a high level of resistance among these isolates to oxytetracycline, ampicillin, cephalothin, chloramphenicol, ciprofloxacin, and doxycycline. PCR analysis identified the mcr-1 gene in 8% (7/87) E. coli isolates. Further, whole genome sequencing was conducted on 17 isolates, including multidrug resistance (MDR) E. coli and/or mcr-1 gene carriers. This analysis unveiled a diverse array of ARGs. Alongside the mcr-1 gene, the bla(CTX-M55) gene was particularly noteworthy as it confers resistance to third generation cephalosporins, including ceftriaxone. MDR E. coli genomes exhibited other ARGs encoding resistance to fosfomycin (fosA3), quinolones (qnrB19, qnrS1, qnrE1), tetracyclines (tetA, tetB, tetD, tetM), sulfonamides (sul1, sul2, sul3), amphenicols (cmlA1, floR), lincosamides (inuE), as well as various aminoglycoside resistance genes. Additionally, Multi Locus Sequence Typing (MLST) revealed a high diversity of E. coli strains, including ST10, a pandemic clone. This information provides evidence of the dissemination of highly significant ARGs in public health. Therefore, it is imperative to implement measures aimed at mitigating and preventing the transmission of MDR bacteria carrying ARGs to urban environments. | 2023 | 37473695 |
| 1620 | 5 | 0.9999 | A survey of antimicrobial-resistant Escherichia coli prevalence in wild mammals in Japan using antimicrobial-containing media. The emergence and spread of antimicrobial-resistant bacteria and resistance genes pose serious human and animal health concerns. Therefore, to control antimicrobial-resistant bacteria in the environment, the status of antimicrobial resistance of Escherichia coli in a variety of wild mammals and their prevalence were examined using antimicrobial-containing media. In total, 750 isolates were obtained from 274/366 (74.9%) wild mammals, and antimicrobial-resistant E. coli was detected in 37/750 isolates (4.9%) from 7 animal species (26/366 [7.1%] individuals). Using antimicrobial-containing media, 14 cefotaxime (CTX)- and 35 nalidixic acid-resistant isolates were obtained from 5 (1.4%) and 17 (4.6%) individuals, respectively. CTX-resistant isolates carried bla(CTX-M-27), bla(CTX-M-55), bla(CTX-M-1), and bla(CMY-2), with multiple resistance genes. Fluoroquinolone-resistant isolates had multiple mutations in the quinolone-resistance determining regions of gyrA and parC or qnrB19. Most resistant isolates exhibited resistance to multiple antimicrobials. The prevalence of antimicrobial-resistant bacteria observed in wild mammals was low; however, it is essential to elucidate the causative factors related to the low prevalence and transmission route of antimicrobial-resistant bacteria/resistance genes released from human activities to wild animals and prevent an increase in their frequency. | 2022 | 36310042 |
| 1153 | 6 | 0.9999 | Antimicrobial resistance, virulence factors and genetic diversity of Escherichia coli isolates from household water supply in Dhaka, Bangladesh. BACKGROUND: Unsafe water supplies continue to raise public health concerns, especially in urban areas in low resource countries. To understand the extent of public health risk attributed to supply water in Dhaka city, Bangladesh, Escherichia coli isolated from tap water samples collected from different locations of the city were characterized for their antibiotic resistance, pathogenic properties and genetic diversity. METHODOLOGY/PRINCIPAL FINDINGS: A total of 233 E. coli isolates obtained from 175 tap water samples were analysed for susceptibility to 16 different antibiotics and for the presence of genes associated with virulence and antibiotic resistance. Nearly 36% (n = 84) of the isolates were multi-drug(≥ 3 classes of antibiotics) resistant (MDR) and 26% (n = 22) of these were positive for extended spectrum β-lactamase (ESBL). Of the 22 ESBL-producers, 20 were positive for bla CTX-M-15, 7 for bla OXA-1-group (all had bla OXA-47) and 2 for bla CMY-2. Quinolone resistance genes, qnrS and qnrB were detected in 6 and 2 isolates, respectively. Around 7% (n = 16) of the isolates carried virulence gene(s) characteristic of pathogenic E. coli; 11 of these contained lt and/or st and thus belonged to enterotoxigenic E. coli and 5 contained bfp and eae and thus belonged to enteropathogenic E. coli. All MDR isolates carried multiple plasmids (2 to 8) of varying sizes ranging from 1.2 to >120 MDa. Ampicillin and ceftriaxone resistance were co-transferred in conjugative plasmids of 70 to 100 MDa in size, while ampicillin, trimethoprim-sulfamethoxazole and tetracycline resistance were co-transferred in conjugative plasmids of 50 to 90 MDa. Pulsed-field gel electrophoresis analysis revealed diverse genetic fingerprints of pathogenic isolates. SIGNIFICANCE: Multi-drug resistant E. coli are wide spread in public water supply in Dhaka city, Bangladesh. Transmission of resistant bacteria and plasmids through supply water pose serious threats to public health in urban areas. | 2013 | 23573295 |
| 1152 | 7 | 0.9999 | 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 |
| 1143 | 8 | 0.9999 | Antimicrobial Resistance and Virulence Profiles of mcr-1-Positive Escherichia coli Isolated from Swine Farms in Heilongjiang Province of China. ABSTRACT: The emergence and global distribution of the mcr-1 gene for colistin resistance have become a public concern because of threats to the role of colistin as the last line of defense against some bacteria. Because of the prevalence of mcr-1-positive Escherichia coli isolates in food animals, production of these animals has been regarded as one of the major sources of amplification and spread of mcr-1. In this study, 249 E. coli isolates were recovered from 300 fecal samples collected from swine farms in Heilongjiang Province, People's Republic of China. Susceptibility testing revealed that 186 (74.70%) of these isolates were colistin resistant, and 86 were positive for mcr-1. The mcr-1-positive isolates had extensive antimicrobial resistance profiles and additional resistance genes, including blaTEM, blaCTX-M, aac3-IV, tet(A), floR, sul1, sul2, sul3, and oqxAB. No mutations in genes pmrAB and mgrB were associated with colistin resistance. Phylogenetic group analysis revealed that the mcr-1-positive E. coli isolates belonged to groups A (52.33% of isolates), B1 (33.72%), B2 (5.81%), and D (8.14%). The prevalence of the virulence-associated genes iutA, iroN, fimH, vat, ompA, and traT was moderate. Seven mcr-1-positive isolates were identified as extraintestinal pathogenic. Among 20 mcr-1-positive E. coli isolates, multilocus sequence typing revealed that sequence type 10 was the most common (five isolates). The conjugation assays revealed that the majority of mcr-1 genes were transferable at frequencies of 7.05 × 10-7 to 7.57 × 10-4. The results of this study indicate the need for monitoring and minimizing the further dissemination of mcr-1 among E. coli isolates in food animals, particularly swine. | 2020 | 32730609 |
| 1013 | 9 | 0.9999 | Molecular detection and antimicrobial resistance profiles of Extended-Spectrum Beta-Lactamase (ESBL) producing Escherichia coli in broiler chicken farms in Malaysia. Antimicrobial resistance is one of the major public health threats globally. This challenge has been aggravated with the overuse and misuse of antibiotics in food animals and humans. The present study aimed to investigate the prevalence of Extended-Spectrum β-lactamase (ESBL) genes in Escherichia coli (E. coli) isolated from broiler chickens in Kelantan, Malaysia. A total of 320 cloacal swabs were collected from farms in different districts of Kelantan and were analyzed using routine bacteriology, antimicrobial susceptibility test, and molecular techniques for further identification and characterization of ESBL encoding genes. Based on PCR detection for the E. coli species-specific Pho gene, 30.3% (97/320) of isolates were confirmed as E. coli, and 84.5% (82/97) of the isolates were positive for at least one ESBL gene. Majority of the isolates, 62.9% (61/97) were harboring blaCTX-M followed by 45.4% (44/97) of blaTEM genes, while 16.5% (16/97) of the isolates were positive for both mcr-1 and ESBL genes. Overall, 93.8% (90/97) of the E. coli were resistant to three or more antimicrobials; indicating that the isolates were multi-drug resistance. 90.7% of multiple antibiotic resistance (MAR) index value greater than 0.2, would also suggest the isolates were from high-risk sources of contamination. The MLST result shows that the isolates are widely diverse. Our findings provide insight into the alarmingly high distribution of antimicrobial resistant bacteria, mainly ESBL producing E. coli in apparently healthy chickens indicating the role of food animals in the emergence and spread of antimicrobial resistance, and the potential public health threats it may pose. | 2023 | 37205716 |
| 2966 | 10 | 0.9999 | Determination of antibiotic resistance patterns and genotypes of Escherichia coli isolated from wild birds. BACKGROUND: Curbing the potential negative impact of antibiotic resistance, one of our era's growing global public health crises, requires regular monitoring of the resistance situations, including the reservoir of resistance genes. Wild birds, a possible bioindicator of antibiotic resistance, have been suggested to play a role in the dissemination of antibiotic-resistant bacteria. Therefore, this study was conducted with the objective of determining the phenotypic and genotypic antibiotic resistance profiles of 100 Escherichia coli isolates of gull and pigeon origin by using the Kirby-Bauer disk diffusion method and PCR. Furthermore, the genetic relationships of the isolates were determined by RAPD-PCR. RESULTS: Phenotypic antibiotic susceptibility testing revealed that 63% (63/100) and 29% (29/100) of E. coli isolates were resistant to at least one antibiotic and multidrug-resistant (MDR), respectively. With the exception of cephalothin, to which the E. coli isolates were 100% susceptible, tetracycline (52%), kanamycin (38%), streptomycin (37%), ampicillin (28%), chloramphenicol (21%), trimethoprim/sulfamethoxazole (19%), gentamicin (13%), enrofloxacin (12%) and ciprofloxacin (12%) resistances were detected at varying degrees. Among the investigated resistance genes, tet(B) (66%), tet(A) (63%), aphA1 (48%), sul3 (34%), sul2 (26%), strA/strB (24%) and sul1 (16%) were detected. Regarding the genetic diversity of the isolates, the RAPD-PCR-based dendrograms divided both pigeon and gull isolates into five different clusters based on a 70% similarity threshold. Dendrogram analysis revealed 47-100% similarities among pigeon-origin strains and 40-100% similarities among gull-origin E.coli strains. CONCLUSIONS: This study revealed that gulls and pigeons carry MDR E. coli isolates, which may pose a risk to animal and human health by contaminating the environment with their feces. However, a large-scale epidemiological study investigating the genetic relationship of the strains from a "one health" point of view is warranted to determine the possible transmission patterns of antibiotic-resistant bacteria between wild birds, the environment, humans, and other hosts. Video Abstract. | 2024 | 38191447 |
| 2981 | 11 | 0.9999 | Investigation of plasmid-mediated resistance in E. coli isolated from healthy and diarrheic sheep and goats. Escherichia coli is zoonotic bacteria and the emergence of antimicrobial-resistant strains becomes a critical issue in both human and animal health globally. This study was therefore aimed to investigate the plasmid-mediated resistance in E. coli strains isolated from healthy and diarrheic sheep and goats. A total of 234 fecal samples were obtained from 157 sheep (99 healthy and 58 diarrheic) and 77 goats (32 healthy and 45 diarrheic) for the isolation and identification of E. coli. Plasmid DNA was extracted using the alkaline lysis method. Phenotypic antibiotic susceptibility profiles were determined against the three classes of antimicrobials, which resistance is mediated by plasmids (Cephalosporins, Fluoroquinolone, and Aminoglycosides) using the disc-diffusion method. The frequency of plasmid-mediated resistance genes was investigated by PCR. A total of 159 E. coli strains harbored plasmids. The isolates antibiogram showed different patterns of resistance in both healthy and diarrheic animals. A total of (82; 51.5%) E. coli strains were multidrug-resistant. rmtB gene was detected in all Aminoglycoside-resistant E. coli, and the ESBL-producing E. coli possessed different CTX-M genes. Similarly, fluoroquinolone-resistant E. coli possessed different qnr genes. On the analysis of the gyrB gene sequence of fluoroquinolone-resistant E. coli, multiple point mutations were revealed. In conclusion, a high prevalence of E. coli with high resistance patterns to antimicrobials was revealed in the current study, in addition to a wide distribution of their resistance determinants. These findings highlight the importance of sheep and goats as reservoirs for the dissemination of MDR E. coli and resistance gene horizontal transfer. | 2020 | 32127753 |
| 2967 | 12 | 0.9999 | Antibiotic susceptibility and prevalence of foodborne pathogens in poultry meat in Romania. INTRODUCTION: The occurrence of pathogenic strains in poultry meat is of growing concern in Romania. Another problem found on a global level is the continuous increase of antimicrobial resistance in bacteria isolated from food. This study aimed to evaluate the prevalence of pathogenic bacteria in poultry carcasses obtained in Romania in 2012-2013 and to reveal the most prevalent patterns of antimicrobial resistance in the isolated strains. METHODOLOGY: A total of 144 broiler chicken carcasses were evaluated according to classical microbiological methods. The DNA was extracted from the bacterial colonies and the resistance genes were identified by PCR. RESULTS: In 2012, 47.2% of the samples revealed at least one of the following bacteria: Campylobacter jejuni (9.72%; n = 7), Salmonella enterica serotype Enteritidis (4.17%; n = 3), Listeria monocytogenes (15.28%; n = 11), and Escherichia coli (16.67%; n = 12). In 2013, the number of positive samples of pathogenic bacteria decreased, although Campylobacter jejuni was isolated in a higher percentage (20.8% vs. 9.72%). The percentage of multidrug-resistant (MDR) bacteria was high (23%); the most prevalent pattern included resistance to tetracycline, sulfonamides, and quinolones/fluoroquinolones. All the resistant Salmonella and E. coli strains were tested for the presence of characteristic resistance genes (Kn, bla(TEM), tetA, tetB, tetG, DfrIa, aadA1a, Sul) and revealed that these isolates represent an important reservoir in the spread of this phenomenon. CONCLUSIONS: Our findings suggest that Romania urgently needs an integrated surveillance system within the entire chain, for drug-resistant pathogens isolated from poultry meat. | 2015 | 25596569 |
| 2972 | 13 | 0.9999 | Genetic characterisation of class 1 integrons among multidrug-resistant Salmonella serotypes in broiler chicken farms. OBJECTIVES: Antimicrobial resistance in Salmonella serotypes has been reported. Integrons play an important role in the dissemination of antimicrobial resistance genes in bacteria. Scarce literature is available on the identification of integrons in Salmonella isolated from broiler chickens. In this study, antimicrobial susceptibility testing and characterisation of class 1 integrons among multidrug-resistant (MDR) Salmonella enterica serotypes in broiler chicken farms in Egypt were performed. METHODS: Antimicrobial susceptibility was determined by the disk diffusion method. PCR was performed to detect antimicrobial resistance genes and class 1 integrons in the tested Salmonella serotypes. Gene sequencing of the variable region of a class 1 integron was performed. RESULTS: Salmonella spp. were detected in 26 (13.5%) of 192 broiler samples, with Salmonella Enteritidis being the most frequently detected serotype, followed by Salmonella Kentucky and Salmonella Typhimurium and other serotypes. A very high resistance rate was observed to trimethoprim/sulfamethoxazole (100%), whilst a low resistance rate was observed to cefuroxime (57.7%). MDR S. enterica isolates displayed resistance to ciprofloxacin and azithromycin. Class 1 integrons were detected in 20 (76.9%) of the 26 Salmonella isolates. A high prevalence of class 1 integrons, as the first recorded percentage in the literature, associated with MDR Salmonella isolates was observed. CONCLUSIONS: Antimicrobial resistance rates in Salmonella serotypes from broiler chicken farms were alarming, especially for ciprofloxacin and azithromycin. Thus, another therapeutic strategy other than antimicrobials is recommended to prevent outbreaks of MDR Salmonella. | 2018 | 29684574 |
| 1146 | 14 | 0.9999 | Molecular detection and prevalence of colistin-resistant Escherichia coli in poultry and humans: a one health perspective. Multidrug-resistant (MDR) bacteria significantly threaten humans and animals worldwide. Colistin is the last resort of antibiotics against gram-negative bacterial infections. Its irrational use in poultry is a major factor in transmitting MDR bacteria to humans. The present study investigated the risk factors, prevalence, and molecular detection of colistin resistance associated with poultry and humans. A total of (n = 140) cloacal swabs from chickens and human stool samples (n = 140) were processed to identify E. coli using conventional methods, followed by genotypic confirmation. Phenotypic and genotypic confirmation of antibiotic resistance genes qnrA, blaTEM, tetA, aadA, and mcr genes was performed on these E. coli isolates. These isolates were confirmed at 69.3% and 62.8% in chickens and humans, respectively. Limited education and poor hygiene significantly increased the infection rate (p = 0.0001). The E. coli isolates from commercial poultry showed 100% resistance to amoxicillin/clavulanic acid, 98.9% to ampicillin, and 93.8% to tetracycline. The E. coli isolates from humans exhibited 90% resistance to ciprofloxacin, 88% to ampicillin, and 85% to ceftriaxone. Among these, MDR E. coli isolates of both commercial poultry and humans, colistin resistance was found in 78.6% and 48.1%, respectively. Genotypic confirmation of mcr genes such as mcr-1 (42%), mcr-2 (19.6%), mcr-3 (15.1%), mcr-4 (7.6%), and mcr-5 (4.5%) in commercial poultry. However, only the mcr-1 (15.6%) gene was found in human isolates. The current study findings highlight the prevalence of mcr genes in E. coli, potentially contributing to broader antibiotic resistance concerns. | 2025 | 40956559 |
| 2970 | 15 | 0.9999 | Plasmid-mediated quinolone resistance in Escherichia coli isolates from commercial broiler chickens in Semnan, Iran. BACKGROUND AND OBJECTIVES: Antibiotic resistance within the poultry sector presents a considerable health concern due to treatment inefficacy and resistance transmission to humans and the environment. The investigation of plasmid-mediated quinolone resistance (PMQR) in Escherichia coli, acknowledged for its role in advancing resistance, remains inadequately studied in Iranian poultry. This study aimed to evaluate PMQR gene prevalence as well as to determine correlation between resistance phenotype and genotype in E. coli obtained from poultry colibacillosis. MATERIALS AND METHODS: A collection of 100 E. coli isolates from the viscera of broilers suspected to colibacillosis was assessed. Using the Kirby-Bauer disk diffusion method, antimicrobial susceptibility tests were conducted for ofloxacin, nalidixic acid, levofloxacin, ciprofloxacin, and ampicillin. Additionally, PCR was employed to screen for qnrS, qnrB, and aac(6)Ib-cr genes. RESULTS: Among the analyzed E. coli isolates, 51% demonstrated resistance to at least one of the tested antibiotics, with 17% exhibiting resistance to four different antibiotics. Nalidixic acid displayed the highest resistance rate at 48%, while ampicillin had the lowest at 16%. PMQR genes were detected in 28% of the E. coli isolates, with aac(6')-Ib-cr being the most prevalent at 14%, followed by qnrB in 13%, and qnrS in 7%. CONCLUSION: The study underscores the vital need for careful antibiotic usage in poultry to curb the emergence of antibiotic-resistant bacteria. The results illuminate the prevalence of PMQR genes and their association with resistance trends in Iranian poultry, forming a pivotal basis for forthcoming approaches to combat antibiotic resistance within the poultry sector. | 2024 | 38854977 |
| 1614 | 16 | 0.9999 | Dissemination of Multidrug-Resistant Commensal Escherichia coli in Feedlot Lambs in Southeastern Brazil. Antimicrobial resistance (AR) is a public health issue since it limits the choices to treat infections by Escherichia coli in humans and animals. In Brazil, the ovine meat market has grown in recent years, but studies about AR in sheep are still scarce. Thus, this study aims to investigate the presence of AR in E. coli isolated from lambs during feedlot. To this end, feces from 112 lambs with 2 months of age, after weaning, were collected on the first day of the animals in the feedlot (day 0), and on the last day before slaughtering (day 42). Isolates were selected in MacConkey agar supplemented with 4 mg/L of ceftiofur and identified by biochemical methods. Isolates were submitted to an antimicrobial susceptibility test by disc-diffusion and PCR to investigate genes for phylogenetic group, virulence determinants and resistance to the several antimicrobial classes tested. The genetic localization of the bla genes detected was elucidated by S1-PFGE followed by Southern blot-hybridizations. The isolates were typed by XbaI-PFGE and MLST methods. Seventy-eight E. coli were isolated from 8/112 (7.1%) animals on day 0, and from 55/112 (49.1%) animals on day 42. Since only fimH was present in almost all E. coli (97.4%) as a virulence gene, and also 88.5% belonged to phylogroups B1 or A, we consider that isolates represent intestinal commensal bacteria. The dendrogram separated the 78 non-virulent isolates in seven clusters, two of which comprised 50 E. coli belonging to ST/CC 1727/446 or ST 3994 recovered on day 42 commonly harboring the genotype bla (CMY -2)-aac(3)-IIa -tetA-sul1-sul2-floR-cmlA. Special attention should be given to the presence of bla (CTX-M-15), a worldwide gene spread, and bla (CTX-M-14), a hitherto undetected gene in Enterobacteriaceae from food-producing animals in Brazil. Importantly, E. coli lineages and plasmids carrying bla genes detected here have already been reported as sources of infection in humans either from animals, food, or the environment, which raises public health concerns. Hence, two types of commensal E. coli carrying important AR genes clearly prevailed during feedlot, but lambs are also reservoirs of bacteria carrying important AR genes such as bla (CTX-M-14) and bla (CTX-M-15), mostly related to antimicrobial treatment failure. | 2019 | 31293542 |
| 2932 | 17 | 0.9999 | Resistance to Sulfonamides and Dissemination of sul Genes Among Salmonella spp. Isolated from Food in Poland. Antimicrobial resistance of pathogenic bacteria, including Salmonella spp., is an emerging problem of food safety. Antimicrobial use can result in selection of resistant organisms. The food chain is considered a route of transmission of resistant pathogens to humans. In many European countries, sulfonamides are one of the most commonly used antimicrobials. The aim of our investigation was to assess the prevalence of sul genes and plasmid occurrence among sulfonamide-resistant Salmonella spp. Eighty-four sulfonamide-resistant isolates were collected in 2008 and 2013 from retail products in Poland. Minimal inhibitory concentration of all of these isolates was ≥1024 μg/mL. Resistant isolates were tested for the presence of sul1, sul2, sul3, and int1 genes by using multiplex polymerase chain reaction. In total, 44.0% (37/84) isolates carried the sul1 gene, 46.4% (39/84) were sul2 positive, while the sul3 gene was not detected in any of the sulfonamide-resistant isolates tested. It was found that 3.6% (3/84) of resistant Salmonella spp. contained sul1, sul2, and intI genes. All 33 intI-positive isolates carried the sul1 gene. Eleven of the sulfonamide-resistant isolates were negative for all the sul genes. Most of the sulfonamide-resistant Salmonella spp. harbored plasmids; only in eight isolates were no plasmids detected. Generally, the size of the plasmids ranged from approximately 2 kb to ≥90 kb. Our results revealed a relatively a high prevalence of sulfonamides-resistant Salmonella spp. isolated from retail food. Additionally, we have detected a high dissemination of plasmids and class 1 integrons that may enhance the spread of resistance genes in the food chain. | 2015 | 25785781 |
| 2611 | 18 | 0.9999 | Prevalence of antimicrobial-resistant bacteria in conventional vs. organic livestock farms in Egypt: a cross-sectional comparative study. The silent pandemic of antimicrobial resistance (AR) has been on the rise for the past decades. It is essential to determine the burden of AR in animal farms that spreads leading to human exposure. A total of 100 samples including soil, litter, animal excreta, and wastewater were collected from seven conventional and one organic farm in Egypt. The prevalence of extended-spectrum β-lactamase-producing Escherichia coli (ESBL-producing E. coli), fluoroquinolone-resistant E. coli, fluoroquinolone-resistant Salmonella, and vancomycin-resistant enterococci (VRE) was determined in studied farms. Conventional farms had a higher prevalence of antimicrobial-resistant bacteria than the organic farm (73.81% vs. 18.75%, P < .001). In conventional farms 21.43% of samples yielded mixed isolates; however, in the organic farm, only single isolates of ESBL-producing E. coli were detected. The most prevalent ESBL-production gene was blaTEM (82.14%), followed by blaCTX-M (48.22%), and blaSHV (19.64%), either alone or in combination with another gene. The most prevalent fluoroquinolone-resistance genes were qnrS (82.69%) and qnrB (42.30%), either alone or in combination with another gene(s). A total of five VRE isolates harbored vanA gene (83.33%), none carried vanB gene, and one isolate was negative for both genes. The studied conventional livestock farms had significantly higher rates of serious AR threats than the organic farm. | 2023 | 36688777 |
| 1012 | 19 | 0.9999 | Antimicrobial resistance profile and prevalence of extended-spectrum beta-lactamases (ESBL), AmpC beta-lactamases and colistin resistance (mcr) genes in Escherichia coli from swine between 1999 and 2018. The frequent usage of antibiotics in livestock has led to the spread of resistant bacteria within animals and their products, with a global warning in public health and veterinarians to monitor such resistances. This study aimed to determine antibiotic resistance patterns and genes in pig farms from Spain during the last twenty years. Susceptibility to six antibiotics commonly used in pig production was tested by qualitative (disk diffusion) and quantitative (minimum inhibitory concentration, MIC) methods in 200 strains of Escherichia coli which had been isolated between 1999 and 2018 from clinical cases of diarrhoea in neonatal and post-weaned piglets. Results showed resistance around 100% for amoxicillin and tetracycline since 1999, and a progressive increase in ceftiofur resistance throughout the studied period. For colistin, it was detected a resistance peak (17.5% of the strains) in the 2011-2014 period. Concerning gentamicin, 11 of 30 strains with intermediate susceptibility by the disk diffusion method were resistant by MIC. Besides, the most frequent antimicrobial resistance genes were the extended-spectrum beta-lactamase (ESBL) bla (CTX-M) (13.5% of strains, being CTX-M-14, CTX-M-1 and CTX-M-32 the most prevalent genomes, followed by CTX-M-27, CTX-M-9 and CTX-M-3), AmpC-type beta-lactamase (AmpC) bla (CMY-2) (3%) and colistin resistance genes mcr-4 (13%), mcr-1 (7%) and in less proportion mcr-5 (3%). Interestingly, these mcr genes were already detected in strains isolated in 2000, more than a decade before their first description. However, poor concordance between the genotypic mcr profile and the phenotypical testing by MIC was found in this study. These results indicate that although being a current concern, resistance genes and therefore antimicrobial resistant phenotypes were already present in pig farms at the beginning of the century. | 2020 | 32266079 |