The profile of antibiotics resistance and integrons of extended-spectrum beta-lactamase producing thermotolerant coliforms isolated from the Yangtze River basin in Chongqing. - Related Documents




#
Rank
Similarity
Title + Abs.
Year
PMID
012345
261801.0000The profile of antibiotics resistance and integrons of extended-spectrum beta-lactamase producing thermotolerant coliforms isolated from the Yangtze River basin in Chongqing. The spreading of extended-spectrum beta-lactamases (ESBL)-producing thermotolerant coliforms (TC) in the water environment is a threat to human health but little is known about ESBL-producing TCs in the Yangtze River. We received 319 ESBL-producing stains obtained from the Chongqing basin and we investigated antibiotic susceptibility, bla gene types and the presence of integrons and gene cassettes. 16.8% of TC isolates were ESBL-producing bacteria and bla(TEM+CTx-M) was the predominant ESBL type. 65.2% of isolates contained class 1 integrons, but only 3 carried intI 2. Gene cassettes were amplified and sequenced. aadA, drfA, cmlA, sat1, aar3 and two ORF cassettes were found. In conclusion, Yangtze River is heavily polluted by ESBL-producing TC bacteria and the combined bla gene type could enhance antibiotic resistance. Class 1 integrons were widespread in ESBL-producing isolates and play an important role in multi-drug resistance. Characterization of gene cassettes could reveal the dissemination of antibiotic resistance genes.201020447743
262410.9998Dissemination of ESBL-producing Escherichia coli of chicken origin to the nearby river water. The dissemination of drug-resistant bacteria from animal farms to aquatic environments can pose a potential threat to public health. In this study, antimicrobial resistance, resistance genes, and genetic similarity of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli of different origins (chicken feces and upstream and downstream river waters) were analyzed to track the spread of drug-resistant bacteria of animals. The results showed that a total of 29 ESBL-producing E. coli were obtained from 258 samples, and isolation rates of the ESBL-producing E. coli from chicken feces and upstream and downstream waters were 10.7% (16/150), 3.7% (1/27), and 14.8% (12/81), respectively. The ESBL-producing E. coli from upstream water was resistant to 7 antibiotics, but isolates from feces and downstream water had a higher resistance rate. In 29 ESBL-producing E. coli, the most common gene was CTX-M and the SHV gene was not detected. Five ESBL-producing isolates from downstream water showed >90% similarity with the fecal isolates, while the only one isolate from upstream water had <70% similarity with fecal isolates. The results suggest that animal farms' effluent, especially the untreated wastewater, could contribute to the spread of resistance genes.201425277838
262120.9998Extended Spectrum Beta-Lactamase (ESBL)-producing bacteria isolated from hospital wastewaters, rivers and aquaculture sources in Nigeria. Untreated wastewater is a risk factor for the spread of antibiotic resistance in the environment. However, little is known about the contribution of untreated wastewater to the burden of antibiotic resistance in the Nigerian environment. In this study, a total of 143 ceftazidime-/cefpodoxime-resistant bacteria isolated from untreated wastewater and untreated wastewater-contaminated surface and groundwater in Nigeria were screened for extended-spectrum β-lactamase (ESBL) genes, integrons and integron gene cassettes by PCR. The genetic environment of bla (CTX-M-15) was mapped by PCR and potentially conjugative plasmids were detected among the isolates by degenerate primer MOB typing (DPMT). ESBL production was confirmed in 114 (79.7%) isolates and ESBL genes (bla (SHV), bla (CTX-M-15) and bla (TEM)) were detected in 85 (74.6%) ESBL-producing isolates. bla (CTX-M-15) was associated with ISEcp1 and with orf477 in 12 isolates and with ISEcp1, IS26 and orf477 in six others. To the best of our knowledge, this is the first report of bla (CTX-M-15) in hand-dug wells and borehole serving as sources of drinking water and a first report of the genetic environment of bla (CTX-M-15) in environmental bacteria from Nigeria. The results of this study confirm untreated wastewater as an important medium for the spread of ESBL-producing bacteria within the Nigerian environment. Hence, the widespread practice of discharging untreated wastewater into the aquatic ecosystem in Nigeria is a serious risk to public health.201829139076
262030.9998GES-5 among the β-lactamases detected in ubiquitous bacteria isolated from aquatic environment samples. In this study, we investigated the β-lactamase-encoding genes responsible for β-lactam resistance phenotypes detected among 56 Gram-negative isolates (Gamma- and Alpha-proteobacteria) recovered from wastewater, urban streams, and drinking water. The β-lactam resistance mechanisms detected in 36 isolates comprised the presence of class A (bla(TEM)(-1) , bla(SHV)(-1) , bla(SHV)(-11) , bla(GES)(-5) ), class B (ImiS, L1), class C (bla(CMY)(-2) , bla(CMY)(-34) , bla(CMY)(-65) , bla(CMY)(-89) , bla(CMY)(-90) , bla(ACC)(-5) , bla(ACT)(-13) ), and class D (blaOXA-309)β-lactamase-encoding genes, some variants described for the first time here. Notably, the results showed antimicrobial resistance genes related not only to commonly used antibiotics, but also to carbapenems, providing the first description of a GES-5-producing Enterobacteriaceae. The importance of ubiquitous bacteria thriving in aquatic environments as reservoirs or carriers of clinically relevant resistance determinants was confirmed, and the need to monitor water habitats as potential sources for the emergence and/or spread of antibiotic resistance in the environment was highlighted.201424267783
276040.9998Extended-spectrum β-lactamase-producing bacteria and their resistance determinants in different wastewaters and rivers in Nepal. Wastewaters serve as significant reservoirs of antibiotic resistant bacteria. Despite the evidence of antimicrobial resistance in wastewaters and river water in Kathmandu, direct linkage between them is not discussed yet. This study investigated the prevalence of extended-spectrum β-lactamase (ESBL)-producing bacteria and associated resistance genes in wastewaters and river water. Out of 246 bacteria from wastewaters, 57.72% were ESBL producers and 77.64% of them were multidrug resistant (MDR). ESBL producing E. coli was dominant in municipal and hospital wastewaters (HWW) as well as in river water while K. pneumoniae was common in pharmaceutical wastewater. The bla(SHV) and bla(TEM) genes were prevalent and commonly co-occurred with aac(6')-Ib-cr in K. pneumoniae isolated pharmaceutical wastewater. bla(CTX-M) carrying E. coli from hospital co-harbored aac(6')-Ib-cr while that from municipal influent and river water co-harbored qnrS. Whole genome sequencing data revealed the presence of diverse ARGs in bacterial isolates against multiple antibiotics. In average, an E. coli and a K. pneumoniae isolate contained 55.75 ± 0.96 and 40.2 ± 5.36 ARGs, respectively. Multi-locus sequence typing showed the presence of globally high-risk clones with wider host range such as E. coli ST10, and K. pneumoniae ST15 and ST307 in HWW and river indicating frequent dissemination of antimicrobial resistance in wastewater of Kathmandu. Whole genome sequence data aligned with phenotypic antibiograms and resistance genes detected by PCR in selected isolates. The presence of significant plasmid replicons (IncF, IncY) and mobile genetic elements (IS903, IS26) indicate high frequency of spreading antibiotic resistance. These findings indicate burden and dissemination of antimicrobial resistance in the environment and highlight the need for effective strategies to mitigate the antibiotic resistance.202438795483
261950.9998Characterization of CTX-M enzymes, quinolone resistance determinants, and antimicrobial residues from hospital sewage, wastewater treatment plant, and river water. Multidrug-resistant (MDR) bacteria are widespread in hospitals and have been increasingly isolated from aquatic environments. The aim of the present study was to characterize extended-spectrum β-lactamase (ESBL) and quinolone-resistant Enterobacteriaceae from a hospital effluent, sanitary effluent, inflow sewage, aeration tank, and outflow sewage within a wastewater treatment plant (WWTP), as well as river water upstream and downstream (URW and DRW, respectively), of the point where the WWTP treated effluent was discharged. β-lactamase (bla) genes, plasmid-mediated quinolone resistance (PMQR), and quinolone resistance-determining regions (QRDRs) were assessed by amplification and sequencing in 55 ESBL-positive and/or quinolone-resistant isolates. Ciprofloxacin residue was evaluated by high performance liquid chromatography. ESBL-producing isolates were identified in both raw (n=29) and treated (n=26) water; they included Escherichia coli (32), Klebsiella pneumoniae (22) and Klebsiella oxytoca (1). Resistance to both cephalosporins and quinolone was observed in 34.4% of E. coli and 27.3% of K. pneumoniae. Resistance to carbapenems was found in 5.4% of K. pneumoniae and in K. oxytoca. Results indicate the presence of bla(CTX-M) (51/55, 92.7%) and bla(SHV) (8/55, 14.5%) ESBLs, and bla(GES) (2/55, 3.6%) carbapenemase-encoding resistance determinants. Genes conferring quinolone resistance were detected at all sites, except in the inflow sewage and aeration tanks. Quinolone resistance was primarily attributed to amino acid substitutions in the QRDR of GyrA (47%) or to the presence of PMQR (aac-(6')-Ib-cr, oqxAB, qnrS, and/or qnrB; 52.9%) determinants. Ciprofloxacin residue was absent only from URW. Our results have shown strains carrying ESBL genes, PMQR determinants, and mutations in the gyrA QRDR genes mainly in hospital effluent, URW, and DRW samples. Antimicrobial use, and the inefficient removal of MDR bacteria and antibiotic residue during sewage treatment, may contribute to the emergence and spreading of resistance in the environment, making this a natural reservoir.201727816836
262760.9997High Prevalence of Drug Resistance and Class 1 Integrons in Escherichia coli Isolated From River Yamuna, India: A Serious Public Health Risk. Globally, urban water bodies have emerged as an environmental reservoir of antimicrobial resistance (AMR) genes because resistant bacteria residing here might easily disseminate these traits to other waterborne pathogens. In the present study, we have investigated the AMR phenotypes, prevalent plasmid-mediated AMR genes, and integrons in commensal strains of Escherichia coli, the predominant fecal indicator bacteria isolated from a major urban river of northern India Yamuna. The genetic environment of bla (CTX-M-15) was also investigated. Our results indicated that 57.5% of the E. coli strains were resistant to at least two antibiotic classes and 20% strains were multidrug resistant, i.e., resistant to three or more antibiotic classes. The multiple antibiotic resistance index of about one-third of the E. coli strains was quite high (>0.2), reflecting high contamination of river Yamuna with antibiotics. With regard to plasmid-mediated AMR genes, bla (TEM-1) was present in 95% of the strains, followed by qnrS1 and armA (17% each), bla (CTX-M-15) (15%), strA-strB (12%), and tetA (7%). Contrary to the earlier reports where bla (CTX-M-15) was mostly associated with pathogenic phylogroup B2, our study revealed that the CTX-M-15 type extended-spectrum β-lactamases (ESBLs) were present in the commensal phylogroups A and B1, also. The genetic organization of bla (CTX-M-15) was similar to that reported for E. coli, isolated from other parts of the world; and ISEcp1 was present upstream of bla (CTX-M-15). The integrons of classes 2 and 3 were absent, but class 1 integron gene intI1 was present in 75% of the isolates, denoting its high prevalence in E. coli of river Yamuna. These evidences indicate that due to high prevalence of plasmid-mediated AMR genes and intI1, commensal E. coli can become vehicles for widespread dissemination of AMR in the environment. Thus, regular surveillance and management of urban rivers is necessary to curtail the spread of AMR and associated health risks.202133633708
262370.9997High Carriage of Extended-Spectrum, Beta Lactamase-Producing, and Colistin-Resistant Enterobacteriaceae in Tibetan Outpatients with Diarrhea. Antibiotic-resistant bacteria (ARB) and antibiotic-resistance genes (ARGs) have been detected in human-impacted habitats, especially in densely populated cities. The Qinghai-Tibet Plateau is located far from the heavily populated regions of China, and Tibetan residents have distinct dietary habits and gut microbes. Antibiotic-resistance monitoring in the Tibetan population is rare. Here, we collected stool samples from Tibetan outpatients with diarrhea. From 59 samples, 48 antibiotic-resistant Enterobacteriaceae isolates were obtained, including 19 extended-spectrum beta lactamase (ESBL)-producing isolates from 16 patients and 29 polymyxin-resistant isolates from 22 patients. Either ESBL or mcr genes were found in 17 Escherichia coli isolates, approximately 58.8% of which were multidrug-resistant, and ten incompatible plasmid types were found. The gene bla(CTX-M) was a common genotype in the ESBL-producing E. coli isolates. Four E. coli isolates contained mcr-1. The same mcr-1-carrying plasmid was found in distinct E. coli isolates obtained from the same sample, thus confirming horizontal transmission of mcr-1 between bacteria. Genomic clustering of E. coli isolates obtained from Lhasa, with strains from other regions providing evidence of clone spreading. Our results reveal a strong presence of ARB and ARGs in Tibetan outpatients with diarrhea, implying that ARB and ARGs should be monitored in the Tibetan population.202235453259
207080.9997Complex integrons containing qnrB4-ampC (bla(DHA-1)) in plasmids of multidrug-resistant Citrobacter freundii from wastewater. Microbial populations in wastewater treatment plants (WWTPs) are increasingly being recognized as environmental reservoirs of antibiotic resistance genes. PCR amplicons for plasmid-mediated quinolone resistance determinants qnrA, qnrB, and qnrS were recorded in samples from a WWTP in Vancouver, British Columbia. Six strains of ciprofloxacin-resistant Citrobacter freundii were isolated and found to carry mutations in gyrA and parC, as well as multiple plasmid-borne resistance genes, collectively including qnrB; aac(6')-Ib-cr; β-lactamase-encoding genes from molecular classes A (blaTEM-1), C (ampC), D (blaOXA-1, blaOXA-10); and genes for resistance to 5 other types of antibiotics. In 3 strains, large (>60 kb) plasmids carried qnrB4 and ampC as part of a complex integron in a 14 kb arrangement that has been reported worldwide but, until recently, only among pathogenic strains of Klebsiella. Analysis of single-nucleotide polymorphisms in the qnrB4-ampC regions infers 2 introductions into the WWTP environment. These results suggest recent passage of plasmid-borne fluoroquinolone and β-lactam resistance genes from pathogens to bacteria that may be indigenous inhabitants of WWTPs, thus contributing to an environmental pool of antibiotic resistance.201323461518
118890.9997High Prevalence of Plasmid-Mediated Quinolone Resistance and IncQ Plasmids Carrying qnrS2 Gene in Bacteria from Rivers near Hospitals and Aquaculture in China. Effluents from hospital and aquaculture are considered important sources of quinolone resistance. However, little information is available on the impact of this effluent on nearby rivers. In this study, 188 ciprofloxacin-resistant bacterial isolates obtained from rivers near hospitals and aquaculture were screened for plasmid-mediated quinolone resistance (PMQR) genes. Species identification, antibiotic susceptibility testing, and PMQR gene transferability assessment were conducted for PMQR-positive bacteria. Representative qnrS2-encoding plasmids were subsequently sequenced using a primer-walking approach. In total, 44 isolates (23.4%) were positive for qnr genes (16 qnrB2, 3 qnrS1, and 25 qnrS2) and 32 isolates (17.0%) were positive for aac(6')-Ib-cr. Other PMQR genes were not detected. The qnrB2 and aac(6')-Ib-cr genes had a higher prevalence in aquaculture samples than in hospital samples, and were significantly associated with Enterobacteriaceae (p < 0.05). In contrast, the prevalence of qnrS2 was not site-related, but was significantly associated with Aeromonas spp. (p < 0.05). All PMQR isolates were resistant to three or more classes of antibiotics. Eleven qnrS2-harboring plasmids from Aeromonas spp., including a novel conjugative plasmid pHP18, were selected for sequencing. These plasmids were small in size (6,388-16,197 bp) and belonged to the IncQ or IncU plasmid family, with qnrS2 being part of a mobile insertion cassette. Taken together, our findings suggest that aquaculture is a possible source for aac(6')-Ib-cr and qnrB2 dissemination, and demonstrate the ubiquity of qnrS2 in aquatic environments. Finally, Aeromonas spp. served as vectors for qnrS2 with the help of IncQ-type plasmids.201627427763
2625100.9997Spread of extended-spectrum beta-lactamase-producing Escherichia coli from a swine farm to the receiving river. The dissemination of drug-resistant bacteria into different environments has posed a grave threat to public health, but data on the spread of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) from animal farms to the receiving river are limited. Here, 57 ESBL-producing E. coli isolated from a pig farm and the receiving river were analyzed in terms of drug resistance, ESBL genes, and enterobacterial repetitive intergenic consensus (ERIC). The results showed that ESBL-producing E. coli from swine feces and downstream water of the pig farm outfall overlapped substantially in drug resistance and ESBL genes. Additionally, six ESBL-producing E. coli from the downstream water exhibited 100 % genetic similarity with strains from the swine feces. In conclusion, effluents of animal farms are a likely contributor to the presence of ESBL-producing E. coli in aquatic environments.201525921760
2628110.9997Occurrence and persistence of multidrug-resistant Enterobacterales isolated from urban, industrial and surface water in Monastir, Tunisia. The One Health approach of antimicrobial resistance highlighted the role of the aquatic environment as a reservoir and dissemination source of resistance genes and resistant bacteria, especially due to anthropogenic activities. Resistance to extended-spectrum cephalosporins (ESC) conferred by extended-spectrum beta-lactamases (ESBLs) in E. coli has been proposed as the major marker of the AMR burden in cross-sectoral approaches. In this study, we investigated wastewater, surface water and seawater that are subjected to official water quality monitoring in Monastir, Tunisia. While all but one sample were declared compliant according to the official tests, ESC-resistant bacteria were detected in 31 (19.1 %) samples. Thirty-nine isolates, coming from urban, industrial and surface water in Monastir, were collected and characterized using antibiograms and whole-genome sequencing. These isolates were identified as 27 Escherichia coli (69.3 %) belonging to 13 STs, 10 Klebsiella pneumoniae (25.6 %) belonging to six STs, and two Citrobacter freundii (5.1 %). We observed the persistence and dissemination of clones over time and in different sampling sites, and no typically human-associated pathogens could be identified apart from one ST131. All isolates presented a bla(CTX-M) gene - bla(CTX-M-15) (n = 22) and bla(CTX-M-55) (n = 8) being the most frequent variants - which were identified on plasmids (n = 20) or on the chromosome (n = 19). In conclusion, we observed ESC resistance in rather ubiquitous bacteria that are capable of surviving in the water environment. This suggests that including the total coliform count and the ESBL count as determined by bacterial growth on selective plates in the official monitoring would greatly improve water quality control in Tunisia.202438460700
1616120.9997Characterization of Extended-Spectrum β-Lactamase-Producing Escherichia coli Isolated from Fresh Produce and Agricultural Environments in Korea. ABSTRACT: This study was conducted to characterize Escherichia coli strains and evaluate the spread of antimicrobial resistance among these strains from fresh produce and farm environments in Korea. We then conducted phenotypic and genetic studies on antimicrobial-resistant isolates. We determined the genetic epidemiological characteristics of isolates that produced extended-spectrum β-lactamase (ESBL) and confirmed plasmid transfer in isolates that carried blaCTX-M-type genes. E. coli strains were isolated from 8 samples of fresh produce and 152 samples from the farm environment collected from May 2014 to June 2016. Cephalosporin resistance was the most prevalent (61.8%) type of resistance among the isolates. Five ESBL-producing strains with high genetic homology with E. coli of human or livestock origin were identified. Lateral transfer of plasmids harboring blaCTX-M-type genes to transconjugants was successful. Two isolates from Chinese cabbage and from water samples collected from a nearby stream harbored the ISEcp1-blaCTX-M-55-orf477 operon and were confirmed as sequence type 1196 and the same type of plasmid replicon, suggesting that cross-contamination was highly likely. A high-risk clone of sequence type 69 (clonal complex 69) isolates was also recovered from the farm environment. This study provides genetic evidence that antimicrobial resistance factors in E. coli from farm environments originate in the clinic or in livestock, highlighting the fact that good agricultural practices in farming are important to inhibit the spread of antimicrobial resistance to bacteria on fresh produce.202032083678
2048130.9997The Role of Plasmids in the Multiple Antibiotic Resistance Transfer in ESBLs-Producing Escherichia coli Isolated From Wastewater Treatment Plants. We compared the diversity of extended-spectrum β-lactamases (ESBLs) producing Escherichia coli (E. coli) in wastewater of a municipal wastewater treatment plant. This was done by analyzing multiple antibiotic resistant phenotypes and genotypes. Also, we investigated the antibiotic resistance transfer mechanism of the plasmid by comparing the antibiotic resistance gene linked transfer using a conjugative test, and by analyzing the full-length DNA sequence of one plasmid. The results showed that 50 ESBLs-producing E. coli isolates were isolated from 80 wastewater samples at the rate of 62.5% (50/80), out of which 35 transconjugants were obtained with the multiple antibiotic resistant transfer rate as high as 70.0% (35/50). Multiple antibiotic resistance was shown in all transconjugants and donor bacteria, which were capable of resistance to 11 out of 15 kinds of antibiotics. Both transconjugants and donors were capable of resistance to the Ampicillin and Cefalotin at a rate of 100.00% (35/35), while the total antibiotic resistant spectrum of transconjugants narrowed at the rate of 94.29% (33/35) and broadened at the rate of 5.71% (2/35) after conjugate to the donor bacteria. PCR showed that the resistant genotypes decreased or remained unchanged when compared to donor bacteria with transconjugants while the bla(TEM) and bla(CTX-M) genes were transferred and linked at a rate of 100.00% (35/35) and the bla(SHV) gene was at the rate as high as 94.29% (33/35). However, the qnrS gene was transferred at a low rate of 4.17% (1/24). In addition, the major resistance gene subtypes were bla(TEM-) (1), bla(SHV -11) , and bla(CTX-M-15) according to sequencing and Blast comparison. Plasmid wwA8 is a closed-loop DNA molecule with 83157 bp, and contains 45 predicted genes, including three antibiotic resistant resistance genes, bla(CTX-M-15) , bla(TEM-1) and qnrS1, which can be transferred with E. coli in vitro. This study shows that E. coli isolated from wastewater was capable of transferring resistance genes and producing antibiotic resistant phenotypes. The plasmids containing different resistance genes in E. coli play an important role in the multiple antibiotic resistant transfer. Most importantly, antibiotic resistant resistance genes have different transfer efficiencies, the bla(TEM) and bla(CTX-M) genes transferred at a rate of 100.00% and linked transfer in all 35 transconjugants.201931001218
2635140.9997Presence and Diversity of Extended-Spectrum Cephalosporin Resistance Among Escherichia coli from Urban Wastewater and Feedlot Cattle in Alberta, Canada. A recent preliminary study from our group found that extended-spectrum cephalosporin-resistance determinants can be detected in the majority of composite fecal samples collected from Alberta feedlot cattle. Most notably, bla(CTX-M) genes were detected in 46.5% of samples. Further isolate characterization identified bla(CTX-M-15) and bla(CTX-M-27), which are widespread in bacteria from humans. We hypothesized that Escherichia coli of human and beef cattle origins share the same pool of bla(CTX-M) genes. In this study, we aimed to assess and compare the genomic profiles of a larger collection of bla(CTX-M)-positive E. coli recovered from fecal composite samples from Canadian beef feedlot cattle and human wastewater through whole-genome sequencing. The variants bla(CTX-M-55), bla(CTX-M-32), bla(CTX-M-27), bla(CTX-M-15), and bla(CTX-M-14) were found in both urban wastewater and cattle fecal isolates. Core genome multilocus sequence typing showed little similarity between the fecal and wastewater isolates. Thus, if the dissemination of genes between urban wastewater and feedlot cattle occurs, it does not appear to be related to the expansion of specific clonal lineages. Further investigations are warranted to assemble and compare plasmids carrying these genes to better understand the modalities and directionality of transfer.202031553261
2054150.9997A survey of plasmid-mediated fluoroquinolone resistance genes from Escherichia coli isolates and their dissemination in Shandong, China. Bacterial resistance to fluoroquinolones result from mutations in the quinolone resistance-determining regions of the drug targets, overexpression of efflux pumps, and/or the more recently identified plasmid-mediated low-level resistance mechanisms. We investigated the prevalence of and characterized plasmid-mediated fluoroquinolone resistance genes (qnrA, qnrB, qnrS, aac(6')-Ib-cr, and qepA) by polymerase chain reaction in fluoroquinolone-resistant Escherichia coli (n = 530) isolated from a chicken farm, a pig farm, and hospitalized patients in Shandong, China, in 2007. The aac(6')-Ib-cr gene was the most prevalent resistance gene that was detected in bacteria isolated from all sources. Next was the qnrS gene, which was predominantly present in isolates from the pig farm. Only eight (5.8%) isolates from hospital patients were found to possess the qepA gene, and these isolates were first reported in qepA-carrying E. coli from humans in China. The qnrA and qnrB genes were not detected in any of the isolates. Further, most of the isolates were also resistant to beta-lactams and aminoglycosides as determined by the broth microdilution method. Pulsed-field gel electrophoresis analysis of the E. coli isolates with similar resistance patterns that also carried resistance genes showed great genomic diversity among these bacteria, suggesting that the multiresistant E. coli isolates carrying the qnr, aac(6')-Ib-cr, or qepA genes were not derived from a specific clone, but represented a wide variety of different genotypes. The results of Southern hybridization revealed that qepA, qnrS, and parts of aac(6')-Ib-cr genes were localized on plasmids and/or chromosome. qepA and aac(6')-Ib-cr genes were colocalized with aac(6')-Ib-cr and qnrS genes, respectively, on the same plasmids. Our study demonstrated that two different genes (qepA and aac(6')-Ib-cr) were identified on the same plasmid in E. coli strains derived from patients and qnrS and aac(6')-lb-cr genes on the same plasmid in an E. coli strain of animal origin.201019911944
2617160.9997Mossambicus tilapia (Oreochromis mossambicus) collected from water bodies impacted by urban waste carries extended-spectrum beta-lactamases and integron-bearing gut bacteria. Oreochromis mossambicus (Peters 1852) (Tilapia) is one of the most consumed fish globally. Tilapia thrives well in environments polluted by urban waste, which invariably contain antibiotic-resistant bacteria and antibiotic resistance genes (ARGs). Thus, Tilapia surviving in such polluted environments may serve as a potential source for dissemination of ARGs. To investigate this, we isolated bacterial strains from gut of Tilapia found in polluted rivers and lakes near Pune, India, and studied the prevalence of resistance genes by molecular methods. A total of 91 bacterial strains were obtained, which include fish pathogens and human pathogens such as Aeromonas hydrophila, Klebsiella pneumoniae, E. coli, Serratia marcescens, Enterobacter spp. and Shigella spp. Overall the prevalence of class 1 integrons, class 2 integrons, extended-spectrum betalactamases (ESBLs) blaCTX-M, blaSHV and aac(6')-Ib-cr gene was 38 percent, 24 percent, 38 percent, 31 percent and 31 percent respectively. Forty-two percent of the Enterobacteriaceae strains carried blaCTX-M gene, which is a common ESBL gene in clinics. The study demonstrates that tilapia found in the polluted waters can serve as reservoirs and an alternative route for human exposure to clinically important ARG-carrying bacteria. The consumption and handling of these fish may pose a potential health risk.201627581926
2022170.9997Analysis of antimicrobial resistance genes detected in multiple-drug-resistant Escherichia coli isolates from broiler chicken carcasses. Multi-drug-resistant (MDR) bacteria in food animals are a potential problem in both animal and human health. In this study, MDR commensal Escherichia coli isolates from poultry were examined. Thirty-two E. coli isolates from broiler carcass rinses were selected based on their resistance to aminoglycosides, β-lactams, chloramphenicols, tetracyclines, and sulfonamide antimicrobials. Microarray analysis for the presence of antimicrobial resistance and plasmid genes identified aminoglycoside [aac(6), aac(3), aadA, aph, strA, and strB], β-lactam (bla(AmpC), bla(TEM), bla(CMY), and bla(PSE-1)), chloramphenicol (cat, flo, and cmlA), sulfamethoxazole (sulI and sulII), tetracycline [tet(A), tet(C), tet(D), and tetR], and trimethoprim (dfrA) resistance genes. IncA/C plasmid core genes were detected in 27 isolates, while IncHI1 plasmid genes were detected in one isolate, indicating the likely presence of these plasmids. PCR assays for 18 plasmid replicon types often associated with MDR in Enterobacteriaceae also detected one or more replicon types in all 32 isolates. Class I integrons were investigated by PCR amplification of the integrase I gene, intI1, and the cassette region flanked by conserved sequences. Twenty-five isolates were positive for the intI1 gene, and class I integrons ranging in size from ~1,000 to 3,300 bp were identified in 19 of them. The presence of class I integrons, IncA/C plasmid genes, and MDR-associated plasmid replicons in the isolates indicates the importance of these genetic elements in the accumulation and potential spread of antimicrobial resistance genes in the microbial community associated with poultry.201222385320
2764180.9997Solid waste dumpsite leachate and contiguous surface water contain multidrug-resistant ESBL-producing Escherichia coli carrying Extended Spectrum β-Lactamase (ESBL) genes. Dumpsites generate leachates containing bacteria that may carry antibiotic resistance genes, such as extended spectrum β-lactamase (ESBL). However, the contribution of dumpsite leachates in the environmental spread of ESBL genes has not been investigated in greater detail. This study aimed to quantify the impact of Ajakanga dumpsite leachate on the spread of ESBL genes through surface water. The susceptibility of Escherichia coli isolated from dumpsite leachate and the accompanying surface water to selected antibiotics was assessed by the standardized disc diffusion method. The isolates were evaluated for phenotypic ESBL production using the double disc synergy test (DDST). The detection of ESBL genes in the isolates was carried out using a primer-specific polymerase chain reaction (PCR). Escherichia coli isolates from leachate (n = 26/32) and surface water (n = 9/12) expressed ESBL phenotype. The ESBL-producing isolates showed the highest level of resistance to the 3rd generation cephalosporin antibiotics: cefotaxime (100%), cefpodoxime (97%), ceftazidime (97%), with low resistance observed to imipenem (6%) and azithromycin (3%). All the isolates were multidrug-resistant, showing resistance to three or more classes of antibiotics. All the ESBL-producing E. coli obtained carried bla(CTX-M), 21/35 (60%) carried bla(TEM) while none of the isolates bore bla(SHV). This study found that ESBL-producing Escherichia coli from dumpsite leachate and nearby surface water had identical resistance signatures indicating the relatedness of the isolates, and that dumpsite leachate could contribute to the transfer of ESBL-producing bacteria and their genes to receiving surface water. This study has necessitated the need for a review of the guidelines and operational procedures of dumpsites to forestall a potential public health challenge.202439164664
1036190.9997Detection of carbapenem resistance genes and cephalosporin, and quinolone resistance genes along with oqxAB gene in Escherichia coli in hospital wastewater: a matter of concern. AIMS: This study was performed to detect the presence of Escherichia coli resistant to cephalosporins, carbapenems and quinolones in hospital wastewater. METHODS AND RESULTS: Wastewaters from a rural (H1) and an urban (H2) hospital were tested for E. coli resistant to cephalosporins, carbapenem and quinolones. Genes coding for chromosomal and plasmid-mediated resistance and phylogenetic grouping was detected by multiplex polymerase chain reaction (PCR) and for genetic relatedness by rep-PCR. Of 190 (H1 = 94; H2 = 96) E. coli examined, 44% were resistant to both cephalosporins and quinolones and 3% to imipenem. ESBLs were detected phenotypically in 96% of the isolates, the gene blaCTX-M coding for 87% and blaTEM for 63%. Quinolone resistance was due to mutations in gyrA and parC genes in 97% and plasmid-coded aac-(6')-Ib-cr in 89% of isolates. Only in one carbapenem-resistant E. coli, NDM-1 was detected. Nearly 67% of the isolates belonged to phylogenetic group B2. There was no genetic relatedness among the isolates. CONCLUSIONS: Hospital wastewater contains genetically diverse multidrug-resistant E. coli. SIGNIFICANCE AND IMPACT OF THE STUDY: This study stresses the need for efficient water treatment plants in healthcare settings as a public health measure to minimize spread of multidrug-resistant bacteria into the environment.201424975198