Co-occurrence of mcr-1, mcr-3, mcr-7 and clinically relevant antimicrobial resistance genes in environmental and fecal samples. - Related Documents




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119001.0000Co-occurrence of mcr-1, mcr-3, mcr-7 and clinically relevant antimicrobial resistance genes in environmental and fecal samples. Multidrug-resistant bacteria harboring different antimicrobial resistance genes (ARGs) have been detected worldwide. The association of plasmid-mediated colistin resistance genes (mcr-like) and other ARGs in bacteria isolated from animals is a huge concern worldwide. Therefore, this study aimed to investigate the presence of mcr-like genes and clinically relevant ARGs as well as plasmids in samples from a zoo. Fecal and environmental (soil and water) samples were collected from a zoo and the DNA of cultivable aerobic bacteria was extracted. ARGs were screened by PCR and the plasmids were detected using the PCR-based replicon typing method. A total of 74 amplicons from 27 ARGs [mcr-1, mcr-3, mcr-7.1, bla(CTX-M-Gp1), bla(CTX-M-Gp2), bla(CTX-M-Gp9), bla(VEB), bla(PER), bla(CMY), tetA, tetB, tetC, aadA, aac(6')-Ib, aph(3')-Ia, ant(2'')-Ia, qnrA, qnrB, qnrS, oqxA, oqxB, sul1, sul2, sul3, cmlA, mefAE, ermB] and 21 amplicons from eight plasmid families (IncY, ColE-like, IncF(repB), IncFIA, IncFIB, IncHI1, IncFIC, IncP) were detected. These findings reinforce that the zoo acts as a reservoir of clinically relevant ARGs, including mcr-like, and call attention to the monitoring studies in the zoo. Therefore, to the best of our knowledge, this is the first report of the world of mcr-1, mcr-3 and mcr-7.1 in environmental samples from the zoo.202032382766
119110.9998IncFII plasmid carrying antimicrobial resistance genes in Shigella flexneri: Vehicle for dissemination. OBJECTIVES: Plasmids harbouring antimicrobial resistance determinants in clinical strains are a significant public-health concern worldwide. The present study investigated such plasmids in clinical isolates of Shigella flexneri. METHODS: A total of 162 Shigella isolates were obtained from stool specimens in the year 2015. Among the 70 multidrug-resistant (MDR) Shigella spp., 27 S. flexneri isolates were randomly selected for further characterisation. Antimicrobial resistance genes (ARGs) and plasmid incompatibility (Inc) types were analysed. RESULTS: IncFII plasmids were found in 63% (17/27) of the studied S. flexneri isolates. ARGs such as dhfr1a (81%), sulII (74%), bla(OXA) (74%), bla(TEM) (33%), bla(AmpC) (30%), qnrS (15%) and qnrB (4%) were identified by PCR, whereas bla(CTX-M) was not detected. Next-generation sequencing of a representative S. flexneri IncFII-type plasmid (pSF470) revealed the presence of bla(TEM1-B), bla(DHA-1), qnrB10, mphA, sulI, sulII, strA, strB and tetR ARGs along with the intI1 integrase gene. In addition, pMLST analysis showed that the replicon belonged to F2:A-:B- type. CONCLUSIONS: This study helps to know the prevalent plasmid types in MDR Shigella isolates and will improve our understanding of resistance dissemination among enteric bacteria. ARGs in plasmids further highlight the importance of such studies in enteric bacteria.201930342929
96120.9998Predominance of CTX-M-15 among ESBL Producers from Environment and Fish Gut from the Shores of Lake Victoria in Mwanza, Tanzania. Extended-Spectrum Beta-Lactamase (ESBL)-producing bacteria are a common cause of healthcare and community-associated infections worldwide. The distribution of such isolates in the environment and their presence in fish as a result of sewage contamination is not well-studied. Here we examined fish and environmental samples from Mwanza city for the presence of ESBL-producing bacteria. From 196 fish sampled from local markets, 26 (13.3%) contained lactose-fermenting ESBL-producing bacteria, while 39/73 (53.4%) environmental samples from the same area were ESBL producers. Antibiotic resistance genes, multi locus sequence types (MLST) and plasmid replicon types in 24 selected isolates from both populations were identified with whole genome sequencing using Illumina MiSeq. Nine of eleven sequenced fish isolates had the bla(CTX-M-15) gene whereas 12/13 from environment carried bla(CTX-M-15). Antibiotic resistance genes encoding resistance to sulfonamides (sul1/sul2), tetracyclines [tet(A)/tet(B)] fluoroquinolones [e.g., aac(6')-Ib-cr, qnrS1], aminoglycosides [e.g., aac(3)-lld, strB, strA,] and trimethoprim (e.g., dfrA14) were detected. E. coli sequence type ST-38 (2) and ST-5173 (2) were detected in isolates both from the environment and fish. IncY plasmids carrying bla(CTX-M-15), qnrS1, strA, and strB were detected in five environmental E. coli isolates and in one E. coli isolate from fish. Our data indicate spillage of resistant environmental isolates into Lake Victoria through the sewage system. Persistence of bla(CTX-M-15) in the Mwanza city environment is complex, and involves both clonal spread of resistant strains as well as dissemination by commonly occurring IncY plasmids circulating in isolates present in humans, the environment as well as in the food chain.201627990135
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
90340.9997Carbapenemase and ESBL genes with class 1 integron among fermenting and nonfermenting bacteria isolated from water sources from India. The present study was aimed to detect the carbapenemase, extended-spectrum β-lactamase (ESBL), and intI1 gene of class 1 integron among fermenting (n = 61) and nonfermenting (n = 10) bacterial isolates recovered from water samples (n = 128). Isolates were identified by 16S rRNA sequencing. These isolates showed reduced-susceptibility to third-generation cephalosporins and carbapenems. The isolates varied in number and size of plasmids (2 kb to >20 kb). Plasmid DNA screening showed 5·6, 7, 11·2 and 26·7% prevalence of bla(KPC) , bla(NDM) , bla(SHV) and bla(TEM) genes respectively. Diverse bla(NDM) (bla(NDM-1) and bla(NDM-4) ) and bla(SHV) subtypes (bla(SHV-2) and bla(SHV-11) ) were recorded, unlike the single allelic bla(KPC) (bla(KPC-2) ) and bla(TEM) (bla(TEM-1) ) gene. Of the total 27 bla-gene-producing bacterial isolates, seven isolates co-harboured the carbapenemase genes (bla(NDM) or bla(KPC) or the both) along with the ESBL genes (bla(SHV) or bla(TEM) ). The intI1 gene of class 1 integron was detected among 12 (44·4%) of ESBL- and/or carbapenemase-harbouring isolates. Gene transferability was seen among four of the 10 Enterobacteriaceae donors. Carbapenemases and ESBLs with class 1 integron among aquatic environmental isolates raise the serious issue of the biosecurity and health of the ecosystem. SIGNIFICANCE AND IMPACT OF THE STUDY: Anthropologically affected and polluted environment harbours the resistance threats, where a diverse bacterial species maintain, develop and exchange genetic determinants that constitute a risk to human and ecological health. The antimicrobial resistance (AMR) in Enterobacteriaceae and non-Enterobacteriaceae bacteria caused the failure of the therapy of last resort (carbapenems) and thus lead to life-threatening infections affecting public health. Surveillance and monitoring of AMR could be important for epidemiological, diagnostic testing and control of pathogens. This is a point-prevalence study reporting the comparative occurrence and co-occurrence of carbapenemase and extended-spectrum β-lactamase genes among fermenting and nonfermenting bacteria isolated from the aquatic environment in India.202031587338
110450.9997Predominance of Multidrug-Resistant Gram-Negative Bacteria Isolated from Supermarket Retail Seafood in Japan. Reports have documented antimicrobial usage in aquaculture, and the aquatic ecosystem can be considered a genetic storage site for antibiotic-resistant bacteria. This study assessed the prevalence of antimicrobial resistance (AMR) among Gram-negative bacteria recovered from retail seafood in Hiroshima, Japan. A total of 412 bacteria were isolated and screened for the presence of β-lactamases, acquired carbapenemases, and mobile colistin-resistance (mcr) genes. Forty-five (10.9%) isolates were dominated by Morganella (28%), Proteus (22%), Aeromonas (14%), Citrobacter (8%), and Escherichia (8%) and carried AMR genes. The identified AMR genes included those encoded in integrons (19), aac(6՛)-Ib (11), bla(TEM-1) (7), bla(CTX-M-like) (12), bla(CTX-M-65) (2), bla(SHV-12) (1), bla(SHV-27) (1), bla(OXA-10) (1), bla(OXA-2) (1), and mcr (2). The most common clinical resistances were against ampicillin, colistin, sulfamethoxazole/trimethoprim, tetracycline, and ciprofloxacin. Multidrug resistance (MDR) occurred in 27 (60%) AMR isolates, and multiple antibiotic resistance indices ranged from 0.2 to 0.8. A conjugation experiment showed that 10 of the 11 selected MDR strains harbored conjugable plasmids, although PCR-based replicon typing described seven strains as untypable. IncF replicon was identified in MDR extended-spectrum β-lactamase-producing Escherichia coli of the pathogenic B2 phylogroup. Our findings suggest that retail seafood harbors MDR bacteria of human interest that require strict resistance surveillance in the seafood production continuum.202338138079
294860.9997Fecal cultivable aerobic microbiota of dairy cows and calves acting as reservoir of clinically relevant antimicrobial resistance genes. Antimicrobial resistance has become a global threat to public health since multidrug-resistant (MDR) bacteria have been reported worldwide carrying different antimicrobial resistance genes (ARGs), and animals have been described as a reservoir of ARGs. The presence of antimicrobial-resistant bacteria and ARGs in the food matrix is a risk to public health. This study aimed to research the presence of clinically relevant ARGs for important antimicrobials and genetic elements in fecal samples from dairy cows and calves on a Brazilian farm. In this study, a total of 21 fecal samples were collected, and then, the DNA of cultivable aerobic bacteria was extracted. Fifty-seven ARGs and twenty-three genetic elements were researched by PCR and confirmed by sequencing. Several ARGs that confer resistance to β-lactams, tetracyclines, fluoroquinolones, sulphonamides, phenicols, aminoglycoside, glycopeptides, and macrolides were detected. A total of 200 amplicons from 23 ARGs (bla(CTX-M-Gp2), bla(CMY), bla(SHV), tetA, tetB, tetC, qepA, qnrB, qnrS, oqxA, oqxB, vanC1, vanC2/3, aadA, sul1, sul2, sul3, ermB, mefAE, floR, cmlA, aadA, aph(3')-Ia, aac(3')-Ia), and 145 amplicons from 12 genetic elements (IncF, IncFIA, IncFIB, IncI1, IncY, IncU, IncK, IncP, IncR, IncHI1, ColE-like, intI1) were detected. The results presented in this study call attention to the monitoring of antimicrobial resistance in dairy farms worldwide. MDR bacteria and ARGs can spread to different sources, including milk products, which are one of the most consumed products worldwide, representing a potential risk to human health.202032246396
108970.9997Diversity of plasmids harboring bla(CMY-2) in multidrug-resistant Escherichia coli isolated from poultry in Brazil. Multidrug-resistance (MDR) has been increasingly reported in Gram-negative bacteria from the intestinal microbiota, environment and food-producing animals. Resistance plasmids able to harbor different transposable elements are capable to mobilize antimicrobial resistance genes and transfer to other bacterial hosts. Plasmids carrying bla(CMY) are frequently associated with MDR. The present study assessed the presence of plasmid-encoded ampC genes (bla(cmy), bla(mox), bla(fox), bla(lat), bla(act), bla(mir), bla(dha), bla(mor)) in commensal E. coli isolated from apparently healthy broiler chickens. Furthermore, we characterized the plasmids and identified those harboring the resistance genes. We isolated 144/200 (72%) of E. coli isolates with resistance to cefotaxime and the resistance gene identified was bla(CMY-2). The pulsed-field gel electrophoresis (PFGE) analysis showed high diversity of the genetic profiles. The phylogenetic groups A, B1, B2, and D were identified among E. coli isolates and group D was the most prevalent. The PCR-based replicon typing (PBRT) analysis identified four distinct plasmid incompatibility groups (Inc) in MDR isolates. Moreover, plasmids harboring bla(CMY-2), ranged in size from 50kb to 150kb and 51/144 (35%) belonged to IncK, 21/144 (14.5%) to IncB/O, 8/144 (5.5%) to IncA/C, 1/144 (0.5%) to IncI, while 63/144 (44.5%) were not typeable by PBRT. Overall, a high prevalence of bla(CMY-2) genes was found in a diverse population of commensal MDR E. coli from poultry in Brazil, harbored into different plasmids.201728602519
109380.9997The rate of frequent co-existence of plasmid-mediated quinolone resistance (PMQR) and extended-spectrum β-lactamase (ESBL) genes in Escherichia coli isolates from retail raw chicken in South Korea. Since plasmid-encoded antibiotic resistance facilitates the emergence of antibiotic-resistant bacteria, the increasing prevalence of Escherichia coli harboring plasmid-mediated quinolone resistance (PMQR) and extended-spectrum β-lactamase (ESBL) genes is a public health concern. The objective of this study is to investigate the co-existence of PMQR and ESBL genes in E. coli isolates from retail raw chicken in South Korea. Among 67 ESBL-producing E. coli isolates from 40 retail raw chicken, more than half of them carried PMQR genes, including qnrS, aac(6')-Ib-cr, and oqxAB. The qnrS was predominantly (91.4%) detected in E. coli isolates carrying both PMQR and ESBL. The aac(6')-Ib-cr was detected in seven ESBL-producing E. coli strains, and 85.7% of the aac(6')-Ib-cr-positive strains also carried qnrS. Moreover, the strains co-harboring qnrS and aac(6')-Ib-cr exhibited increased resistance to ciprofloxacin and kanamycin. These results demonstrate that PMQR genes are frequently detected in ESBL-producing E. coli isolates from retail raw chicken in South Korea.202235646407
96990.9997Dissemination of the rmtB gene carried on IncF and IncN plasmids among Enterobacteriaceae in a pig farm and its environment. OBJECTIVES: To investigate the prevalence and characterization of 16S rRNA methylase-producing bacteria in a pig farm and its environment in East China. METHODS: Enterobacteriaceae isolates and metagenomic DNA from 102 pig faecal samples from a pig farm and 97 soil samples taken in or around the farm were screened for the presence of 16S rRNA methylase genes. The clonal relationships of 16S rRNA methylase-positive isolates, plasmid content and other associated resistance genes were also characterized. RESULTS: Fifty-six rmtB-positive Enterobacteriaceae isolates, including 54 Escherichia coli, 1 Morganella morganii and 1 Proteus mirabilis, were recovered from 55 pig faecal samples. Nineteen rmtB-positive bacteria, including 13 E. coli, 2 M. morganii, 2 Leclercia adecarboxylata, 1 Enterobacter aerogenes and 1 Enterobacter cloacae, were recovered from 16 soil samples. Among the 75 rmtB-positive isolates, 31 and 25 also carried the qepA and bla(CTX-M) genes, respectively. The qepA gene co-localized with rmtB on the F2:A-:B1 plasmids and the bla(CTX-M-65) gene co-localized with rmtB on the F33:A-:B- plasmids. The rmtB gene was also found to be associated with the IncN plasmids. Clonal transmission of rmtB-positive E. coli isolates was observed between different pig groups and soil samples. CONCLUSIONS: Both horizontal gene transfer and clonal spread could be responsible for the dissemination of the rmtB gene in the pig farm and its environment. To our knowledge, this study is the first report of rmtB-positive bacteria from farmland soils and indicates that these antibiotic-resistant bacteria and/or resistance genes could be acquired by humans through the food chain.201121852287
1083100.9997Molecular Characterization of Colistin-Resistant Escherichia coli Isolated from Chickens: First Report from Nepal. Dissemination of mcr-1 encoding colistin resistance in Gram-negative bacteria has created critical situation in poultry, livestock farming, and public health. In Nepal, for the first time, we initiated surveillance of colistin-resistant Escherichia coli in broilers from seven different chicken farms. A total of 324 cloacal swabs were collected and 118 E. coli were isolated, of which 27 (22.8%) were colistin resistance all harboring mcr-1 gene, but lacking ISApI1. Colistin-resistant isolates were characterized by antibiotic susceptibility testing, detecting antibiotic resistance genes, phylogenetic analysis, and plasmid replicon typing. These isolates belonged to the phylo-group A (70.37%) and phylo-group D (29.63%). In addition, most isolates (>80%) were resistant to ciprofloxacin, tetracycline, and sulfamethoxazole-trimethoprim. As much as 3 of the 27 mcr-1 encoding isolates were confirmed as extended-spectrum β-lactamase (ESBL) producer, all 3 isolates carrying bla(CTX-M) gene. We performed the conjugation experiment to check transferability of mcr-1, tet, and bla(CTX-M) genes, and only two donors were found to have transferred resistance to ticarcillin. The transfer of colistin and tetracycline resistance was not detected, which suggests the chromosomal location of mcr-1 and tet genes. The prevalence of Inc K/B and Inc I1 was 96.3% and 81.48%, respectively. This study shows the co-existence of mcr-1 with tet, sul, qnr, dfr, and bla(CTX-M) genes and dissemination of these resistant isolates in Nepalese chicken farms, which may pose huge threat to the livestock, especially chickens, and public health in Nepal.201930874473
1152110.9997Gut 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.202235321080
1189120.9997Detection of the carbapenemase gene bla(VIM-5) in members of the Pseudomonas putida group isolated from polluted Nigerian wetlands. There are increasing concerns about possible dissemination of clinically relevant antibiotic resistance genes, including genes encoding for carbapenemases in the environment. However, little is known about environmental distribution of antibiotic resistance in Africa. In this study, four polluted urban wetlands in Nigeria were investigated as potential reservoirs of carbapenem-resistant bacteria (CRB). CRB were isolated from the wetlands, characterized by Blue-Carba test, MIC determinations and whole genome sequencing (WGS). Nine of 65 bacterial isolates identified as members of the Pseudomonas putida group (P. plecoglossicida and P. guariconensis, respectively) harboured the metallo-beta-lactamase gene bla(VIM-5). WGS revealed the bla(VIM-5) in three novel Tn402-like class 1 integron structures containing the cassette arrays aadB|bla(VIM-5)|bla(PSE-1), aadB|bla(VIM-5)|aadB|bla(PSE-1), and bla(VIM-5)|aadB|tnpA|bla(PSE-1)|smr2|tnpA, respectively. Strains carrying the aadB|bla(VIM-5)|bla(PSE-1) cassette also carried an identical integron without bla(VIM-5). In addition(,) the strains harboured another Tn402-like class 1 integron carrying bcr2, several multidrug resistance efflux pumps, and at least one of ampC, aph(3")-lb, aph(6)-ld, tetB, tetC, tetG, floR, and macAB. This is the first report of a carbapenemase gene in bacteria from environmental sources in Nigeria and the first report of bla(VIM-5) in environmental bacteria isolates. This result underscores the role of the Nigerian environment as reservoir of bacteria carrying clinically relevant antibiotic resistance genes.201830310126
1010130.9997Prevalence of Antibiotic Resistance and Virulence Genes in Escherichia coli Carried by Migratory Birds on the Inner Mongolia Plateau of Northern China from 2018 to 2023. (1) Background: Antibiotic resistance in bacteria is an urgent global threat to public health. Migratory birds can acquire antibiotic-resistant and pathogenic bacteria from the environment or through contact with each other and spread them over long distances. The objectives of this study were to explore the relationship between migratory birds and the transmission of drug-resistant pathogenic Escherichia coli. (2) Methods: Faeces and swab samples from migratory birds were collected for isolating E. coli on the Inner Mongolia Plateau of northern China from 2018 to 2023. The resistant phenotypes and spectra of isolates were determined using a BD Phoenix 100 System. Conjugation assays were performed on extended-spectrum β-lactamase (ESBL)-producing strains, and the genomes of multidrug-resistant (MDR) and ESBL-producing isolates were sequenced and analysed. (3) Results: Overall, 179 isolates were antibiotic-resistant, with 49.7% MDR and 14.0% ESBL. Plasmids were successfully transferred from 32% of ESBL-producing strains. Genome sequencing analysis of 91 MDR E. coli strains identified 57 acquired resistance genes of 13 classes, and extraintestinal pathogenic E. coli and avian pathogenic E. coli accounted for 26.4% and 9.9%, respectively. There were 52 serotypes and 54 sequence types (STs), including ST48 (4.4%), ST69 (4.4%), ST131 (2.2%) and ST10 (2.2%). The international high-risk clonal strains ST131 and ST10 primarily carried bla(CTX-M-27) and bla(TEM-176). (4) Conclusions: There is a high prevalence of multidrug-resistant virulent E. coli in migratory birds on the Inner Mongolian Plateau. This indicates a risk of intercontinental transmission from migratory birds to livestock and humans.202438930458
2022140.9997Analysis 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
1102150.9997Characterization of multidrug-resistant Gram-negative bacilli isolated from hospitals effluents: first report of a bla(OXA-48)-like in Klebsiella oxytoca, Algeria. The antibiotic susceptibility profile and antimicrobial resistance determinants were characterized on Gram-negative bacilli (GNB) isolated from Algerian hospital effluents. Among the 94 isolates, Enterobacteriaceae was the predominant family, with Escherichia coli and Klebsiella pneumoniae being the most isolated species. In non-Enterobacteriaceae, Acinetobacter and Aeromonas were the predominant species followed by Pseudomonas, Comamonas, Pasteurella, and Shewanella spp. The majority of the isolates were multidrug-resistant (MDR) and carried different antimicrobial resistance genes including bla(CTX-M), bla(TEM), bla(SHV), bla(OXA-48)-like, bla(OXA-23), bla(OXA-51), qnrB, qnrS, tet(A), tet(B), tet(C), dfrA1, aac(3)-IIc (aacC2), aac(6')-1b, sul1, and sul2. The qacEΔ1-sul1 and intI2 signatures of class 1 and class 2 integrons, respectively, were also detected. Microarray hybridization on MDR E. coli revealed additional resistance genes (aadA1 and aph3strA, tet30, mphA, dfrA12, bla(cmy2), bla(ROB1), and cmlA1) and classified the tested strains as commensals, thus highlighting the potential role of humans in antibiotic resistance dissemination. This study is the first report of bla(OXA-48)-like in Klebsiella oxytoca in Algeria and bla(OXA-23) in A. baumannii in Algerian hospital effluents. The presence of these bacteria and resistance genes in hospital effluents represents a serious public health concern since they can be disseminated in the environment and can colonize other hosts.201930637660
1188160.9997High 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
1080170.9997Zoo animals as reservoirs of gram-negative bacteria harboring integrons and antimicrobial resistance genes. A total of 232 isolates of gram-negative bacteria were recovered from mammals, reptiles, and birds housed at Asa Zoological Park, Hiroshima prefecture, Japan. Forty-nine isolates (21.1%) showed multidrug resistance phenotypes and harbored at least one antimicrobial resistance gene. PCR and DNA sequencing identified class 1 and class 2 integrons and many beta-lactamase-encoding genes, in addition to a novel AmpC beta-lactamase gene, bla(CMY-26). Furthermore, the plasmid-mediated quinolone resistance genes qnr and aac(6')-Ib-cr were also identified.200717720829
902180.9997Occurrence of IMP-8, IMP-10, and IMP-13 metallo-β-lactamases located on class 1 integrons and other extended-spectrum β-lactamases in bacterial isolates from Tunisian rivers. BACKGROUND: Antibiotic-resistant bacteria have been surveyed widely in water bodies, but few studies have determined the diversity of antibiotic-resistant bacteria in river waters. This study was undertaken to investigate the origin of resistance among polluted river bacterial isolates in Tunisia. METHODS: In this study 128 isolates resistant to β-lactam antibiotics were obtained from 2 polluted rivers in the north of Tunisia. Isolates were identified using Phoenix phenotyping criteria. The occurrence of bla(TEM), bla(SHV), bla(CTX-M), bla(CMY), bla(VIM), and bla(IMP) was studied by polymerase chain reaction (PCR) amplification and sequencing, and the genetic relatedness of the 16 IMP-producing Klebsiella pneumoniae isolates was analyzed by comparison of XbaI pulsed-field gel electrophoresis (PFGE) profiles. RESULTS: Using Phoenix phenotyping criteria, diverse genera of bacteria were identified with different rates of prevalence and with different minimum inhibitory concentrations against different antibiotics. The occurrence of bla(TEM), bla(SHV), bla(CTXM), bla(CMY), bla(VIM), and bla(IMP) genes was confirmed. The DNA sequences upstream and downstream of bla(IMP) genes were determined, revealing that all IMP-encoding genes constituted the first cassette of class 1 integrons, followed by aacA gene cassettes encoding aminoglycoside resistance. Comparison of PFGE profiles showed that only 2 of the isolates were clonal, the other 14 displaying unique profiles. The bla(CTX-M) gene was the most dominant of the extended-spectrum β-lactamase (ESBL) genes, while the bla(TEM) gene was the second-most dominant. CONCLUSION: The discovery of highly diverse ESBL-producing bacteria and metallo-β-lactamases, particularly bla(IMP), in polluted river water raises alarms with regard to the potential dissemination of antibiotic-resistant bacteria in communities through river environments.201322992193
899190.9997Whole-Genome Sequencing Snapshot of Clinically Relevant Carbapenem-Resistant Gram-Negative Bacteria from Wastewater in Serbia. Wastewater (WW) is considered a source of antibiotic-resistant bacteria with clinical relevance and may, thus, be important for their dissemination into the environment, especially in countries with poor WW treatment. To obtain an overview of the occurrence and characteristics of carbapenem-resistant Gram-negative bacteria (CR-GNB) in WW of Belgrade, we investigated samples from the four main sewer outlets prior to effluent into international rivers, the Sava and the Danube. Thirty-four CR-GNB isolates were selected for antimicrobial susceptibility testing (AST) and whole-genome sequencing (WGS). AST revealed that all isolates were multidrug-resistant. WGS showed that they belonged to eight different species and 25 different sequence types (STs), seven of which were new. ST101 K. pneumoniae (bla(CTX-M-15)/bla(OXA-48)) with novel plasmid p101_srb was the most frequent isolate, detected at nearly all the sampling sites. The most frequent resistance genes to aminoglycosides, quinolones, trimethroprim-sulfamethoxazole, tetracycline and fosfomycin were aac(6')-Ib-cr (55.9%), oqxA (32.3%), dfrA14 (47.1%), sul1 (52.9%), tet(A) (23.5%) and fosA (50%), respectively. Acquired resistance to colistin via chromosomal-mediated mechanisms was detected in K. pneumoniae (mutations in mgrB and basRS) and P. aeruginosa (mutation in basRS), while a plasmid-mediated mechanism was confirmed in the E. cloacae complex (mcr-9.1 gene). The highest number of virulence genes (>300) was recorded in P. aeruginosa isolates. Further research is needed to systematically track the occurrence and distribution of these bacteria so as to mitigate their threat.202336830261