# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 1733 | 0 | 1.0000 | Dissemination and Comparison of Genetic Determinants of mcr-Mediated Colistin Resistance in Enterobacteriaceae via Retailed Raw Meat Products. The global food chain may significantly promote the dissemination of bacteria resistant to antibiotics around the world. This study was aimed at determining the prevalence and genetic characteristics of Enterobacteriaceae with mcr-mediated colistin (CT) resistance in retail meat of different origins. Bacteria of the Enterobacteriaceae family carrying the mcr-1 gene were detected in 21% (18/86) of the examined samples, especially in turkey meat and liver originating from EU and non-EU countries (19%) and in rabbit meat imported from China (2%). The examined samples of the meat and liver of chicken and other poultry and of pork and beef were negative for the presence of bacteria carrying the mcr-1 to mcr-5 genes. A huge number of isolates belonging to Escherchia coli (n = 54), Klebsiella pneumoniae (n = 6), and Citrobacter braakii (n = 1) carrying the mcr-1 gene were obtained. Despite the high heterogeneity of the tested isolates, the mcr-1 gene was localized on only three types of plasmids (IncX4, IncHI2, and IncI2). The most frequent type of plasmid was IncX4, which carried the mcr-1 gene in 77% of E. coli and K. pneumoniae isolates from turkey meat and liver samples from the Czechia, Germany, Poland, and Brazil. Our findings indicate highly probable interspecies transfer of IncX4 and IncI2 plasmids within one meat sample. The co-resistance of plasmid-mediated CT resistance encoded by the mcr-1 and ESBL genes was detected in 18% of the isolates. Another noteworthy finding was the fosA3 gene coding for fosfomycin resistance in a multidrug-resistant isolate of E. coli from rabbit meat imported from China. The observed high level of Enterobacteriaceae with plasmids carrying the mcr-1 gene in retail meat reflects the need for Europe-wide monitoring of mcr-mediated CT resistance throughout the whole food chain. | 2019 | 31921017 |
| 1732 | 1 | 0.9999 | High Carriage Rate of the Multiple Resistant Plasmids Harboring Quinolone Resistance Genes in Enterobacter spp. Isolated from Healthy Individuals. Antimicrobial-resistant bacteria causing intractable and even fatal infections are a major health concern. Resistant bacteria residing in the intestinal tract of healthy individuals present a silent threat because of frequent transmission via conjugation and transposition. Plasmids harboring quinolone resistance genes are increasingly detected in clinical isolates worldwide. Here, we investigated the molecular epidemiology of plasmid-mediated quinolone resistance (PMQR) in Gram-negative bacteria from healthy service trade workers. From 157 rectal swab samples, 125 ciprofloxacin-resistant strains, including 112 Escherichia coli, 10 Klebsiella pneumoniae, two Proteus mirabilis, and one Citrobacter braakii, were isolated. Multiplex PCR screening identified 39 strains harboring the PMQR genes (including 17 qnr,19 aac(6')-Ib-cr, and 22 oqxA/oqxB). The genome and plasmid sequences of 39 and 31 strains, respectively, were obtained by short- and long-read sequencing. PMQR genes mainly resided in the IncFIB, IncFII, and IncR plasmids, and coexisted with 3-11 other resistance genes. The high PMQR gene carriage rate among Gram-negative bacteria isolated from healthy individuals suggests the high-frequency transmission of these genes via plasmids, along with other resistance genes. Thus, healthy individuals may spread antibiotic-resistant bacterial, highlighting the need for improved monitoring and control of the spread of antibiotic-resistant bacteria and genes in healthy individuals. | 2021 | 35052892 |
| 884 | 2 | 0.9999 | Fecal carriage and molecular epidemiology of mcr-1-harboring Escherichia coli from children in southern China. BACKGROUND: The increase of multidrug-resistant Enterobacteriaceae bacteria has led to the reintroduction of colistin for clinical treatments, and colistin has become a last resort for infections caused by multidrug-resistant bacteria. Enterobacteriaceae bacteria carrying the mcr-1 gene are majorly related to colistin resistance, which may be the main reason for the continued increase in the colistin resistance rate of Enterobacteriaceae. The study aimed to investigate the sequence type and prevalence of Escherichia coli (E. coli) harboring the mcr-1 gene in the gut flora of children in southern China. METHODS: Fecal samples (n = 2632) of children from three medical centers in Guangzhou were cultured for E. coli. The mcr-1-harboring isolates were screened via polymerase chain reaction (PCR). The colistin resistance transfer frequency was studied by conjugation experiments. DNA sequencing data of seven housekeeping genes were used for multi-locus sequence typing analysis (MLST). RESULTS: PCR indicated that 21 of the 2632 E. coli (0.80%) isolates were positive for mcr-1; these strains were resistant to colistin. Conjugation experiments indicated that 18 mcr-1-harboring isolates could transfer colistin resistance phenotypes to E. coli J53. MLST analysis revealed that the 21 isolates were divided into 18 sequence types (STs); E. coli ST69 was the most common (14.3%), followed by E. coli ST58 (9.5%). CONCLUSION: These results demonstrate the colonization dynamics and molecular epidemiology of E. coli harboring mcr-1 in the gut flora of children in southern China. The mcr-1 gene can be horizontally transmitted within species; hence, it is necessary to monitor bacteria that harbor mcr-1 in children. | 2023 | 37196369 |
| 1734 | 3 | 0.9999 | Identification and characterization of plasmid-mediated quinolone resistance determinants in Enterobacteriaceae isolated from healthy poultry in Brazil. The expression of plasmid-mediated quinolone resistance (PMQR) genes confers low-level quinolone and fluoroquinolones resistance alone. However, the association to chromosomal resistance mechanisms determines an expressively higher resistance in Enterobacteriaceae. These mechanisms are horizontally disseminated within plasmids and have contributed to the emergence of bacteria with reduced susceptibility or resistant to therapies worldwide. The epidemiological characterization of PMQR dissemination is highly relevant in the scientific and medical context, to investigate the dissemination within enterobacteria, from different populations, including humans and food-producing animals. In the present study, 200 Enterobacteriaceae isolates were harvested from poultry with cloacal swabs and identified as Escherichia coli (90.5%), Escherichia fergusonii (5.5%), Klebsiella oxytoca (2.5%) and Klebsiella pneumoniae (1.5%). Among isolates evaluated, 46 (23%) harboured PMQR genes including qnrB (43/200), qnrS (2/200) and aac(6')-Ib-cr (1/200). All isolates carrying PMQR genes showed multidrug-resistance phenotype. The 36 E. coli isolates showed 18 different PFGE types. All E. fergusonii isolates showed the same PFGE type. The two Klebsiella oxytoca belonged to two different PFGE types. The phylogenetic groups A, B1, and D were found among the E. coli harboring PMQR genes. Based on the phylogenetic analysis and PFGE, the population structure of E. coli isolates was diverse, even within the same farm. All isolates carrying qnrB and qnrS genes also harboured ColE-like plasmids. The Southern blot hybridization using the S1-PFGE revealed that the qnrB genes were located on low molecular weight plasmids, smaller than 10Kb. Resistance plasmids were sequenced and showed 100% identity with plasmid pPAB19-3. The association of PMQR genes with mobile genetic elements, such as transferable plasmids, favours the selection and dissemination of (fluoro) quinolones resistant bacteria among food-producing animals, and may play an important role in the current increased prevalence of resistant bacteria in different environments reported worldwide. | 2018 | 29427764 |
| 1731 | 4 | 0.9999 | Prevalence of Colistin Resistance in Escherichia coli in Eastern Turkey and Genomic Characterization of an mcr-1 Positive Strain from Retail Chicken Meat. Colistin is one of the most effective antibiotics against multidrug resistant Gram-negative bacteria. However, the recent emergence of plasmid-borne mobilized colistin resistance (mcr) genes is considered a serious antimicrobial resistance challenge worldwide. In this study, we report detection of an mcr-1 carrying Escherichia coli isolate (named ATAVET mcr-1 Turkey) from retail raw chicken meat in Turkey. Of the 11 (from 500 total tested) phenotypically colistin-resistant isolates, 1 was shown to carry the mcr-1 gene by PCR. Whole-genome sequencing indicated that mcr-1 was located on a ∼13 kb-long contig that was almost identical to the corresponding part in pZJ1635, an IncI2 plasmid encoding mcr-1 in the same genetic context in another E. coli strain. In addition, ATAVET mcr-1 Turkey harbored bla(CTX-M-8), qnrB19, mdf(A), tet(A), sul2, aph(3″)-Ib, aph(6)-Id, and floR resistance genes. Phylogenetic analysis based on whole genome and multilocus sequence typing indicated that ATAVET mcr-1 Turkey was more closely related to mcr-1 carrying E. coli isolates from food and human clinical samples previously reported from different parts of the world than to those from Turkey. These findings further emphasize the worldwide emergence and spread of mcr meditated colistin resistance in bacteria with zoonotic potential within animals and the food chain. | 2021 | 32721263 |
| 1084 | 5 | 0.9999 | The emergence of colistin-resistant Escherichia coli in chicken meats in Nepal. The emergence and dissemination of colistin resistance among Gram-negative bacteria is a global problem. We initiated a surveillance of colistin-resistant and -susceptible Escherichia coli in raw meats from chicken in Nepal. A total of 180 meat samples were collected; from these, 60 E. coli strains were isolated (33.33%), of which 16 (26.66%) were colistin-resistant and harboured the mcr-1 gene. All isolates were characterised by antibiotic susceptibility testing, the presence of antibiotic resistance genes, phylogenetic analysis and plasmid replicon typing. Most of the colistin-resistant E. coli had the antibiotic resistant pattern CIP/CN/SXT/TE (43.75%). Coexistence of tet, qnr, sul and dfr genes was detected in both colistin-resistant and -susceptible E. coli. Most colistin-resistant E. coli strains belonged to phylogroup C, whereas 10% of isolates belonged to phylogroup D. Inc FIB was the dominant plasmid Inc type in the isolates. Dissemination of antibiotic-resistant E. coli in raw meats is a public health concern in Nepal and requires further investigation to ascertain the sources of contamination. | 2019 | 31755930 |
| 1730 | 6 | 0.9999 | Molecular Epidemiology of mcr-Encoded Colistin Resistance in Enterobacteriaceae From Food-Producing Animals in Italy Revealed Through the EU Harmonized Antimicrobial Resistance Monitoring. Colistin resistance by mobilisable mcr genes has been described in bacteria of food-animal origin worldwide, which has raised public health concerns about its potential foodborne transmission to human pathogenic bacteria. Here we provide baseline information on the molecular epidemiology of colistin-resistant, mcr-positive Escherichia coli and Salmonella isolates in food-producing animals in Italy in 2014-2015. A total 678, 861 and 236 indicator E. coli, Extended Spectrum Beta-Lactamase (ESBL)/AmpC-producing E. coli, and Salmonella isolates, respectively, were tested for colistin susceptibility. These isolates were collected according to the EU harmonized antimicrobial resistance monitoring program and are representative of at least 90 and 80% of the Italian poultry (broiler chickens and turkeys) and livestock (pigs and bovines < 12 months) production, respectively. Whole genome sequencing by Illumina technology and bioinformatics (Center for Genomic Epidemiology pipeline) were used to type 42 mcr-positive isolates by PCR. Colistin resistance was mainly observed in the ESBL/AmpC E. coli population, and was present in 25.9, 5.3, 6.5, and 3.9% of such isolates in turkeys, broilers, pigs, and bovines, respectively. Most colistin-resistant isolates (141/161, 87.5%) harbored genes of the mcr-1 group. mcr-1 was also detected in a small proportion of Salmonella isolates (3/146, 2.0%) in turkeys. Additional mcr types were mcr-3 in four ESBL-producing E. coli from bovines, and two mcr-4 in ESBL (n = 1) and indicator E. coli (n = 1) from pigs and bovines. We describe notable diversity of mcr variants with predominance of mcr-1.1 and mcr-1.2 on conjugative IncX4 plasmids in E. coli and in Salmonella serovars Typhimurium, Newport, Blockley from turkey. A new variant, mcr-1.13 was detected in the chromosome in E. coli in turkey and pig isolates. Additionally, we describe mcr-3.2 and mcr-4.3 in E. coli from bovines, and mcr-4.2 in E. coli from pigs. These findings elucidate the epidemiology of colistin resistance in food-producing animals in Italy along with its genetic background, and highlight the likelihood of mcr horizontal transfer between commensal bacteria and major food-borne pathogens (Salmonella) within the same type of productions. Thorough action and strategies are needed in order to mitigate the risk of mcr transfer to humans, in a "One Health" perspective. | 2018 | 29951045 |
| 1613 | 7 | 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 |
| 1735 | 8 | 0.9999 | Multiple transmissible genes encoding fluoroquinolone and third-generation cephalosporin resistance co-located in non-typhoidal Salmonella isolated from food-producing animals in China. The aim of this study was to identify genes conferring resistance to fluoroquinolones and extended-spectrum β-lactams in non-typhoidal Salmonella (NTS) from food-producing animals in China. In total, 31 non-duplicate NTS were obtained from food-producing animals that were sick. Isolates were identified and serotyped and the genetic relatedness of the isolates was determined by pulsed-field gel electrophoresis of XbaI-digested chromosomal DNA. Antimicrobial susceptibility was determined using Clinical and Laboratory Standards Institute methodology. The presence of extended-spectrum β-lactamase (ESBL) and fluoroquinolone resistance genes was established by PCR and sequencing. Genes encoded on transmissible elements were identified by conjugation and transformation. Plasmids were typed by PCR-based replicon typing. The occurrence and diversity of numerous different transmissible genes conferring fluoroquinolone resistance [qnrA, qnrD, oqxA and aac(6')-Ib-cr] and ESBLs (CTX-M-27 and CTX-M-14), and which co-resided in different isolates and serovars of Salmonella, were much higher than in European countries. Furthermore, different plasmids encoded fluoroquinolone resistance (ca. 6 kb) and β-lactam resistance (ca. 63 kb) and these co-resided in isolates with mutations in topoisomerase genes (gyrA and parC) giving very resistant Salmonella. The presence of multidrug-resistant bacteria in food-producing animals in countries that export foodstuffs suggests that global transfer of antibiotic resistances from country to country on food is possible. | 2014 | 24581597 |
| 1629 | 9 | 0.9999 | Molecular detection of colistin resistance genes (mcr-1 to mcr-5) in human vaginal swabs. OBJECTIVE: Colistin resistance has emerged worldwide and has been threatening the efficacy of one of the last-resort antimicrobials used for treatment of multidrug resistant Gram-negative bacteria. While five colistin resistance genes (mcr-1, mcr-2, mcr-3, mcr-4 and mcr-5) have been described, few data are available on the prevalence of mcr-genes other than mcr-1 in human samples. RESULTS: In this study, the presence of five currently described colistin resistance genes (mcr 1-5) in vaginal swabs of women undergoing infertility evaluation was reported. Most samples were found to be positive for the mcr-4 (12.7%), followed by two for the mcr-2 (1.5%), two for the mcr-3 (1.5%), one for the mcr-1 (0.7%), and one for the mcr-5 (0.7%). Phylogenetic comparison demonstrated identical (mcr-1, mcr-2, mcr-3, mcr-5) or similar (mcr-4) nucleotide sequences of human samples and those of animal origins from the same city, suggesting the potential transmission of mcr genes from animals to humans. This is the first detection of mcr-2, mcr-4 and mcr-5 genes in human samples, and warrants further research to determine the spread of the mcr genes and elucidate the full epidemiology of colistin resistance genes in humans. | 2018 | 29463301 |
| 1143 | 10 | 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 |
| 1614 | 11 | 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 |
| 1729 | 12 | 0.9999 | Plasmid-Borne and Chromosomal ESBL/AmpC Genes in Escherichia coli and Klebsiella pneumoniae in Global Food Products. Plasmid-mediated extended-spectrum beta-lactamase (ESBL), AmpC, and carbapenemase producing Enterobacteriaceae, in particular Escherichia coli and Klebsiella pneumoniae, with potential zoonotic transmission routes, are one of the greatest threats to global health. The aim of this study was to investigate global food products as potential vehicles for ESBL/AmpC-producing bacteria and identify plasmids harboring resistance genes. We sampled 200 food products purchased from Finland capital region during fall 2018. Products originated from 35 countries from six continents and represented four food categories: vegetables (n = 60), fruits and berries (n = 50), meat (n = 60), and seafood (n = 30). Additionally, subsamples (n = 40) were taken from broiler meat. Samples were screened for ESBL/AmpC-producing Enterobacteriaceae and whole genome sequenced to identify resistance and virulence genes and sequence types (STs). To accurately identify plasmids harboring resistance and virulence genes, a hybrid sequence analysis combining long- and short-read sequencing was employed. Sequences were compared to previously published plasmids to identify potential epidemic plasmid types. Altogether, 14 out of 200 samples were positive for ESBL/AmpC-producing E. coli and/or K. pneumoniae. Positive samples were recovered from meat (18%; 11/60) and vegetables (5%; 3/60) but were not found from seafood or fruit. ESBL/AmpC-producing E. coli and/or K. pneumoniae was found in 90% (36/40) of broiler meat subsamples. Whole genome sequencing of selected isolates (n = 21) revealed a wide collection of STs, plasmid replicons, and genes conferring multidrug resistance. bla (CTX-M-15)-producing K. pneumoniae ST307 was identified in vegetable (n = 1) and meat (n = 1) samples. Successful IncFII plasmid type was recovered from vegetable and both IncFII and IncI1-Iγ types from meat samples. Hybrid sequence analysis also revealed chromosomally located beta-lactamase genes in two of the isolates and indicated similarity of food-derived plasmids to other livestock-associated sources and also to plasmids obtained from human clinical samples from various countries, such as IncI type plasmid harboring bla (TEM-52C) from a human urine sample obtained in the Netherlands which was highly similar to a plasmid obtained from broiler meat in this study. Results indicate certain foods contain bacteria with multidrug resistance and pose a possible risk to public health, emphasizing the importance of surveillance and the need for further studies on epidemiology of epidemic plasmids. | 2021 | 33613476 |
| 1022 | 13 | 0.9998 | Characterization of Beta-lactamases in Faecal Enterobacteriaceae Recovered from Healthy Humans in Spain: Focusing on AmpC Polymorphisms. The intestinal tract is a huge reservoir of Enterobacteriaceae, some of which are opportunist pathogens. Several genera of these bacteria harbour intrinsic antibiotic resistance genes, such as ampC genes in species of Citrobacter, Enterobacter or Escherichia genera. In this work, beta-lactamases and other resistance mechanisms have been characterized in Enterobacteriaceae isolates recovered from healthy human faecal samples, focusing on the ampC beta-lactamase genes. Fifty human faecal samples were obtained, and 70 Enterobacteriaceae bacteria were isolated: 44 Escherichia coli, 4 Citrobacter braakii, 9 Citrobacter freundii, 8 Enterobacter cloacae, 1 Proteus mirabilis, 1 Proteus vulgaris, 1 Klebsiella oxytoca, 1 Serratia sp. and 1 Cronobacter sp. A high percentage of resistance to ampicillin was detected (57%), observing the AmpC phenotype in 22 isolates (31%) and the ESBL phenotype in 3 isolates. AmpC molecular characterization showed high diversity into bla CMY and bla ACT genes from Citrobacter and Enterobacter species, respectively, and the pulsed-field gel electrophoresis (PFGE) analysis demonstrated low clonality among them. The prevalence of people colonized by strains carrying plasmid-mediated ampC genes obtained in this study was 2%. The unique plasmid-mediated bla AmpC identified in this study was the bla CMY-2 gene, detected in an E. coli isolate ascribed to the sequence type ST405 which belonged to phylogenetic group D. The hybridization and conjugation experiments demonstrated that the ISEcp1-bla CMY-2-blc structure was carried by a ~78-kb self-transferable IncK plasmid. This study shows a high polymorphism among beta-lactamase genes in Enterobacteriaceae from healthy people microbiota. Extensive AmpC-carrier studies would provide important information and could allow the anticipation of future global health problems. | 2015 | 25501887 |
| 2981 | 14 | 0.9998 | 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 |
| 1624 | 15 | 0.9998 | Detection of chromosomal and plasmid-mediated mechanisms of colistin resistance in Escherichia coli and Klebsiella pneumoniae from Indian food samples. OBJECTIVES: Numerous previous publications on the detection of bacterial isolates harbouring the mcr-1 gene from animals and humans strongly suggest an underlying route of transmission of colistin resistance via the food chain. The aim of this study was to investigate the presence of colistin-resistant (Col-R) bacteria in Indian food samples and to identify the underlying mechanisms conferring colistin resistance. METHODS: Raw food material, including poultry meat, mutton meat, fish, fruit and vegetables, collected from food outlets in Chennai, India, were processed to identify Col-R bacteria using eosin methylene blue agar supplemented with colistin. Colistin minimum inhibitory concentrations (MICs) were determined by the broth microdilution method. PCR for the mcr-1 and mcr-3 genes was performed on Col-R Escherichia coli and Klebsiella pneumoniae isolates. Mutations in the mgrB gene were analysed in K. pneumoniae isolates. One representative mcr-1-positive E. coli was subjected to whole-genome sequencing. RESULTS: Of 110 food samples tested, 51 (46.4%) were positive for non-intrinsic Col-R Gram-negative bacteria. Three E. coli isolates were found to harbour mcr-1, whereas none were positive for mcr-3. Ten K. pneumoniae isolates had alterations in mgrB, with mutations in four and insertional inactivation in six. CONCLUSION: The presence of Col-R bacteria and the mcr-1 gene in raw food samples further complicates the antimicrobial resistance scenario in India. To the best of our knowledge, this is the first report in the global literature on mgrB mutation and its insertional inactivation conferring Col-R in K. pneumoniae from food samples. | 2019 | 30244040 |
| 1616 | 16 | 0.9998 | Characterization 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. | 2020 | 32083678 |
| 1611 | 17 | 0.9998 | Molecular Typing of Enterobacteriaceae from Pig Holdings in North-Western Germany Reveals Extended- Spectrum and AmpC β-Lactamases Producing but no Carbapenem Resistant Ones. The increase of extended- spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) in humans and in food-producing animals is of public health concern. The latter could contribute to spreading of these bacteria or their resistance genes to humans. Several studies have reported the isolation of third generation cephalosporin resistant bacteria in livestock animals. However, the number of samples and the methodology used differ considerably between studies limiting comparability and prevalence assessment. In the present study, a total of 564 manure and dust samples were collected from 47 pig farms in Northern Germany and analysed to determine the prevalence of ESBL-E. Molecular typing and characterization of resistance genes was performed for all ESBL-E isolates. ESBL-E isolates were found in 55.3% of the farms. ESBL-Escherichia coli was found in 18.8% of the samples, ESBL-Klebsiella pneumoniae in 0.35%. The most prevalent ESBL genes among E. coli were CTX-M-1 like (68.9%), CTX-M-15 like (16%) and CTX-M-9 group (14.2%). In 20% of the latter two, also the OXA-1 like gene was found resulting in a combination of genes typical for isolates from humans. Genetic relation was found between isolates not only from the same, but also from different farms, with multilocus sequence type (ST) 10 being predominant among the E. coli isolates. In conclusion, we showed possible spread of ESBL-E between farms and the presence of resistance genes and STs previously shown to be associated with human isolates. Follow-up studies are required to monitor the extent and pathways of ESBL-E transmission between farms, animals and humans. | 2015 | 26225428 |
| 1726 | 18 | 0.9998 | Molecular epidemiology and population genomics of tet(X4), bla(NDM) or mcr-1 positive Escherichia coli from migratory birds in southeast coast of China. The emergence of multidrug-resistant (MDR) bacteria harboring tet(X4), bla(NDM) or mcr-1 posed a serious threat to public health. Wild birds, especially migratory birds, were considered as one of important transmission vectors for antibiotic resistance genes (ARGs) globally, however, few studies were performed on the genomic epidemiology of critical resistance genes among them. Isolates harboring tet(X4), mcr-1 or bla(NDM) from migratory birds were identified and characterized by PCR, antimicrobial susceptibility testing, conjugation assays, whole genome sequencing and bioinformatics analysis. A total of 14 tet(X4)-bearing E. coli, 4 bla(NDM)-bearing E. coli and 23 mcr-1-bearing E. coli isolates were recovered from 1060 fecal samples of migratory birds. All isolates were MDR bacteria and most plasmids carrying tet(X4), bla(NDM) or mcr-1 were conjugative. We first identified an E. coli of migratory bird origin carrying bla(NDM-4), which was located on a conjugative IncHI2 plasmid and embedded on a novel MDR region flanked by IS26 that could generate the circular intermediate. The emergency of E. coli isolates co-harboring mcr-1 and bla(NDM-5) in migratory birds indicated the coexistence of ARGs in migratory birds was a novel threat. This study revealed the prevalence and molecular characteristics of three important ARGs in migratory birds, provided evidence that migratory birds were potential vectors of novel resistance genes and highlighted the monitoring of ARGs in migratory birds should be strengthened to prevent the spread of ARGs in a One Health strategy. | 2022 | 36084501 |
| 1899 | 19 | 0.9998 | Characteristics of plasmids in multi-drug-resistant Enterobacteriaceae isolated during prospective surveillance of a newly opened hospital in Iraq. BACKGROUND: Gram-negative multidrug-resistant (MDR) bacteria are major causes of nosocomial infections, and antibiotic resistance in these organisms is often plasmid mediated. Data are scarce pertaining to molecular mechanisms of antibiotic resistance in resource constrained areas such as Iraq. METHODOLOGY/PRINCIPAL FINDINGS: In this study, all MDR Enterobacteriaceae (n = 38) and randomly selected non-MDR counterparts (n = 41) isolated from patients, healthcare workers and environmental surfaces in a newly opened hospital in Iraq were investigated to characterize plasmids found in these isolates and determine their contribution to antibiotic resistance. Our results demonstrated that MDR E. coli and K. pneumoniae isolates harbored significantly more (≥ 3) plasmids compared to their non-MDR counterparts, which carried ≤ 2 plasmids (p<0.01). Various large plasmids (~52 to 100 kb) from representative isolates were confirmed to contain multiple resistance genes by DNA microarray analysis. Aminoglycoside (acc, aadA, aph, strA/B, and ksgA), β-lactam (bla(TEM1), bla(AMPC), bla(CTX-M-15), bla(OXA-1), bla(VIM-2) and bla(SHV)), sulfamethoxazole/trimethoprim (sul/dfr), tetracycline (tet) and chloramphenicol (cat) resistance genes were detected on these plasmids. Additionally, multiple plasmids carrying multiple antibiotic resistance genes were found in the same host strain. Genetic transfer-associated genes were identified on the plasmids from both MDR and non-MDR isolates. Seven plasmid replicon types (FII, FIA, FIB, B/O, K, I1 and N) were detected in the isolates, while globally disseminated IncA/C and IncHI1 plasmids were not detected in these isolates. CONCLUSIONS/SIGNIFICANCE: This is the first report of the characteristics of the plasmids found in Enterobacteriaceae isolated following the opening of a new hospital in Iraq. The information provided here furthers our understanding of the mechanisms of drug resistance in this specific region and their evolutionary relationship with other parts of world. The large plasmids, carrying resistance genes and transfer-associated genes, may be potential factors for regional dissemination of antibiotic resistance. | 2012 | 22808141 |