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199200.9938Antimicrobial Resistance Genes, Cassettes, and Plasmids Present in Salmonella enterica Associated With United States Food Animals. The ability of antimicrobial resistance (AR) to transfer, on mobile genetic elements (MGEs) between bacteria, can cause the rapid establishment of multidrug resistance (MDR) in bacteria from animals, thus creating a foodborne risk to human health. To investigate MDR and its association with plasmids in Salmonella enterica, whole genome sequence (WGS) analysis was performed on 193 S. enterica isolated from sources associated with United States food animals between 1998 and 2011; 119 were resistant to at least one antibiotic tested. Isolates represented 86 serotypes and variants, as well as diverse phenotypic resistance profiles. A total of 923 AR genes and 212 plasmids were identified among the 193 strains. Every isolate contained at least one AR gene. At least one plasmid was detected in 157 isolates. Genes were identified for resistance to aminoglycosides (n = 472), β-lactams (n = 84), tetracyclines (n = 171), sulfonamides (n = 91), phenicols (n = 42), trimethoprim (n = 8), macrolides (n = 5), fosfomycin (n = 48), and rifampicin (n = 2). Plasmid replicon types detected in the isolates were A/C (n = 32), ColE (n = 76), F (n = 43), HI1 (n = 4), HI2 (n = 20), I1 (n = 62), N (n = 4), Q (n = 7), and X (n = 35). Phenotypic resistance correlated with the AR genes identified in 95.4% of cases. Most AR genes were located on plasmids, with many plasmids harboring multiple AR genes. Six antibiotic resistance cassette structures (ARCs) and one pseudo-cassette were identified. ARCs contained between one and five resistance genes (ARC1: sul2, strAB, tetAR; ARC2: aac3-iid; ARC3: aph, sph; ARC4: cmy-2; ARC5: floR; ARC6: tetB; pseudo-ARC: aadA, aac3-VIa, sul1). These ARCs were present in multiple isolates and on plasmids of multiple replicon types. To determine the current distribution and frequency of these ARCs, the public NCBI database was analyzed, including WGS data on isolates collected by the USDA Food Safety and Inspection Service (FSIS) from 2014 to 2018. ARC1, ARC4, and ARC5 were significantly associated with cattle isolates, while ARC6 was significantly associated with chicken isolates. This study revealed that a diverse group of plasmids, carrying AR genes, are responsible for the phenotypic resistance seen in Salmonella isolated from United States food animals. It was also determined that many plasmids carry similar ARCs.201931057528
126410.9937Characterization of mannitol-fermenting methicillin-resistant staphylococci isolated from pigs in Nigeria. This study was conducted to determine the species distribution, antimicrobial resistance pheno- and genotypes and virulence traits of mannitol-positive methicillin-resistant staphylococci (MRS) isolated from pigs in Nsukka agricultural zone, Nigeria. Twenty mannitol-positive methicillin-resistant coagulase-negative staphylococcal (MRCoNS) strains harboring the mecA gene were detected among the 64 Staphylococcus isolates from 291 pigs. A total of 4 species were identified among the MRCoNS isolates, namely, Staphylococcus sciuri (10 strains), Staphylococcus lentus (6 strains), Staphylococcus cohnii (3 strains) and Staphylococcus haemolyticus (one strain). All MRCoNS isolates were multidrug-resistant. In addition to β-lactams, the strains were resistant to fusidic acid (85%), tetracycline (75%), streptomycin (65%), ciprofloxacin (65%), and trimethoprim/sulphamethoxazole (60%). In addition to the mecA and blaZ genes, other antimicrobial resistance genes detected were tet(K), tet(M), tet(L), erm(B), erm(C), aacA-aphD, aphA3, str, dfrK, dfrG, cat pC221, and cat pC223. Thirteen isolates were found to be ciprofloxacin-resistant, and all harbored a Ser84Leu mutation within the QRDR of the GyrA protein, with 3 isolates showing 2 extra substitutions, Ser98Ile and Arg100Lys (one strain) and Glu88Asp and Asp96Thr (2 strains). A phylogenetic tree of the QRDR nucleotide sequences in the gyrA gene revealed a high nucleotide diversity, with several major clusters not associated with the bacterial species. Our study highlights the possibility of transfer of mecA and other antimicrobial resistance genes from MRCoNS to pathogenic bacteria, which is a serious public health and veterinary concern.201526413075
198920.9936Prevalence and characterization of IncQ1α-mediated multi-drug resistance in Proteus mirabilis Isolated from pigs in Kunming, Yunnan, China. BACKGROUND: Proteus mirabilis is a conditionally pathogenic bacterium that is inherently resistant to polymyxin and tigecycline, largely due to antibiotic resistance genes (ARGs). These ARGs can be horizontally transferred to other bacteria, raising concerns about the Inc plasmid-mediated ARG transmission from Proteus mirabilis, which poses a serious public health threat. This study aims to investigate the presence of Inc plasmid types in pig-derived Proteus mirabilis in Kunming, Yunnan, China. METHODS: Fecal samples were collected from pig farms across six districts of Kunming (Luquan, Jinning, Yiliang, Anning, Songming, and Xundian) from 2022 to 2023. Proteus mirabilis isolates were identified using IDS and 16S rRNA gene sequencing. Then, positive strains underwent antimicrobial susceptibility testing and incompatibility plasmid typing. Multi-drug-resistant isolates with positive incompatibility plasmid genes were selected for whole-genome sequencing. Resistance and Inc group data were then isolated and compared with 126 complete genome sequences from public databases. Whole-genome multi-locus sequence typing, resistance group analysis, genomic island prediction, and plasmid structural gene analysis were performed. RESULTS: A total of 30 isolates were obtained from 230 samples, yielding a prevalence of 13.04%. All isolates exhibited multi-drug resistance, with 100% resistance to cotrimoxazole, erythromycin, penicillin G, chloramphenicol, ampicillin, and streptomycin. Among these, 15 isolates tested positive for the IncQ1α plasmid repC gene. The two most multi-drug-resistant and repC-positive strains, NO. 15 and 21, were sequenced to compare genomic features on Inc groups and ARGs with public data. Genome analysis revealed that the repC gene was primarily associated with IncQ1α, with structural genes from other F-type plasmids (TraV, TraU, TraN, TraL, TraK, TraI, TraH, TraG, TraF, TraE/GumN, and TraA) also present. Strain NO. 15 carried 33 ARGs, and strain NO. 21 carried 38 ARGs, conferring resistance to tetracyclines, fluoroquinolones, aminoglycosides, sulfonamides, peptides, chloramphenicol, cephalosporins, lincomycins, macrolides, and 2-aminopyrimidines. CONCLUSION: The repC gene is primarily associated with IncQ1α, with structural genes from other F-type plasmids. A comparison with 126 public genome datasets confirmed this association.202439850143
126530.9935Coagulase-negative staphylococci (CoNS) isolated from ready-to-eat food of animal origin--phenotypic and genotypic antibiotic resistance. The aim of this work was to study the pheno- and genotypical antimicrobial resistance profile of coagulase negative staphylococci (CoNS) isolated from 146 ready-to-eat food of animal origin (cheeses, cured meats, sausages, smoked fishes). 58 strains were isolated, they were classified as Staphylococcus xylosus (n = 29), Staphylococcus epidermidis (n = 16); Staphylococcus lentus (n = 7); Staphylococcus saprophyticus (n = 4); Staphylococcus hyicus (n = 1) and Staphylococcus simulans (n = 1) by phenotypic and genotypic methods. Isolates were tested for resistance to erythromycin, clindamycin, gentamicin, cefoxitin, norfloxacin, ciprofloxacin, tetracycline, tigecycline, rifampicin, nitrofurantoin, linezolid, trimetoprim, sulphamethoxazole/trimethoprim, chloramphenicol, quinupristin/dalfopristin by the disk diffusion method. PCR was used for the detection of antibiotic resistance genes encoding: methicillin resistance--mecA; macrolide resistance--erm(A), erm(B), erm(C), mrs(A/B); efflux proteins tet(K) and tet(L) and ribosomal protection proteins tet(M). For all the tet(M)-positive isolates the presence of conjugative transposons of the Tn916-Tn1545 family was determined. Most of the isolates were resistant to cefoxitin (41.3%) followed by clindamycin (36.2%), tigecycline (24.1%), rifampicin (17.2%) and erythromycin (13.8%). 32.2% staphylococcal isolates were multidrug resistant (MDR). All methicillin resistant staphylococci harboured mecA gene. Isolates, phenotypic resistant to tetracycline, harboured at least one tetracycline resistance determinant on which tet(M) was most frequent. All of the isolates positive for tet(M) genes were positive for the Tn916-Tn1545 -like integrase family gene. In the erythromycin-resistant isolates, the macrolide resistance genes erm(C) or msr(A/B) were present. Although coagulase-negative staphylococci are not classical food poisoning bacteria, its presence in food could be of public health significance due to the possible spread of antibiotic resistance.201525475289
199340.9935Co-occurrence of antibiotic and disinfectant resistance genes in extensively drug-resistant Escherichia coli isolated from broilers in Ilorin, North Central Nigeria. OBJECTIVES: The occurrence of multidrug-resistant (MDR) bacteria in poultry poses the public health threat of zoonotic transmission to humans. Hence, this study assessed the occurrence of drug-resistant Escherichia coli in broilers in the largest live bird market in Kwara State, Nigeria in December 2020. METHODS: Presumptive E. coli isolates were isolated using the European Union Reference Laboratory guideline of 2017 and confirmed via matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS). Broth microdilution was performed on confirmed E. coli isolates to determine the minimum inhibitory concentration. Five extensively drug-resistant (XDR) isolates were selected for Illumina whole genome sequencing to predict the resistome, phylotype, sequence type, serotype, and diversity of mobile genetic elements in these isolates. RESULTS: Of the 181 broiler caecal samples, 73 E. coli isolates were obtained, of which 67 (82.0%) and 37 (50.6%) were determined as MDR (resistant to at least three classes of antibiotics) and XDR (resistant to at least five classes of antibiotics), respectively. Whole genome sequencing revealed diverse sequence types, phylogroups, and serotypes (ST165/B1 - O80:H19, ST115/A - Unknown: H7, ST901/B1 - O109:H4, ST4087/F - O117:H42, and ST8324/A - O127:H42). The XDR E. coli isolates encoded resistance to fluoroquinolones, fosfomycin, sulfamethoxazole, ampicillin and cephalosporins, trimethoprim, aminoglycosides, chloramphenicol, tetracycline, and macrolides. Mutations in the gyrA gene conferring resistance to fluoroquinolones were also detected. There was a positive correlation between phenotypic resistance patterns and the antibiotic resistance genes that were detected in the sequenced isolates. The XDR isolates also harbored two disinfectant resistance genes (qacE and sitABCD) that conferred resistance to hydrogen peroxide and quaternary ammonium compounds, respectively. The genome of the XDR isolates harbored several mobile genetic elements and virulence-associated genes, which were conserved in all sequenced XDR isolates. CONCLUSIONS: This is the first report of co-carriage of antibiotic resistance genes and disinfectant resistance genes in E. coli isolated from broilers in Ilorin, Nigeria. Our findings suggest that poultry are potential carriers of clonally diverse, pathogenic, MDR/XDR E. coli, which may have detrimental zoonotic potentials on human health.202236375754
240450.9934Prevalence of the Antibiotic Resistance Genes in Coagulase-Positive-and Negative-Staphylococcus in Chicken Meat Retailed to Consumers. The use of antibiotics in farm management (growing crops and raising animals) has become a major area of concern. Its implications is the consequent emergence of antibiotic resistant bacteria (ARB) and accordingly their access into the human food chain with passage of antibiotic resistance genes (ARG) to the normal human intestinal microbiota and hence to other pathogenic bacteria causative human disease. Therefore, we pursued in this study to unravel the frequency and the quinolone resistance determining region, mecA and cfr genes of methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), methicillin-resistant coagulase-negative staphylococci (MRCNS) and methicillin-susceptible coagulase-negative staphylococci (MSCNS) isolated from the retail trade of ready-to-eat raw chicken meat samples collected during 1 year and sold across the Great Cairo area. The 50 Staphylococcus isolated from retail raw chicken meat were analyzed for their antibiotic resistance phenotypic profile on 12 antibiotics (penicillin, oxacillin, methicillin, ampicillin-sulbactam, erythromycin, tetracycline, clindamycin, gentamicin, ciprofloxacin, chloramphenicol, sulfamethoxazole-trimethoprim, and vancomycin) and their endorsement of the quinolone resistance determining region, mecA and cfr genes. The isolation results revealed 50 isolates, CPS (14) and CNS (36), representing ten species (S. aureus, S. hyicus, S. epidermedius, S. lugdunensis, S. haemolyticus, S. hominus, S. schleiferi, S. cohnii, S. intermedius, and S. lentus). Twenty seven isolates were methicillin-resistant. Out of the characterized 50 staphylococcal isolates, three were MRSA but only 2/3 carried the mecA gene. The ARG that bestows resistance to quinolones, β-lactams, macrolides, lincosamides, and streptogramin B [MLS((B))] in MRSA and MR-CNS were perceived. According to the available literature, the present investigation was a unique endeavor into the identification of the quinolone-resistance-determining-regions, the identification of MRSA and MR-CNS from retail chicken meat in Egypt. In addition, these isolates might indicate the promulgation of methicillin, oxacillin and vancomycin resistance in the community and imply food safety hazards.201627920760
132660.9931Antimicrobial resistance and genetic diversity of Enterococcus faecalis from yolk sac infections in broiler chicks. Despite restrictions on the use of antibiotics in poultry, the percentage of multidrug resistant bacteria, isolated from both adult birds and chicks, remains high. These bacteria can spread between countries via hatching eggs or chicks. Antibiotic resistant bacteria can also pose a threat to hatchery and farm workers or to consumers of poultry. The aim of the study was to perform a phenotypic and genotypic analysis of the drug resistance of E. faecalis isolates from yolk sac infections in broiler chicks from Poland and the Netherlands and to determine their genetic diversity. The tests revealed resistance to antibiotics from category D, that is, tetracycline (69.7%); category C - lincomycin (98.7%), erythromycin (51.3%), aminoglycosides (high-level streptomycin and kanamycin resistance - 10.5% and 3.95%, respectively), and chloramphenicol (7.9%); and category B - ciprofloxacin (25% with resistance or intermediate resistance). No resistance to penicillin, ampicillin, high-level gentamicin, tigecycline, or linezolid was noted. Various combinations of the erm(B), tet(M), tet(L), tet(O), ant(6)-Ia, aph(3')-IIIa, ant(4')-Ia, cat, and msr(A/B) genes were detected in all isolates (irrespective of the drug-resistance phenotype). Among isolates that carried the tet(M) and/or the tet(L) gene, 28% also had the Int-Tn gene, in contrast with isolates possessing tet(O). There were 28 sequence types and 43 PFGE restriction patterns. About 60% of isolates were of sequences types ST59, ST16, ST116, ST282, ST36, and ST82. Nine new sequence types were shown (ST836-ST844). In conclusion, broiler chicks can be a source of drug-resistant sequence types of E. faecalis that are potentially hazardous for people and animals. Restrictive programs for antibiotic use in broiler breeding flocks should be developed to decrease drug resistance in day-old chicks and reduce economic losses during rearing.202134695638
237470.9930Phenotypic and genetic antimicrobial resistance of the intestinal microbiota isolated from two alpacas (Vicugna pacos) post mortem. INTRODUCTION: In Poland, alpacas are commonly companion animals and producers of wool. Human-alpaca-environment interactions raise One Health concerns about antimicrobial resistance (AMR). No medications are licensed in Poland for camelids, and so all are prescribed under the cascade; they include β-lactams, cephalosporin, florfenicol, enrofloxacin, marbofloxacin, gentamicin, tetracycline and trimethoprim/sulfamethoxazole. Human and animal bacterial AMR is a matter of global concern. Consequently, the aim of the present study was to determine the prevalence of phenotypic and genotypic AMR among bacteria isolated from alpaca intestines. MATERIAL AND METHODS: Fifty-four strains were identified using matrix-assisted laser desorption/ionisation-time-of-flight mass spectrometry and biochemical methods. Antibacterial susceptibility was assessed by determining minimum inhibitory concentrations and by the Kirby-Bauer method. RESULTS: Citrobacter spp., Enterobacter spp. and Serratia spp. exhibited resistance to β-lactams, first-generation cephalosporins and tetracyclines, with Serratia spp. also resistant to colistin, polymyxin B and florfenicol. Enterococcus spp. were resistant to penicillin G, benzylpenicillin and erythromycin, but not to vancomycin, while Staphylococcus spp. showed resistance to amoxicillin and penicillins, but not to methicillin. Bacillus spp. and Corynebacterium spp. were resistant to some penicillins, tetracyclines and trimethoprim-sulfamethoxazole. Enterobacteriaceae isolates carried resistance genes (aadA, dfrA1, tetA, sul1, sul2, strA/strB and floR); therefore, the tested alpacas' microbiomes harboured AMR determinants. CONCLUSION: Alpacas should be monitored over an extended period to know the risk of transmission of AMR genes from components of their microbiome.202541064399
132480.9930Molecular characterization of antimicrobial resistance in enterococci and Escherichia coli isolates from European wild rabbit (Oryctolagus cuniculus). A total of 44 Escherichia coli and 64 enterococci recovered from 77 intestinal samples of wild European rabbits in Portugal were analyzed for resistance to antimicrobial agents. Resistance in E. coli isolates was observed for ampicillin, tetracycline, sulfamethoxazole/trimethoprim, streptomycin, gentamicin, tobramycin, nalidixic acid, ciprofloxacin and chloramphenicol. None of the E. coli isolates produced extended-spectrum beta-lactamases (ESBLs). The bla(TEM), aadA, aac(3)-II, tet(A) and/or tet(B), and the catA genes were demonstrated in all ampicillin, streptomycin, gentamicin, tetracycline, and chloramphenicol-resistant isolates respectively, and the sul1 and/or sul2 and/or sul3 genes in 4 of 5 sulfamethoxazole/trimethoprim resistant isolates. Of the enterococcal isolates, Enterococcus faecalis was the most prevalent detected species (39 isolates), followed by E. faecium (21 isolates) and E. hirae (4 isolates). More than one-fourth (29.7%) of the isolates were resistant to tetracycline; 20.3% were resistant to erythromycin, 14.1% were resistant to ciprofloxacin and 10.9% were resistant to high-level-kanamycin. Lower level of resistance (<10%) was detected for ampicillin, quinupristin/dalfopristin and high-level-gentamicin, -streptomycin. No vancomycin-resistance was detected in the enterococci isolates. Resistance genes detected included aac(6')-aph(2''), ant(6)-Ia, tet(M) and/or tet(L) in all gentamicin, streptomycin and tetracycline-resistant isolates respectively. The aph(3')-IIIa gene was detected in 6 of 7 kanamycin-resistant isolates, the erm(B) gene in 11 of 13 erythromycin-resistant isolates and the vat(D) gene in the quinupristin/dalfopristin-resistant E. faecium isolate. This survey showed that faecal bacteria such as E. coli and enterococci of wild rabbits could be a reservoir of antimicrobial resistance genes.201020624632
113190.9930Antimicrobial resistance genotypes and phenotypes from multidrug-resistant bacterial wound infection isolates in Cambodia. This study aimed to identify the molecular determinants responsible for antibiotic resistance among human wound isolates in Cambodia. Staphylococcus spp. (n=10) and a variety of Gram-negative isolates (n=21) were taken from a larger collection of wound isolates collected during 2011-2013 and were analysed for the presence of >230 resistance determinants using a broad-spectrum DNA microarray. These isolates were chosen to represent the species most commonly found in wound isolates referred during this time and to include some of the most resistant strains. Resistance determinants detected among the staphylococci included blaZ (90%), mecA (100%), erm(B) (70%), erm(C) (20%), tet(38) (90%), tet(K) (40%), tet(L(p)) (10%), tet(M) (20%), lnu(A)/lin(A) and lnu(B)/lin(B) (10% each), msr(A)/msr(B)/msr(SA) (10%), norA (80%) and dfrA (10%). Eleven different β-lactamase genes were detected among the Gram-negative bacteria, including genes encoding the TEM (48%), CTX-M-1 (48%), CTX-M-9 (5%), SHV (5%) and VEB (10%) families of broad-spectrum and extended-spectrum β-lactamase enzymes, as well as the carbapenemase gene bla(OXA-23). Forty additional genes were also detected in the Gram-negative isolates conferring resistance to aminoglycosides (11 genes), phenicols (5 genes), macrolides [4 genes, including mph(A)/mph(K) (10%)], lincosamides [lnu(F)/lin(F), lnu(G)/lin(G)], tetracycline (4 genes), rifampicin [arr (29%)], quaternary amines [qacEΔ1 (43%)], quinolones [qnrS (14%) and qnrB (5%)], sulfonamides [sul1 (29%), sul2 (38%) and sul3 (10%)], streptothricin (sat2) and trimethoprim (6 genes). The results obtained here provide a snapshot of the broad variety of resistance determinants currently circulating within Cambodia.201527873709
1990100.9930Genomic Analysis of Aeromonas veronii C198, a Novel Mcr-3.41-Harboring Isolate from a Patient with Septicemia in Thailand. The resistance of Gram-negative bacteria to colistin, mediated by plasmid-borne mcr genes, is an emerging public health concern. The complete genome sequence (4.55 Mb) of a clinical isolate of Aeromonas veronii biovar veronii obtained from a patient with septicemia was determined using short-read and long-read platforms. This isolate (C198) was found to harbor a novel mcr-3 gene, designated mcr-3.41. Isolate C198 revealed adjacent mcr-3.41 and mcr-3-like genes. It contained one chromosome and two plasmids, both of which encoded a RepB replication protein. Other antimicrobial resistance genes, including bla(cphA3), bla(OXA-12), tetA, rsmA, and adeF, were also present. Isolate C198 was resistant to amoxicillin-clavulanate, ampicillin-sulbactam and tetracycline, and showed intermediate resistance to trimethoprim-sulfamethoxazole. The isolate was susceptible to piperacillin-tazobactam, carbapenem, third-generation cephalosporins, fluoroquinolones, chloramphenicol, and aminoglycosides. Putative virulence genes in the C198 genome encoded type II, III, and VI secretion systems; type IV Aeromonas pili; and type I fimbria, flagella, hemagglutinin, aerolysin, and hemolysins. Multilocus sequence typing revealed a novel sequence type (ST), ST720 for C198. Phylogenetic analysis of the single nucleotide polymorphisms in C198 demonstrated that the strain was closely related to A. veronii 17ISAe. The present study provides insights into the genomic characteristics of human A. veronii isolates.202033317051
1382110.9929Surveillance of antimicrobial-resistant Escherichia coli in Sheltered dogs in the Kanto Region of Japan. There is a lack of an established antimicrobial resistance (AMR) surveillance system in animal welfare centers. Therefore, the AMR prevalence in shelter dogs is rarely known. Herein, we conducted a survey in animal shelters in Chiba and Kanagawa prefectures, in the Kanto Region, Japan, to ascertain the AMR status of Escherichia coli  (E. coli) prevalent in shelter dogs. E. coli was detected in the fecal samples of all 61 and 77 shelter dogs tested in Chiba and Kanagawa, respectively. The AMR was tested against 20 antibiotics. E. coli isolates derived from 16.4% and 26.0% of samples from Chiba and Kanagawa exhibited resistance to at least one antibiotic, respectively. E. coli in samples from Chiba and Kanagawa prefectures were commonly resistant to ampicillin, piperacillin, streptomycin, kanamycin, tetracycline, and nalidixic acid; that from the Kanagawa Prefecture to cefazolin, cefotaxime, aztreonam, ciprofloxacin, and levofloxacin and that from Chiba Prefecture to chloramphenicol and imipenem. Multidrug-resistant bacteria were detected in 18 dogs from both regions; β-lactamase genes (blaTEM, blaDHA-1, blaCTX-M-9 group CTX-M-14), quinolone-resistance protein genes (qnrB and qnrS), and mutations in quinolone-resistance-determining regions (gyrA and parC) were detected. These results could partially represent the AMR data in shelter dogs in the Kanto Region of Japan.202235031646
1255120.9929Emergence of quinupristin/dalfopristin resistance among livestock-associated Staphylococcus aureus ST9 clinical isolates. Quinupristin/dalfopristin (Q/D) is a valuable alternative to vancomycin for the treatment of meticillin-resistant Staphylococcus aureus (MRSA) infections. However, not long after Q/D was approved, bacteria with resistance to this newer antimicrobial agent were reported. To investigate the prevalence of Q/D resistance, a total of 1476 non-duplicate S. aureus isolates, including 775 MRSA, from a Chinese tertiary hospital were selected randomly from 2003 to 2013. Of the 775 MRSA, 3 (0.4%) were resistant to Q/D. All meticillin-susceptible S. aureus were susceptible to Q/D. The prevalence of Q/D resistance among S. aureus was 0.2% (3/1476). The three isolates with Q/D resistance had the same antimicrobial resistance profile, except for cefaclor and chloramphenicol. All three Q/D-resistant MRSA were positive for five streptogramin B resistance genes (ermA, ermB, ermC, msrA and msrB) and two streptogramin A resistance genes (vatC and vgaA) as determined by PCR and DNA sequencing. MRSA WZ1031 belonged to ST9-MRSA-SCCmecV-t899, whilst MRSA WZ414 and WZ480 belonged to ST9-MRSA-SCCmecNT(non-typeable)-t899. ST9 has been reported predominantly in livestock-associated (LA) MRSA in some Asian countries. The three patients with these MRSA isolates were not livestock handlers and did not keep close contact with livestock. The origin of these important LA-MRSA isolates causing human infections is not known. Taken together, Q/D resistance, which was caused by a combination of ermA-ermB-ermC-msrA-msrB-vatC-vgaA, was first found among S. aureus clinical isolates in China. The present study is the first report of the emergence of human infections caused by ST9 LA-MRSA isolates with Q/D resistance.201425218154
1649130.9929Whole genome analysis and antimicrobial resistance assessment of Staphylococcus epidermidis isolated from food sources. Coagulase-negative staphylococci (CoNS), including Staphylococcus epidermidis, are commonly occurrence in a variety of food products. Historically considered non-pathogenic, these microorganisms were excluded from routine food safety monitoring protocols. However, their increasing involvement in nosocomial infections underscores their pathogenic potential. Emerging evidence suggests that the food chain may serve as a reservoir and transmission route for antibiotic-resistant bacteria. In this study, 26 S. epidermidis isolates obtained from ready-to-eat food were subjected to whole-genome sequencing and comprehensive bioinformatics analyses. The antimicrobial susceptibility of the isolates was also evaluated against a broad spectrum of agents including aminoglycosides, β-lactams, fluoroquinolones, glycopeptides, lincosamides, macrolides, nitrofurantoins, oxalidinones, phenicols, steroids, sulphonamides and tetracyclines. Sequence typing revealed the presence of 17 distinct sequence types (STs), with ST329 being the most frequently identified (8/26, 30.77 %), followed by ST88 and ST152 (each 2/26; 7.69 %). Notably, one isolate harbored a novel multi-locus sequence type. Phenotypically resistance to erythromycin was most prevalent (21/26, 80.77 %), followed by resistance to clindamycin (19/26, 73.08 %). Genomic analysis confirmed the presence of multiple antimicrobial resistance genes including norA/C, vanT, mecA, dfrC and multidrug resistance genes. The carrying of mobile genetic elements was demonstrated by 25/26 (96.15 %) strains. These findings indicate that S. epidermidis strains isolated from ready-to-eat foods not only exhibit multidrug resistance but also carry a diverse array of antimicrobial resistance genes. The potential for horizontal gene transfer to commensal or pathogenic bacteria highlights the need for increased surveillance and risk assessment concerning CoNS in the food supply.202540592212
1329140.9929First report of the Staphylococcus aureus isolate from subclinical bovine mastitis in the South of Brazil harboring resistance gene dfrG and transposon family Tn916-1545. The aim of this work was to identify at the molecular level the species of coagulase-positive staphylococci isolates from clinical and subclinical bovine mastitis samples in Southern Brazil, and to evaluate the antimicrobial resistance profile, as well as the presence of resistance genes. According to the PCR assay, all 31 isolates were classified as Staphylococcus aureus. The isolates were tested for resistance to penicillin, ampicillin, oxacillin, cefoxitin, cephalothin, ceftiofur, streptomycin, tobramycin, teicoplanin, erythromycin, clindamycin, enrofloxacin, sulfonamide, trimethoprim-sulfamethoxazole, trimethoprim, and tetracycline by the disk diffusion method. Most of the isolates were resistant to sulfonamide (20), followed by ampicillin and clindamycin (16). Twenty isolates were multidrug-resistant. PCR was used for the detection of several antimicrobial resistance genes (ereB, ermB, ermC, tetA, tetB, tetK, tetL, tetM, tetO, Tn916-1545, strA, strB, sul1, sul2, dfrA, dfrG, dfrK, blaZ, mecA, and mecC). The most prevalent antimicrobial resistance genes were tetK and tetL, ereB, followed by tetM, Tn916-1545 and blaZ, detected in 11, nine and four isolates, respectively. For all the tetM gene positive isolates, the presence of conjugative transposons of the Tn916-1545 family was detected. The presence of multidrug-resistant isolates, antimicrobial resistance genes and transposons suggests a potential risk of spreading multi-resistance genes to other bacteria.201729051059
2991150.9929Occurrence and antimicrobial resistance of Salmonella species and potentially pathogenic Escherichia coli in free-living seals of Canadian Atlantic and eastern Arctic waters. Seal populations in Canadian waters provide sustenance to coastal communities. There is potential for pathogenic and/or antimicrobial-resistant bacteria to transfer to humans through inadvertent faecal contamination of seal products. The objective of this study was to investigate the occurrence and potential antimicrobial resistance of Salmonella spp., Escherichia coli and Listeria monocytogenes in faecal samples collected from grey seals (Halichoerus grypus) in the Gulf of St. Lawrence and from ringed seals (Pusa hispida) in Frobisher Bay and Eclipse Sound, Nunavut, Canada. Grey seals were harvested during commercial hunts or during scientific sampling; ringed seals were collected by Inuit hunters during subsistence harvests. Virulence genes defining pathogenic E. coli were identified by PCR, and antimicrobial susceptibility testing was performed on recovered isolates. In grey seals, E. coli was detected in 34/44 (77%) samples, and pathogenic E. coli (extraintestinal E. coli [ExPEC], enteropathogenic E. coli [EPEC] or ExPEC/EPEC) was detected in 13/44 (29%) samples. Non-susceptibility to beta-lactams and quinolones was observed in isolates from 18 grey seals. In ringed seals from Frobisher Bay, E. coli was detected in 4/45 (9%) samples; neither virulence genes nor antimicrobial resistance was detected in these isolates. In ringed seals from Eclipse Sound, E. coli was detected in 8/50 (16%) samples and pathogenic E. coli (ExPEC and ExPEC/EPEC) in 5/50 (10%) samples. One seal from Eclipse Sound had an E. coli isolate resistant to beta-lactams. A monophasic Salmonella Typhimurium was recovered from 8/50 (16%) seals from Eclipse Sound. All Salmonella isolates were resistant to ampicillin, streptomycin, sulfisoxazole and tetracycline. L. monocytogenes was not detected in any sample. These findings suggest that seals may act as important sentinel species and as reservoirs or vectors for antimicrobial-resistant and virulent E. coli and Salmonella species. Further characterization of these isolates would provide additional insights into the source and spread of antimicrobial resistance and virulence genes in these populations of free-living seals.202337317052
2021160.9928Diversity of Plasmids and Antimicrobial Resistance Genes in Multidrug-Resistant Escherichia coli Isolated from Healthy Companion Animals. The presence and transfer of antimicrobial resistance genes from commensal bacteria in companion animals to more pathogenic bacteria may contribute to dissemination of antimicrobial resistance. The purpose of this study was to determine antimicrobial resistance gene content and the presence of genetic elements in antimicrobial resistant Escherichia coli from healthy companion animals. In our previous study, from May to August, 2007, healthy companion animals (155 dogs and 121 cats) from three veterinary clinics in the Athens, GA, USA area were sampled and multidrug-resistant E. coli (n = 36; MDR, resistance to ≥ 2 antimicrobial classes) were obtained. Of the 25 different plasmid replicon types tested by PCR, at least one plasmid replicon type was detected in 94% (34/36) of the MDR E. coli; four isolates contained as many as five different plasmid replicons. Nine replicon types (FIA, FIB, FII, I2, A/C, U, P, I1 and HI2) were identified with FIB, FII, I2 as the most common pattern. The presence of class I integrons (intI) was detected in 61% (22/36) of the isolates with eight isolates containing aminoglycoside- and/or trimethoprim-resistance genes in the variable cassette region of intI. Microarray analysis of a subset of the MDR E. coli (n = 9) identified the presence of genes conferring resistance to aminoglycosides (aac, aad, aph and strA/B), β-lactams (ampC, cmy, tem and vim), chloramphenicol (cat), sulfonamides (sulI and sulII), tetracycline [tet(A), tet(B), tet(C), tet(D) and regulator, tetR] and trimethoprim (dfrA). Antimicrobial resistance to eight antimicrobials (ampicillin, cefoxitin, ceftiofur, amoxicillin/clavulanic acid, streptomycin, gentamicin, sulfisoxazole and trimethoprim-sulfamethoxazole) and five plasmid replicons (FIA, FIB, FII, I1 and I2) were transferred via conjugation. The presence of antimicrobial resistance genes, intI and transferable plasmid replicons indicate that E. coli from companion animals may play an important role in the dissemination of antimicrobial resistance, particularly to human hosts during contact.201525653018
1296170.9928Prevalence and antimicrobial resistance of Salmonellaisolates from goose farms in Northeast China. BACKGROUND: Salmonella is one of the most important enteric pathogenic bacteria that threatened poultry health. AIMS: This study aimed to investigate the prevalence and antimicrobial resistance of Salmonella isolates in goose farms. METHODS: A total of 244 cloacal swabs were collected from goose farms to detect Salmonella in Northeast China. Antimicrobial susceptibility, and resistance gene distribution of Salmonella isolates were investigated. RESULTS: Twenty-one Salmonella isolates were identified. Overall prevalence of Salmonella in the present study was 8.6%. Among the Salmonella isolates, the highest resistance frequencies belonged to amoxicillin (AMX) (85.7%), tetracycline (TET) and trimethoprim/sulfamethoxazole (SXT) (81%), followed by chloramphenicol (CHL) (76.2%), florfenicol (FLO) (71.4%), kanamycin (KAN) (47.6%), and gentamycin (GEN) (38.1%). Meanwhile, only 4.8% of the isolates were resistant to ciprofloxacin (CIP) and cefotaxime (CTX). None of the isolates was resistant to cefoperazone (CFP) and colistin B (CLB). Twenty isolates (95%) were simultaneously resistant to at least two antimicrobials. Ten resistance genes were detected among which the bla (TEM-1), cmlA, aac(6')-Ib-cr, sul1, sul2, sul3, and mcr-1.1 were the most prevalent, and presented in all 21 isolates followed by tetB (20/21), qnrB (19/21), and floR (15/21). CONCLUSION: Results indicated that Salmonella isolates from goose farms in Northeast China exhibited multi-drug resistance (MDR), harboring multiple antimicrobial resistance genes. Our results will be useful to design prevention and therapeutic strategies against Salmonella infection in goose farms.202033584841
5432180.9928First large-scale study of antimicrobial susceptibility data, and genetic resistance determinants, in Fusobacterium necrophorum highlighting the importance of continuing focused susceptibility trend surveillance. OBJECTIVES: The objective of the study was to explore antimicrobial resistance gene determinant, and phenotypic antibiotic susceptibility, data for Fusobacterium necrophorum from a collection of UK strains. Antimicrobial resistance genes detected in publicly available assembled whole genome sequences were investigated for comparison. METHODS: Three hundred and eighty five F. necrophorum strains (1982-2019) were revived from cryovials (Prolab). Subsequent to sequencing (Illumina) and quality checking, 374 whole genomes were available for analysis. Genomes were interrogated, using BioNumerics (bioMérieux; v 8.1), for the presence of known antimicrobial resistance genes (ARGs). Agar dilution susceptibility results for 313 F. necrophorum isolates (2016-2021) were also examined. RESULTS: The phenotypic data for the 313 contemporary strains demonstrated potential resistance to penicillin in three isolates, using EUCAST v 11.0 breakpoints, and 73 (23%) strains using v 13.0 analysis. All strains were susceptible to multiple agents using v 11.0 guidance other than clindamycin (n = 2). Employing v 13.0 breakpoints, metronidazole (n = 3) and meropenem (n = 13) resistance were also detected. The tet(O), tet(M), tet(40), aph(3')-III, ant(6)-la and bla(OXA-85) ARGs were present in publicly available genomes. tet(M), tet(32), erm(A) and erm(B) were found within the UK strains, with correspondingly raised clindamycin and tetracycline minimum inhibitory concentrations. CONCLUSIONS: Susceptibility to antibiotics recommended for the treatment of F. necrophorum infections should not be assumed. With evidence of potential ARG transmission from oral bacteria, and the detection of a transposon-mediated beta-lactamase resistance determinant in F. necrophorum, surveillance of both phenotypic and genotypic antimicrobial susceptibility trends must continue, and increase.202336871786
5412190.9928Molecular basis of resistance to macrolides and other antibiotics in commensal viridans group streptococci and Gemella spp. and transfer of resistance genes to Streptococcus pneumoniae. We assessed the mechanisms of resistance to macrolide-lincosamide-streptogramin B (MLS(B)) antibiotics and related antibiotics in erythromycin-resistant viridans group streptococci (n = 164) and Gemella spp. (n = 28). The macrolide resistance phenotype was predominant (59.38%); all isolates with this phenotype carried the mef(A) or mef(E) gene, with mef(E) being predominant (95.36%). The erm(B) gene was always detected in strains with constitutive and inducible MLS(B) resistance and was combined with the mef(A/E) gene in 47.44% of isolates. None of the isolates carried the erm(A) subclass erm(TR), erm(A), or erm(C) genes. The mel gene was detected in all but four strains carrying the mef(A/E) gene. The tet(M) gene was found in 86.90% of tetracycline-resistant isolates and was strongly associated with the presence of the erm(B) gene. The cat(pC194) gene was detected in seven chloramphenicol-resistant Streptococcus mitis isolates, and the aph(3')-III gene was detected in four viridans group streptococcal isolates with high-level kanamycin resistance. The intTn gene was found in all isolates with the erm(B), tet(M), aph(3')-III, and cat(pC194) gene. The mef(E) and mel genes were successfully transferred from both groups of bacteria to Streptococcus pneumoniae R6 by transformation. Viridans group streptococci and Gemella spp. seem to be important reservoirs of resistance genes.200415328112