title: Co-prevalance of PMQR and 16S rRNA methylase genes in clinical Escherichia coli isolates with high diversity of CTX-M from diseased farmed pigeons.
abstract: In the present study, we determined the molecular epidemiology of extended-spectrum β-lactamases (ESBLs) in Escherichia coli isolated from diseased farmed pigeons in China. A total of 71 E. coli isolates were collected from three pigeon farms from 2011 to 2012 and screened for the presence of the ESBL genes. The ESBLs producers were further tested for the presence of PMQR-encoding genes as well as the 16S rRNA methylase gene using PCR and DNA sequence analysis. Co-transfer of plasmids encoding for ESBLs, PMQR determinants and/or 16S rRNA methylase gene was performed by conjugation into E. coli. The genetic relatedness and plasmid replicon type were determined. A total of 41 ESBLs producers were identified. Only CTX-M type ESBLs were detected, with the most common CTX-M types being CTX-M-65 (n=17), CTX-M-27 (n=11), CTX-M-55 (n=10). Thirty-eight CTX-M-positive isolates were found to harbor at least one PMQR gene, with aac(6')-Ib-cr (n=32) and oqxAB (n=21) being the most prevalent. The rmtB was the only prevalent 16S rRNA methylase gene detected in 24 (58.1%) CTX-M-positive isolates. Although most of the CTX-M producers had distinct pulsotypes, clonal transmission in the same farm was observed. blaCTX-M genes were carried by IncF alone or in combination with IncK plasmids with three different sizes, including 76.8Kb (n=20), 194Kb (n=5), 104.5Kb (n=2). PFGE profiles of CTX-M-positive E. coli isolates indicated potential horizontal spread of these multidrug resistant strains along with those CTX-M encoding genes. Our findings highlight the importance of pigeons as a reservoir of multiple antimicrobial resistance genes.
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University (SCAU), Guangzhou 510642, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Yang
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University (SCAU), Guangzhou 510642, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
authors.affiliation: Laboratory of Clinical Microbiology, Institute of Veterinary Medicine, Guangdong Academy of Agriculture Sciences, Guangzhou 510640, China.
authors.forename: Dian-Hong
authors.initials: DH
authors.lastname: Lü
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University (SCAU), Guangzhou 510642, China; Laboratory of Clinical Microbiology, Institute of Veterinary Medicine, Guangdong Academy of Agriculture Sciences, Guangzhou 510640, China.
authors.forename: Wen-Hui
authors.initials: WH
authors.lastname: Zhang
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University (SCAU), Guangzhou 510642, China.
authors.forename: Si-Qi
authors.initials: SQ
authors.lastname: Ren
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University (SCAU), Guangzhou 510642, China.
authors.forename: Ya-Hong
authors.initials: YH
authors.lastname: Liu
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University (SCAU), Guangzhou 510642, China.
authors.forename: Zhen-Ling
authors.initials: ZL
authors.lastname: Zeng
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University (SCAU), Guangzhou 510642, China. Electronic address: hxjiang@scau.edu.cn.
authors.forename: Hong-Xia
authors.initials: HX
authors.lastname: Jiang
mesh_terms: D000818:Animals; D002681:China / Q000453:epidemiology; D010856:Columbidae / Q000382:microbiology*; D004926:Escherichia coli / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000235:genetics*; D014644:Genetic Variation; D008780:Methyltransferases / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D011201:Poultry Diseases / Q000453:epidemiology / Q000382:microbiology*; D015995:Prevalence; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D029968:Escherichia coli Proteins; D008780:Methyltransferases; C035181:rRNA (adenosine-O-2'-)methyltransferase; D001618:beta-Lactamases
keywords: CTX-M; E. coli; Multi-drug resistance