title: Comparison of plasmids coharboring 16s rrna methylase and extended-spectrum β-lactamase genes among Escherichia coli isolates from pets and poultry.
abstract: A total of 247 Escherichia coli isolates (148 from diseased or dead poultry and 99 from diseased pets in the People's Republic of China) were screened for extended-spectrum β-lactamase (ESBL) determinants by PCR and sequencing. Then, 16S rRNA methylase genes were detected among ESBL-producing isolates. Clonal relatedness of the E. coli isolates was examined by pulsed-field gel electrophoresis. Conjugation experiments were performed to investigate the association of 16S rRNA methylases and ESBLs, and plasmid contents were also characterized. Among 247 E. coli isolates, 74 (29.96%) isolates were positive for blaCTX-M genes, 42 from pets (12 from cats and 30 from dogs) and 32 from poultry (12 from chickens and 20 from ducks). The most common CTX-M type in isolates from pets was blaCTX-M-14, whereas blaCTX-M-27 was the most common for poultry. rmtB was dectected in 39 of the 74 blaCTX-M-positive isolates, 18 from pets and 21 from poultry. One strain from a pet was found to harbor blaCTX-M-14, blaCTX-M-15, and rmtB. blaCTX-M and rmtB were found to be colocated on the same transferable plasmid in 16 isolates. These genes were on the same or similar plasmids (eight F2:A-:B- and two IncN) in isolates from ducks, whereas they were colocated on the similar F2:A-:B- or similar F33:A-:B- plasmids in isolates of pets origin. In conclusion, similar F2:A-:B- plasmids and similar F33:A-:B- plasmids are responsible for the dissemination of both rmtB and blaCTX-Mgenes in E. coli isolates from poultry and pets, respectively.
authors.affiliation: College of Veterinary Medicine, National Reference Laboratory of Veterinary Drug Residues (SCAU), South China Agricultural University, Guangzhou 510642, People's Republic of China.
authors.forename: Xiao-Ping
authors.initials: XP
authors.lastname: Liao
authors.forename: Bao-Tao
authors.initials: BT
authors.lastname: Liu
authors.forename: Qiu-E
authors.initials: QE
authors.lastname: Yang
authors.forename: Jian
authors.initials: J
authors.lastname: Sun
authors.forename: Liang
authors.initials: L
authors.lastname: Li
authors.forename: Liang-Xing
authors.initials: LX
authors.lastname: Fang
authors.forename: Ya-Hong
authors.initials: YH
authors.lastname: Liu
mesh_terms: D000818:Animals; D002415:Cats; D002681:China; D003227:Conjugation, Genetic; D004285:Dogs; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000201:enzymology* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000235:genetics / Q000382:microbiology* / Q000662:veterinary; D029968:Escherichia coli Proteins / Q000235:genetics*; D008780:Methyltransferases / Q000235:genetics; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011200:Poultry; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D029968:Escherichia coli Proteins; D012336:RNA, Ribosomal, 16S; D008780:Methyltransferases; C540682:RmtB protein, E coli; C035181:rRNA (adenosine-O-2'-)methyltransferase; D001618:beta-Lactamases