title: Chromosomal location of the fosA3 and blaCTX-Mgenes in Proteus mirabilis and clonal spread of Escherichia coli ST117 carrying fosA3-positive IncHI2/ST3 or F2:A-:B- plasmids in a chicken farm.
abstract: The aim of this study was to investigate the spread and location of the fosA3 gene among Enterobacteriaceae from diseased broiler chickens. Twenty-nine Escherichia coli and seven Proteus mirabilis isolates recovered from one chicken farm were screened for the presence of plasmid-mediated fosfomycin resistance genes by PCR. The clonal relatedness of fosA3-positive isolates, the transferability and location of fosA3, and the genetic context of the fosA3 gene were determined. Seven P. mirabilis isolates with three different pulsed-field gel electrophoresis (PFGE) patterns and five E. coli isolates belonging to sequence type 117 (ST117) and phylogenetic group D were positive for fosA3 and all carried the blaCTX-Mgene. In E. coli, the genetic structures IS26-ISEcp1-blaCTX-M-65-IS26-fosA3-1758 bp-IS26 and IS26-ISEcp1-blaCTX-M-3-blaTEM-1-IS26-fosA3-1758 bp-IS26 were present on transferable IncHI2/ST3 and F2:A-:B- plasmids, respectively. However, fosA3 was located on the chromosome of the seven P. mirabilis isolates. IS26-ISEcp1-blaCTX-M-65-IS26-fosA3-1758 bp-IS26 and IS26-blaCTX-M-14-611 bp-fosA3-1222 bp-IS26 were detected in three and four P. mirabilis isolates, respectively. Minicircles that contained both fosA3 and blaCTX-M-65were shared between E. coli and P. mirabilis. This is the first report of the fosA3 gene integrated into the chromosome of P. mirabilis isolates with the blaCTX-Mgene. The emergence and clonal spread of avian pathogenic E. coli ST117 with the feature of multidrug resistance and high virulence are a serious problem.
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, National Reference Laboratory of Veterinary Drug Residues (SCAU), South China Agricultural University, Guangzhou, China.
authors.forename: Dandan
authors.initials: D
authors.lastname: He
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, National Reference Laboratory of Veterinary Drug Residues (SCAU), South China Agricultural University, Guangzhou, China.
authors.forename: Lanping
authors.initials: L
authors.lastname: Liu
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, National Reference Laboratory of Veterinary Drug Residues (SCAU), South China Agricultural University, Guangzhou, China.
authors.forename: Baowei
authors.initials: B
authors.lastname: Guo
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, National Reference Laboratory of Veterinary Drug Residues (SCAU), South China Agricultural University, Guangzhou, China.
authors.forename: Shengjun
authors.initials: S
authors.lastname: Wu
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, National Reference Laboratory of Veterinary Drug Residues (SCAU), South China Agricultural University, Guangzhou, China.
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Chen
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, National Reference Laboratory of Veterinary Drug Residues (SCAU), South China Agricultural University, Guangzhou, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, National Reference Laboratory of Veterinary Drug Residues (SCAU), South China Agricultural University, Guangzhou, China.
authors.forename: Zhenling
authors.initials: Z
authors.lastname: Zeng
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, National Reference Laboratory of Veterinary Drug Residues (SCAU), South China Agricultural University, Guangzhou, China. Electronic address: jhliu@scau.edu.cn.
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Liu
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D002353:Carrier State / Q000382:microbiology / Q000662:veterinary*; D002645:Chickens / Q000382:microbiology; D004756:Enterobacteriaceae Infections / Q000382:microbiology / Q000662:veterinary*; D004926:Escherichia coli / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D000072480:Farms; D022761:Gene Transfer, Horizontal; D058889:Molecular Typing; D010957:Plasmids / Q000032:analysis* / Q000145:classification; D016133:Polymerase Chain Reaction; D011513:Proteus mirabilis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D001618:beta-Lactamases
keywords: CTX-M; Escherichia coli; Fosfomycin; Plasmid; Poultry; Proteus mirabilis