title: Prevalence of Plasmid-Mediated Fosfomycin Resistance Gene fosA3 Among CTX-M-Producing Escherichia coli Isolates from Chickens in China.
abstract: The aim of this study was to investigate the prevalence of fosfomycin resistance gene fosA3 and characterize plasmids harboring fosA3 among CTX-M-producing Escherichia coli from chickens in China. A total of 234 CTX-M-producing E. coli isolates collected from chickens from 2014 to 2016 were screened for the presence of plasmid-mediated fosfomycin resistance genes (fosA, fosA3, and fosC2). Clonal relatedness of fosA3-positive isolates was determined by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The genetic environment of fosA3 was analyzed by polymerase chain reaction (PCR) mapping. Plasmids were studied by using conjugation experiments, PCR-based replicon typing and plasmid MLST. Sixty-four (27.4%) fosA3-positive E. coli isolates were identified in this study. The gene blaCTX-M-55(31/64) was predominant among these strains, followed by blaCTX-M-14(18/64) and blaCTX-M-65(14/64). Various PFGE patterns and sequence types (STs) indicated that these isolates were clonally unrelated. Seven different genetic environments of fosA3 were identified and two new combinations (ISEcp1-blaCTX-M-65-ΔIS903D-IS26-fosA3-orf1-orf2-Δorf3-IS26 and IS26-ISEcp1-blaCTX-M-3-orf477-blaTEM-1-IS26-fosA3-orf1-orf2-Δorf3-IS26) were discovered for the first time. Conjugation experiments were successful for 47 isolates and 33 transconjugants harbored a single plasmid. Plasmids carrying fosA3 belonged to incompatibility group IncFII (17/33), IncI1 (2/33), IncHI2 (3/33), and IncB/O (1/33). F33:A-:B- plasmids carrying blaCTX-M-55, IncHI2/ST3 plasmids carrying blaCTX-M-65, and F2:A-:B-plasmids carrying blaCTX-M-55were found in E. coli isolates from different provinces. Our results revealed a considerable prevalence of fosA3 gene among CTX-M-producing E. coli with clonal diversity from chickens in China. The transmission of different kinds of plasmids is responsible for the dissemination of fosA3 in chicken farms in China.
authors.affiliation: 1 Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science, Sichuan University , Chengdu, China .|2 Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province , Chengdu, China .
authors.forename: Wei
authors.initials: W
authors.lastname: Jiang
authors.affiliation: 1 Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science, Sichuan University , Chengdu, China .|2 Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province , Chengdu, China .
authors.forename: Shuai
authors.initials: S
authors.lastname: Men
authors.affiliation: 1 Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science, Sichuan University , Chengdu, China .|2 Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province , Chengdu, China .
authors.forename: Linghan
authors.initials: L
authors.lastname: Kong
authors.affiliation: 1 Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science, Sichuan University , Chengdu, China .|2 Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province , Chengdu, China .
authors.forename: Suzhen
authors.initials: S
authors.lastname: Ma
authors.affiliation: 1 Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science, Sichuan University , Chengdu, China .|2 Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province , Chengdu, China .
authors.forename: Yongqiang
authors.initials: Y
authors.lastname: Yang
authors.affiliation: 1 Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science, Sichuan University , Chengdu, China .|2 Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province , Chengdu, China .
authors.forename: Yongxiang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: 1 Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science, Sichuan University , Chengdu, China .|2 Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province , Chengdu, China .
authors.forename: Qiwu
authors.initials: Q
authors.lastname: Yuan
authors.affiliation: 1 Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science, Sichuan University , Chengdu, China .|2 Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province , Chengdu, China .
authors.forename: Guangyang
authors.initials: G
authors.lastname: Cheng
authors.affiliation: 1 Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science, Sichuan University , Chengdu, China .|2 Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province , Chengdu, China .
authors.forename: Wencheng
authors.initials: W
authors.lastname: Zou
authors.affiliation: 1 Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science, Sichuan University , Chengdu, China .|2 Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province , Chengdu, China .|3 "985 Project" Science Innovative Platform for Resource and Environment Protection of Southwestern China, Sichuan University , Chengdu, China .
authors.forename: Hongning
authors.initials: H
authors.lastname: Wang
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015373:Bacterial Typing Techniques; D002645:Chickens / Q000382:microbiology*; D002681:China; D004269:DNA, Bacterial / Q000302:isolation & purification; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000235:genetics* / Q000302:isolation & purification; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D005578:Fosfomycin / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D010957:Plasmids / Q000235:genetics; D012093:Replicon; D017422:Sequence Analysis, DNA
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C000607929:FosA(3) protein, E coli; D005578:Fosfomycin
keywords: Gram-negative bacteria; extended spectrum beta-lactamases; genetic environments; plasmid analysis