Prevalence of Plasmid-Mediated Fosfomycin Resistance Gene fosA3 Among CTX-M-Producing Escherichia coli Isolates from Chickens in China

Wei Jiang; Shuai Men; Linghan Kong; Suzhen Ma; Yongqiang Yang; Yongxiang Wang; Qiwu Yuan; Guangyang Cheng; Wencheng Zou; Hongning Wang

doi:10.1089/fpd.2016.2230

Prevalence of Plasmid-Mediated Fosfomycin Resistance Gene fosA3 Among CTX-M-Producing Escherichia coli Isolates from Chickens in China

Foodborne Pathog Dis. 2017 Apr;14(4):210-218. doi: 10.1089/fpd.2016.2230. Epub 2017 Feb 17.

Authors

Wei Jiang^{1

2}, Shuai Men^{1

2}, Linghan Kong^{1

2}, Suzhen Ma^{1

2}, Yongqiang Yang^{1

2}, Yongxiang Wang^{1

2}, Qiwu Yuan^{1

2}, Guangyang Cheng^{1

2}, Wencheng Zou^{1

2}, Hongning Wang^{1

2

3}

Affiliations

¹ 1 Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science, Sichuan University , Chengdu, China .
² 2 Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province , Chengdu, China .
³ 3 "985 Project" Science Innovative Platform for Resource and Environment Protection of Southwestern China, Sichuan University , Chengdu, China .

PMID: 28379732
DOI: 10.1089/fpd.2016.2230

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 bla_CTX-M-55 (31/64) was predominant among these strains, followed by bla_CTX-M-14 (18/64) and bla_CTX-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-bla_CTX-M-65-ΔIS903D-IS26-fosA3-orf1-orf2-Δorf3-IS26 and IS26-ISEcp1-bla_CTX-M-3-orf477-bla_TEM-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 bla_CTX-M-55, IncHI2/ST3 plasmids carrying bla_CTX-M-65, and F2:A-:B-plasmids carrying bla_CTX-M-55 were 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.

Keywords: Gram-negative bacteria; extended spectrum beta-lactamases; genetic environments; plasmid analysis.

MeSH terms

Animals
Anti-Bacterial Agents / pharmacology*
Bacterial Typing Techniques
Chickens / microbiology*
China
DNA, Bacterial / isolation & purification
Drug Resistance, Multiple, Bacterial / genetics*
Electrophoresis, Gel, Pulsed-Field
Escherichia coli / genetics*
Escherichia coli / isolation & purification
Escherichia coli Proteins / genetics
Escherichia coli Proteins / metabolism
Fosfomycin / pharmacology*
Microbial Sensitivity Tests
Multilocus Sequence Typing
Plasmids / genetics
Replicon
Sequence Analysis, DNA

Substances

Anti-Bacterial Agents
DNA, Bacterial
Escherichia coli Proteins
FosA(3) protein, E coli
Fosfomycin