Molecular Characterization of Escherichia coli Strains Isolated from Retail Meat That Harbor blaCTX-M and fosA3 Genes

Miaomiao Xie; Dachuan Lin; Kaichao Chen; Edward Wai Chi Chan; Wen Yao; Sheng Chen

doi:10.1128/AAC.03101-15

Molecular Characterization of Escherichia coli Strains Isolated from Retail Meat That Harbor blaCTX-M and fosA3 Genes

Antimicrob Agents Chemother. 2016 Mar 25;60(4):2450-5. doi: 10.1128/AAC.03101-15. Print 2016 Apr.

Authors

Miaomiao Xie¹, Dachuan Lin², Kaichao Chen², Edward Wai Chi Chan², Wen Yao³, Sheng Chen⁴

Affiliations

¹ College of Animal Science and Technology, Nanjing Agriculture University, Nanjing, People's Republic of China Shenzhen Key Laboratory for Food Biological Safety Control, Food Safety and Technology Research Centre, The Hong Kong PolyU Shenzhen Research Institute, Shenzhen, People's Republic of China.
² Shenzhen Key Laboratory for Food Biological Safety Control, Food Safety and Technology Research Centre, The Hong Kong PolyU Shenzhen Research Institute, Shenzhen, People's Republic of China State Key Laboratory of Chirosciences, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
³ College of Animal Science and Technology, Nanjing Agriculture University, Nanjing, People's Republic of China [email protected] [email protected].
⁴ Shenzhen Key Laboratory for Food Biological Safety Control, Food Safety and Technology Research Centre, The Hong Kong PolyU Shenzhen Research Institute, Shenzhen, People's Republic of China State Key Laboratory of Chirosciences, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong [email protected] [email protected].

Abstract

A total of 55 cefotaxime-resistantEscherichia coliisolates were obtained from retail meat products purchased in Shenzhen, China, during the period November 2012 to May 2013. Thirty-seven of these 55 isolates were found to harbor ablaCTX-Mgene, with theblaCTX-M-1group being the most common type.blaCMY-2was detected in 16 isolates, alone or in combination with other extended-spectrum β-lactamase (ESBL) determinants. Importantly, thefosA3gene, which encodes fosfomycin resistance, was detected in 12 isolates, with several being found to reside in the conjugative plasmid that harbored theblaCTX-Mgene. The insertion sequence IS26was observed upstream of some of theblaCTX-M-55andfosA3genes. Conjugation experiments showed thatblaCTX-Mgenes from 15 isolates were transferrable, with Inc I1 and Inc FII being the most prevalent replicons. High clonal diversity was observed among theblaCTX-Mproducers, suggesting that horizontal transfer of theblaCTX-Mgenes amongE. colistrains in retail meats is a common event and that such strains may constitute an important reservoir ofblaCTX-Mgenes, which may be readily disseminated to other potential human pathogens.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Anti-Bacterial Agents / pharmacology
Chickens
China
Conjugation, Genetic
Drug Resistance, Multiple, Bacterial / genetics*
Escherichia coli / classification
Escherichia coli / drug effects
Escherichia coli / genetics*
Escherichia coli / isolation & purification
Escherichia coli Proteins / genetics*
Fosfomycin / pharmacology
Gene Expression
Humans
Isoenzymes / genetics
Meat / analysis
Meat / microbiology*
Microbial Sensitivity Tests
Multilocus Sequence Typing
Phylogeny
Plasmids / chemistry
Plasmids / metabolism
Replicon
Swine
beta-Lactamases / genetics*

Substances

Anti-Bacterial Agents
Escherichia coli Proteins
FosA(3) protein, E coli
Isoenzymes
Fosfomycin
beta-Lactamases
beta-lactamase CTX-M, E coli