Molecular characterization of Escherichia coli strains isolated from retail meat that harbor blaCTX-Mand fosA3 genes

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

Research output: Journal article publicationJournal articleAcademic researchpeer-review

19 Citations (Scopus)


A total of 55 cefotaxime-resistant Escherichia coli isolates 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 a blaCTX-Mgene, with the blaCTX-M-1group being the most common type. blaCMY-2 was detected in 16 isolates, alone or in combination with other extended-spectrum β-lactamase (ESBL) determinants. Importantly, the fosA3 gene, which encodes fosfomycin resistance, was detected in 12 isolates, with several being found to reside in the conjugative plasmid that harbored the blaCTX-Mgene. The insertion sequence IS26 was observed upstream of some of the blaCTX-M-55and fosA3 genes. Conjugation experiments showed that blaCTX-Mgenes from 15 isolates were transferrable, with Inc I1 and Inc FII being the most prevalent replicons. High clonal diversity was observed among the blaCTX-Mproducers, suggesting that horizontal transfer of the blaCTX-Mgenes among E. coli strains in retail meats is a common event and that such strains may constitute an important reservoir of blaCTX-Mgenes, which may be readily disseminated to other potential human pathogens.
Original languageEnglish
Pages (from-to)2450-2455
Number of pages6
JournalAntimicrobial Agents and Chemotherapy
Issue number4
Publication statusPublished - 1 Apr 2016

ASJC Scopus subject areas

  • Pharmacology
  • Pharmacology (medical)
  • Infectious Diseases

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