Journal of Microbiology and Biotechnology, 2014, 01, 421─426

Characterization of CTX-M-Type Extended-Spectrum Beta-Lactamase-Producing Diarrheagenic Escherichia coli Isolates in the Republic of Korea During 2008-2011

Junyoung Kim

Abstract

To characterize the extended-spectrum beta-lactamases (ESBLs) in diarrheagenic Escherichia coli from Korea in 2008-2011, we screened seven enterotoxigenic E. coli (ETEC) and one enteroaggregative E. coli (EAEC) that produce ESBLs from a nationwide survey. All eight isolates produced CTX-M-type ESBLs, including CTX-M-12 (n = 4), CTX-M-14 (n = 2), and CTX-M-15 (n = 2). PCR-based replicon typing indicated that the blaCTX-M-12 genes of four ETEC isolates were carried on a conjugative IncF plasmid, whereas the blaCTX-M-14 of one EAEC was located on an IncK plasmid. This is the first report of the occurrence of blaCTX-M genes in clinical isolates of EAEC in Korea. The ESBL-producing isolates were shown to be different based on pulsed-field gel electrophoresis and multilocus sequence typing, whereas the four isolates with CTX-M-12 were clonally related. These observations raise an alarm for the spread of plasmid-mediated resistance to ESBL among diarrheagenic E. coli.

• ISBN or ISSN: 1017-7825

• 본 연구는 질병관리본부 연구개발과제(과제번호 2012-N41001-00) 연구비를 지원받아 수행되었습니다.
• This research was supported by a fund(code 2012-N41001-00) by Research of Korea Centers for Disease Control and Prevention.