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Molecular characterization of extended-spectrum-β-lactamase-producing and plasmid-mediated AmpC β-lactamase-producing Escherichia coli isolated from stray dogs in South Korea.

Authors :
Tamang MD
Nam HM
Jang GC
Kim SR
Chae MH
Jung SC
Byun JW
Park YH
Lim SK
Source :
Antimicrobial agents and chemotherapy [Antimicrob Agents Chemother] 2012 May; Vol. 56 (5), pp. 2705-12. Date of Electronic Publication: 2012 Feb 21.
Publication Year :
2012

Abstract

A total of 47 extended-spectrum-cephalosporin-resistant Escherichia coli strains isolated from stray dogs in 2006 and 2007 in the Republic of Korea were investigated using molecular methods. Extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase phenotypes were identified in 12 and 23 E. coli isolates, respectively. All 12 ESBL-producing isolates carried bla(CTX-M) genes. The most common CTX-M types were CTX-M-14 (n = 5) and CTX-M-24 (n = 3). Isolates producing CTX-M-3, CTX-M-55, CTX-M-27, and CTX-M-65 were also identified. Twenty-one of 23 AmpC β-lactamase-producing isolates were found to carry bla(CMY-2) genes. TEM-1 was associated with CTX-M and CMY-2 β-lactamases in 4 and 15 isolates, respectively. In addition to bla(TEM-1), two isolates carried bla(DHA-1), and one of them cocarried bla(CMY-2). Both CTX-M and CMY-2 genes were located on large (40 to 170 kb) conjugative plasmids that contained the insertion sequence ISEcp1 upstream of the bla genes. Only in the case of CTX-M genes was there an IS903 sequence downstream of the gene. The spread of ESBLs and AmpC β-lactamases occurred via both horizontal gene transfer, accounting for much of the CTX-M gene dissemination, and clonal spread, accounting for CMY-2 gene dissemination. The horizontal dissemination of bla(CTX-M) and bla(CMY-2) genes was mediated by IncF and IncI1-Iγ plasmids, respectively. The clonal spread of bla(CMY-2) was driven mainly by E. coli strains of virulent phylogroup D lineage ST648. To our knowledge, this is the first report of bla(DHA-1) in E. coli strains isolated from companion animals. This study also represents the first report of CMY-2 β-lactamase-producing E. coli isolates from dogs in the Republic of Korea.

Details

Language :
English
ISSN :
1098-6596
Volume :
56
Issue :
5
Database :
MEDLINE
Journal :
Antimicrobial agents and chemotherapy
Publication Type :
Academic Journal
Accession number :
22354297
Full Text :
https://doi.org/10.1128/AAC.05598-11