Occurrence of Extended-Spectrum β-Lactamases in Members of the Genus Shigella in the Republic of Korea

Abstract

ABSTRACT A nationwide survey was carried out in Korea to assess the prevalence of Shigella strains producing extended-spectrum β-lactamases (ESBLs). From 1991 to 2002, 5,911 clinical strains were isolated and screened for resistance to extended-spectrum cephalosporins. Twenty of the Shigella isolates were ESBL positive, based on the synergistic effects between clavulanate and selected β-lactams (ceftazidime and cefotaxime). Nucleotide sequence analysis of these isolates revealed that they harbored bla TEM-19 (eight isolates), bla TEM-15 (five isolates), bla TEM-52 (six isolates), bla TEM-17 (one isolate), bla TEM-20 (one isolate), and bla CTX-M-14 (three isolates). All the ESBL-encoding genes in this study were carried in conjugable plasmids. Thus, TEM-19, TEM-15, TEM-52, and CTX-M-14 β-lactamases can be considered common Korean ESBL types in Shigella sonnei and are probably transmitted through interspecies spread between medical facilities and the community in Korea. This is the first report of the presence of TEM-17, TEM-19, and TEM-20 in Korea and in S. sonnei .