Emergence of Plasmid-Mediated CMY-2 beta -Lactamase Produced by Clinical Isolates of Escherichia coli in Korea / 대한진단검사의학회지

ABSTRACT

BACKGROUND: Of the plasmid-mediated AmpC beta-lactamases (ABLs), CMY-2 is the most prevalent and is distributed in many countries. However, little is known about the emergence and characteristics of CMY-2 among Escherichia coli isolates in Korea. The aims of this study were to detect the emergence of the CMY-2 beta-lactamase in clinical isolates of E. coli from various regions in Korea. METHODS: Eighteen cefoxitin non-susceptible isolates of 1, 130 consecutive, nonrepeat isolates of E. coli at five university hospitals were tested for antimicrobial susceptibility by the broth microdilution method. The cefoxitin non-susceptible isolates were further investigated by AmpC disk tests, double disk synergy (DDS) tests, isoelectric focusing, CMY-2-specific PCR, DNA sequencing, and plasmid analysis. RESULTS: Seven (0.6%) isolates of plasmid-mediated ABL-producing E. coli were found at three of the five hospitals; all seven isolates produced CMY-2 beta-lactamase and one of the isolates was also tested positive by the DDS test. All isolates demonstrated different plasmid patterns by plasmid analysis. CONCLUSIONS: Our data indicate that CMY-2-producing E. coli has emerged and is prevalent in the medical institution in Korea. Therefore, constant surveillance is needed to prevent its further spread.