국내에서 2003년에 분리된 Eschcerichia coli와 Klebsiella pneumoniae의 CTX-M형 Extended-Spectrum β-Lactamase 생성 현황

Abstract

Background : The aims of this study were to survey nationwide susceptibilities of Escherichia coli and Klebsiella pneumoniae isolates against cefotaxime and to determine the prevalences of CTX-M type extended-spectrum β-lactamases(ESBLs). Methods : During the period of February to July, 2003, E. coli and K. pneumoniae isolates were collected from 12 hospitals. Antimicrobial susceptibilities to cefotaxime were tested by the disk diffusion method. ESBL production was determined by the double disk synergy test. Cefotaxime-resistance of the ESBL-producers was transfered to E. coli DH5α and E. coli Top10-F by transformation. MICs of β-lactam antibiotics were determined by the agar dilution method. Searches for blaCTX-M genes was performed by PCR amplication; pIs of β-lactamases were determined by isoelectric focusing. Results : Among 230 isolates of E. coli and 232 isolates of K. pneumoniae, 27 (11.7%) and 79 (34.1%) were intermediate or resistant to cefotaxime, respectively. Twenty-four(10.4%) isolates of E. coli and 58 (25.0%) K. pneumoniae isolates showed positive results in the double disk synergy test. Three isolates of E. coli and 13 K. pneumoniae isolates harbored blaCTX-M-3 gene, 4 E. coli isolates harbored blaCTX-M-15 gene, and 1 E. coli and 5 K. pneumoniae isolates harbored blaCTX-M-14 gene.