Prevalence & Diversity of Extended-Spectrum β-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae Isolates in Korea

Abstract

Background : Increase in extended-spectrum p-lactamase(ESBL)-producing Escherichia coli and Klebsiella pneumoniae have beeh reported in Korea. The aim of this study was to determine the na￢tionwide prevalence of ESBL-producing E. coli and K pneumoniae, and to investigate the types of ESBLs.

Methods : A total of 2,221 E. coli and 11,128 K pneumoniae consecutive isolates were yearly col￢lected from 12 hospitals in 1999 and 2000. ESBL production was performed by National Committee for Clinical Laboratory Standards methods and double synergy tests. The type of ESBL was deter￢mined by polymerase chain reaction (PCR), isoelectric focusing, and nucleotide sequence analysis.

Results: ESBL-producing E. coli and K pneumoniae isolates were detected from all 12 hospitals participated. The proportion of ESBL-producers was 9.1%(2.0-19.6%) of the E. coli and 29.2% (10.0-60.8%) of the K pneumoniae isolates. Among the 22 isolates sequenced, SHV-12 was found in six isolates, SHV-2a in three isolates, TEM-52 in five isolates, TEM-106 in three isolates, and each of TEM-15, TEM-20, TEM-43, and TEM-107 in one isolate. CTX-M-14 was also found in one isolate.

Conclusion: ESBL-producing E. coli and K pneumoniae are widespred to all levels of Korean hospitals. The most common types of ESBLs in Korea are SHV-12, SHV-2a, and TEM-52. In addition, we also identified new TEM-derived ESBLs. (Korean J Ciin Microbiol 2003;6(2):149-155)