Frequency of Extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase Genes in Escherichia coli and Klebsiella pneumoniae over a Three-year Period in a University Hospital in Korea

Abstract

Background : The aim of this study was to determine the yearly prevalence and genotype distribution of extended-spectrum b-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae collected over a 3-yr period in Gwangju, Korea.Methods : Clinical isolates of E. coli and K. pneumoniae collected at Chosun University Hospital from September 15, 2005 to September 14, 2008 were evaluated. Antimicrobial susceptibility testing was performed using the Vitek II system (bioMe@ rieux, USA) and agar dilution methods. Screening for ESBL and AmpC b-lactamase genes was performed using PCR amplification of plasmid DNA followed by direct sequencing of the PCR products.Results : The percentage of ESBL-producing isolates was 12.6% (196/1,550) for E. coli and 26.2% (294/1,121) for K. pneumoniae. The ESBL gene sequencing results showed that the most prevalent ESBL types were CTX-M (93.5%) and SHV (12.9%) in E. coli, and SHV (73.2%) and CTX-M (46.3%) in K. pneumoniae. The most common ESBL in E. coli was CTX-M-15-like, followed by CTX-M-14-like, SHV-2a-like, and SHV-12-like. The most prevalent ESBL type in K. pneumoniae was SHV-12, followed by CTX-M-14-like and CTX-M-15-like. Fifty-one percent (21/41) of ESBL-producing K. pneumoniae with ESBL types verified by sequencing also had DHA-1-like AmpC b-lactamases. However, none of the ESBL-producing E. coli was positive in the AmpC b-lactamase PCR analysis.Conclusions : In this study, the most common types of class A ESBLs identified were CTX-M-15-like in E. coli and SHV-12-like in K. pneumoniae. (Korean J Lab Med 2010;30:616-23)

The Antimicrobial Susceptibility of Klebsiella pneumoniae from Community Settings in Taiwan, a Trend Analysis

“…CMY-type gene was the most common AmpC β-lactamase gene among Enterobacteriaceae isolates in Asia-Pacific region, according to results from the SMART study32. However, several studies from Korea also demonstrated that DHA was the predominant type of AmpC β-lactamase gene among their K. pneumoniae isolates1218. Together with our results, these results indicated a geographical distribution difference of endemic AmpC β-lactamase genes.…”

“…The overall prevalence of ESBL-producing K. pneumoniae isolates varies widely in different studies, from 3.6% in Canada, 16% in U.S.A, to 26.2% in Korea, and 39.3% in Eastern Europe89101112. The Study for Monitoring Antimicrobial Resistance Trends (SMART) has shown that the prevalence of ESBL-producing K. pneumoniae isolates from intra-abdominal infection (IAI) was also high13.…”

Prevalence of acquired fosfomycin resistance among extended-spectrum -lactamase-producing Escherichia coli and Klebsiella pneumoniae clinical isolates in Korea and IS26-composite transposon surrounding fosA3

“…Considering that all the isolates harbouring fosA3 co-harboured bla CTX-M , this difference might be derived from the fact that the dominant type of ESBL in E. coli and K. pneumoniae in Korea is bla CTX-M and bla SHV , respectively. 14,15 The clones of the isolates harbouring fosA3, determined by MLST, were diverse: the STs of the five E. coli isolates were ST1, ST1, ST533, ST2 and ST86 and those of the two K. pneumoniae isolates were ST11 and ST101. Moreover, in the two E. coli isolates belonging to the same ST, the plasmid Inc types were different.…”

Characteristics of the Molecular Epidemiology of CTX-M-Producing Escherichia coli Isolated from a Tertiary Hospital in Daejeon, Korea

“…Recently, CTX-M-14 and CTX-M-15 ESBLs have been shown to have higher activity against cefotaxime than against other oxyimino-β-lactam substrates and to be expressed by most E. coli isolates worldwide [13][14][15]19]. Several studies conducted in Korea have shown that 10-17% of E. coli strains produce ESBLs and that the prevalence of CTX-M-producing strains has increased to 17-92% since the first report about CTX-M in 2001 [8][9][10][11].…”