[Prevalence of extended-spectrum beta-lactamases in Escherichia coli and Klebsiella pneumoniae from Daejeon].
BACKGROUND
Extended-spectrum beta-lactamases (ESBLs) are cephalosporinases that confer resistance to a wide variety of oxyimino cephalosporins and create serious therapeutic problems. Although ESBLs have been reported with increasing frequency in Korea, their prevalence and genotypic distribution in Daejeon remain unknown. This study was designed to evaluate the occurrence and genotypic distributions of ESBL-producing Escherichia coli and Klebsiella pneumoniae in Daejeon.


METHODS
We tested a total of 427 isolates of E. coli and K. pneumoniae at Chungnam National University Hospital during the period from March to September 2006. ESBL production was determined by the Clinical and Laboratory Standards Institute ESBL confirmatory test; minimum inhibitory concentrations of beta-lactam antibiotics were determined by the broth dilution method. The ceftazidime or cefotaxime resistance of the ESBL-producers was transferred to azide-resistant E. coli J53 by conjugation. Searches for ESBL genes were performed by PCR amplification, and the genotypes of ESBLs were determined by direct nucleotide sequence analysis of the amplified products. The pIs of ESBL were determined by isoelectric focusing.


RESULTS
The proportion of ESBL-producers was 10% of the E. coli and 28% of the K. pneumoniae isolates. The prevalence of ESBL-positive isolates was 60% in the intensive care units and 18.7% in the general wards. The most prevalent ESBL genotype in E. coli isolates was bla(CTX-M) and in K. pneumoniae was bla(SHV-12).


CONCLUSIONS
E. coli and K. pneumoniae isolates producing SHV-12 or CTX-M-type ESBLs are widespread in Daejeon.
Ko
Chi Seon
CS
Department of Laboratory Medicine, Chungnam National University Hospital, Daejeon, Korea.
Sung
Ji Yun
JY
Koo
Sun Hoe
SH
Kwon
Gye Cheol
GC
Shin
So Yeon
SY
Park
Jong Woo
JW
D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D052978:Disk Diffusion Antimicrobial Tests; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000382:microbiology; D005838:Genotype; D006801:Humans; D007710:Klebsiella Infections / Q000188:drug therapy / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000201:enzymology / Q000302:isolation & purification; D007723:Korea; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000032:analysis*; D047090:beta-Lactams / Q000627:therapeutic use
D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D001618:beta-Lactamases