title: CTX-M and SHV-12 beta-lactamases are the most common extended-spectrum enzymes in clinical isolates of Escherichia coli and Klebsiella pneumoniae collected from 3 university hospitals within Korea.
abstract: Among the 443 clinical isolates of Escherichia coli and Klebsiella spp. collected between June and November 2003 from 3 university hospitals in Korea, 62 isolates were confirmed as extended-spectrum beta-lactamase (ESBL)- or plasmid-mediated AmpC beta-lactamase-producers by double disk synergy test, PCR and sequencing for beta-lactamase genes. The most frequently identified ESBL gene among E. coli and K. pneumoniae isolates was bla(SHV-12) and bla(CTX-M) (bla(CTX-M-9), bla(CTX-M-14), bla(CTX-M-3), and bla(CTX-M-15)). Four kinds of plasmid-mediated AmpC beta-lactamases, ACT-1, CMY-1, CMY-2, and DHA-1, were detected. ESBL production was associated with high levels of resistance to tetracycline, sulfisoxazole, streptomycin, kanamycin, gentamicin and tobramycin when compared to non-ESBL producing isolates. Conclusively, this study suggests that the CTX-M beta-lactamases are prevalent and various kinds of plasmid-mediated AmpC enzymes are distributed in clinical isolates of E. coli and Klebsiella spp. in Korea.
authors.affiliation: Department of Microbiology, Dankook University College of Medicine, Chonan City, Choongnam 330-715, Republic of Korea. minkim@dankook.ac.kr
authors.forename: Jungmin
authors.initials: J
authors.lastname: Kim
authors.forename: Yu-Mi
authors.initials: YM
authors.lastname: Lim
authors.forename: Insoo
authors.initials: I
authors.lastname: Rheem
authors.forename: Yeonhee
authors.initials: Y
authors.lastname: Lee
authors.forename: Je-Chul
authors.initials: JC
authors.lastname: Lee
authors.forename: Sung-Yong
authors.initials: SY
authors.lastname: Seol
authors.forename: Yu-Chul
authors.initials: YC
authors.lastname: Lee
authors.forename: Dong-Taek
authors.initials: DT
authors.lastname: Cho
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000378:metabolism; D024901:Drug Resistance, Multiple, Bacterial; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology; D006785:Hospitals, University; D006801:Humans; D007710:Klebsiella Infections / Q000453:epidemiology / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000201:enzymology*; D007723:Korea / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D010957:Plasmids; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C107198:beta-lactamase SHV-12; C048795:AmpC beta-lactamases; D001618:beta-Lactamases