title: CTX-M-14 and CTX-M-15 enzymes are the dominant type of extended-spectrum beta-lactamase in clinical isolates of Escherichia coli from Korea.
abstract: This study was performed to assess the prevalence and genotypes of plasmid-borne extended-spectrum beta-lactamases (ESBLs) and AmpC beta-lactamases in Escherichia coli in Korea. A total of 576 isolates of E. coli was collected from 12 Korean hospitals during May and July 2007. A phenotypic confirmatory test detected ESBLs in 82 (14.2 %) of the 576 E. coli isolates. The most common types of ESBLs identified were CTX-M-14 (n=32) and CTX-M-15 (n=27). The prevalence and diversity of the CTX-M mutants, including CTX-M-15, CTX-M-27 and CTX-M-57, with significant hydrolytic activity against ceftazidime were increased. PCR experiments detected genes encoding plasmid-borne AmpC beta-lactamases in 15/56 cefoxitin-intermediate or cefoxitin-resistant isolates, and the most common type of AmpC beta-lactamase identified was DHA-1 (n=10). These data suggest that the incidence of ESBLs in E. coli has increased as a result of the dissemination of CTX-M enzymes in Korea. In addition, CTX-M-22, CTX-M-27 and CTX-M-57 have appeared in Korea.
authors.affiliation: Department of Laboratory Medicine, Hallym University College of Medicine, 150-950, 948-1 Daerim 1-Dong, Youngdeungpo-Gu, Seoul, Republic of Korea.
authors.forename: Wonkeun
authors.initials: W
authors.lastname: Song
authors.affiliation: Department of Laboratory Medicine, Kwandong University College of Medicine, 697-24 Whajung-Dong, Dukyang-Gu, Goyang, Republic of Korea.
authors.forename: Hyukmin
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, 120-752, 134 Shinchon-Dong, Seodaemu-Gu, Seoul, Republic of Korea.
authors.forename: Kyungwon
authors.initials: K
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, 120-752, 134 Shinchon-Dong, Seodaemu-Gu, Seoul, Republic of Korea.
authors.forename: Seok Hoon
authors.initials: SH
authors.lastname: Jeong
authors.affiliation: Research Institute for Antimicrobial Resistance, Kosin University College of Medicine, 602-030, 34 Amnam-Dong, Suh-Gu, Busan, Republic of Korea.
authors.forename: Il Kwon
authors.initials: IK
authors.lastname: Bae
authors.affiliation: Department of Laboratory Medicine, Hallym University College of Medicine, 134-701, 150 Sungnae-Gil, Kangdong-Gu, Seoul, Republic of Korea.
authors.forename: Jae-Seok
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Center for Food Safety Evaluation, Korea Food and Drug Administration, 122-704, 231 Jinheung-Ro, Eunpyung-Gu, Seoul, Republic of Korea.
authors.forename: Hyo-Sun
authors.initials: HS
authors.lastname: Kwak
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology*; D029968:Escherichia coli Proteins / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D007723:Korea; D008826:Microbial Sensitivity Tests / Q000379:methods; D016133:Polymerase Chain Reaction / Q000379:methods; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000145:classification / Q000235:genetics*; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D047090:beta-Lactams; D001618:beta-Lactamases