title: [Dissemination of IMP-1 and OXA type beta-lactamase in carbapenem-resistant Acinetobacter baumannii].
abstract: BACKGROUND
  Acinetobacter baumannii is an aerobic, gram-negative, glucose-nonfermenting bacterium, which has emerged as a serious opportunistic pathogen. In recent years, the increasing instance of carbapenem-resistant A. baumannii producing metallo-beta-lactamases (MBLs) or OXAtype beta-lactamases is causing a serious clinical problem. In this study, we investigated the prevalence of Ambler class A, B, and D beta-lactamases and their extended-spectrum derivatives in carbapenem-resistant A. baumannii isolates.
  
  
  METHODS
  A total of 31 consecutive, non-duplicate, carbapenem-resistant A. baumannii were isolated from three university hospitals in the Chungcheong province of Korea. The modified Hodge and inhibitor-potentiated disk diffusion tests were conducted for the screening of carbapenemase and MBL production, respectively. PCR and DNA sequencing were performed for the detection of beta-lactamase genes. We also employed the enterobacterial repetitive intergenic consensus (ERIC)-PCR method for the epidemiologic study.
  
  
  RESULTS
  Twenty-three of 31 isolates harbored bla(OXA-2)(51.6%), bla(OXA-23)(22.6%), bla(IMP-1)(48.4%),and bla(VIM-2)(3.2%). All of the OXA-2-producing strains also evidenced MBLs. The strains that harbored bla(OXA-23)were isolated only in hospital C, and only in a limited fashion. The ERIC-PCR pattern of the five OXA-23 strains indicated that the isolates were closely related in terms of clonality. The six strains producing IMP-1 isolated from hospital A were confirmed to be identical strains.
  
  
  CONCLUSIONS
  A. baumannii strains harboring IMP-1 or OXA-type beta-lactamases are currently widely distributed throughout the Chungcheong province of Korea. The most notable finding in this study was that a bla(OXA-2)-producing A. baumannii harboring MBL, which has not been previously reported, can also lead to outbreaks.
authors.affiliation: Department of Laboratory Medicine, Chungnam National University Hospital, Daejeon, Korea.
authors.forename: Ji Youn
authors.initials: JY
authors.lastname: Sung
authors.forename: Kye Chul
authors.initials: KC
authors.lastname: Kwon
authors.forename: Jong Woo
authors.initials: JW
authors.lastname: Park
authors.forename: Yeon Suk
authors.initials: YS
authors.lastname: Kim
authors.forename: Ji Myung
authors.initials: JM
authors.lastname: Kim
authors.forename: Kyeong Seob
authors.initials: KS
authors.lastname: Shin
authors.forename: Jong Wan
authors.initials: JW
authors.lastname: Kim
authors.forename: Chi Seon
authors.initials: CS
authors.lastname: Ko
authors.forename: So Youn
authors.initials: SY
authors.lastname: Shin
authors.forename: Jeong Hoon
authors.initials: JH
authors.lastname: Song
authors.forename: Sun Hoe
authors.initials: SH
authors.lastname: Koo
mesh_terms: D000151:Acinetobacter Infections / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015780:Carbapenems / Q000494:pharmacology*; D052978:Disk Diffusion Antimicrobial Tests; D024901:Drug Resistance, Multiple, Bacterial; D006801:Humans; D016133:Polymerase Chain Reaction; D001618:beta-Lactamases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; C409201:beta-lactamase IMP-1; C039404:beta-lactamase OXA-2; D001618:beta-Lactamases