title: Increasing carbapenem resistance due to the clonal dissemination of oxacillinase (OXA-23 and OXA-58)-producing Acinetobacter baumannii: report from the Turkish SENTRY Program sites.
abstract: A significant increase in carbapenem-resistance rates among Acinetobacter baumannii isolates collected in two Turkish medical centres was detected in the 2000-2006 period (20-60 %) by the SENTRY Antimicrobial Surveillance Program. Carbapenem-resistant strains from 2006 were evaluated for the presence of encoding genes and epidemic clonality. OXA-58-like and OXA-23-like carbapenemase-producing strains were detected in both medical institutions. Seventeen out of 18 strains from Ankara were positive for blaOXA-58 primers and belonged to the same clone, whilst 26 isolates (25 from Istanbul and one from Ankara) harboured blaOXA-23-like genes and showed identical or similar PFGE patterns. Isolates producing OXA-23-like carbapenemases were more resistant than OXA-58-like carbapenemase producers to non-carbapenem antimicrobial agents. Carbapenem resistance in these institutions was observed to be largely driven by the dissemination of clones producing OXA-type carbapenemases.
authors.affiliation: Hacettepe University, Children's Hospital, Ankara, Turkey.
authors.forename: Deniz
authors.initials: D
authors.lastname: Gur
authors.affiliation: Marmara University Hospital, Istanbul, Turkey.
authors.forename: Volken
authors.initials: V
authors.lastname: Korten
authors.affiliation: Hacettepe University, School of Medicine, Infectious Disease Unit, Ankara, Turkey.
authors.forename: Serhat
authors.initials: S
authors.lastname: Unal
authors.affiliation: JMI Laboratories, North Liberty, IA 52317, USA.
authors.forename: Lalitagauri M
authors.initials: LM
authors.lastname: Deshpande
authors.affiliation: JMI Laboratories, North Liberty, IA 52317, USA.
authors.forename: Mariana
authors.initials: M
authors.lastname: Castanheira
mesh_terms: D000151:Acinetobacter Infections / Q000453:epidemiology* / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000145:classification / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015780:Carbapenems / Q000494:pharmacology*; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D017720:Molecular Epidemiology; D018571:Sentinel Surveillance; D014421:Turkey / Q000453:epidemiology; D018440:beta-Lactam Resistance / Q000235:genetics; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; D001618:beta-Lactamases; C108449:oxacillinase