title: OXA- and GES-type β-lactamases predominate in extensively drug-resistant Acinetobacter baumannii isolates from a Turkish University Hospital.
abstract: We determined the antibiotic susceptibility and genetic mechanisms of resistance in clinical strains of Acinetobacter baumannii from Istanbul, Turkey. A total of 101 clinical strains were collected between November 2011 and July 2012. Antimicrobial susceptibility was performed using the Vitek 2 Compact system and E-test. Multiplex PCR was used for detecting bla(OXA -51-like), bla(OXA -23-like), bla(OXA -40-like) and bla(OXA -58-like) genes. ISAba1, bla(IMP -like), bla(VIM -like), bla(GES), bla(VEB), bla(PER -2), aac-3-Ia and aac-6'-Ib and NDM-1 genes were detected by PCR and sequencing. By multiplex PCR, all strains were positive for bla(OXA -51), 79 strains carried bla(OXA -23) and one strain carried bla(OXA -40). bla(OXA -51) and bla(OXA -23) were found together in 79 strains. ISAba1 element was detected in 81 strains, and in all cases it was found upstream of blaOXA -51 . GES-type carbapenemases were found in 24 strains (GES-11 in 16 strains and GES-22 in 8 strains) while bla(PER -2), bla(VEB -1), bla(NDM -1), blaIMP - and blaVIM -type carbapenemases were not observed. Aminoglycoside modifying enzyme (aac-3-Ia and aac-6'Ib) genes were detected in 13 and 15 strains, respectively. Ninety-seven (96%) A. baumannii strains were defined as MDR and of these, 98% were extensively drug resistant (sensitive only to colistin). Colistin remains the only active compound against all clinical strains. As seen in other regions, OXA-type carbapenemases, with or without an upstream ISAba1, predominate but GES-type carbapenemases also appear to have a significant presence. REP-PCR analysis was performed for molecular typing and all strains were collected into 12 different groups. To our knowledge, this is the first report of GES-11 and OXA-40 in A. baumannii from Turkey.
authors: Department of Medical Microbiology, Faculty of Medicine, Recep Tayyip Erdogan University, Rize, Turkey.
authors: A C
authors: AC
authors: Cicek
authors: A
authors: A
authors: Saral
authors: M
authors: M
authors: Iraz
authors: A
authors: A
authors: Ceylan
authors: A O
authors: AO
authors: Duzgun
authors: A Y
authors: AY
authors: Peleg
authors: C
authors: C
authors: Sandalli
mesh_terms: D040981:Acinetobacter baumannii / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D004251:DNA Transposable Elements; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D019450:Genes, MDR; D006785:Hospitals, University; D006801:Humans; D008826:Microbial Sensitivity Tests; D014421:Turkey; D018440:beta-Lactam Resistance / Q000235:genetics*; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004251:DNA Transposable Elements; C466679:beta-lactamase OXA-23; D001618:beta-Lactamases; C488541:beta-lactamase OXA-40, Acinetobacter baumannii; C577373:beta-lactamase OXA-51, Acinetobacter baumannii; C534889:beta-lactamase OXA-58, Acinetobacter baumannii; C063912:carbapenemase
keywords: Acinetobacter baumannii; GES-11; GES-22; OXA-40; antimicrobial agents