title: Occurrence of blaOXA-23 gene in imipenem-susceptible Acinetobacter baumannii.
abstract: The aim of the current study was to describe the occurrence of the blaOXA-23 gene and the ISAba1 element in imipenem-susceptible Acinetobacter baumannii strains. By performing the polymerase chain reaction mapping using combinations of ISAba1 forward primers and the blaOXA-23-like gene reverse primers, we demonstrated that the ISAba1 element did not occur upstream of the blaOXA-23 gene in five of 31 isolates, which explained the lack of resistance to imipenem despite the presence of the blaOXA-23 gene. All of the blaOXA-23-positive isolates were susceptible to imipenem and meropenem with minimal inhibitory concentration ≤ 4 µg/mL. Pulsed-field gel electrophoresis analysis revealed four genotypes among the five blaOXA-23-positive isolates. The current report of the blaOXA-23 gene in imipenem-susceptible isolates provided evidence that this gene may be silently spread in a hospital environment and highlighted the threat of undetected reservoirs of carbapenemase genes.
authors: Laboratório de Pesquisa em Infecção Hospitalar, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, RJ, Brasil. karynerc@ioc.fiocruz.br
authors: Karyne Rangel
authors: KR
authors: Carvalho
authors: Ana Paula D'Alincourt
authors: AP
authors: Carvalho-Assef
authors: Lia Galvão dos
authors: LG
authors: Santos
authors: Maria José Félix
authors: MJ
authors: Pereira
authors: Marise Dutra
authors: MD
authors: Asensi
mesh_terms: D040981:Acinetobacter baumannii / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D052978:Disk Diffusion Antimicrobial Tests; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D015378:Imipenem / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D015378:Imipenem; C466679:beta-lactamase OXA-23; D001618:beta-Lactamases