Occurrence of blaOXA-23 gene in imipenem-susceptible Acinetobacter baumannii

• Autor(a) principal: Carvalho,Karyne Rangel
• Data de Publicação: 2011
• Outros Autores: Carvalho-Assef,Ana Paula D'Alincourt, Santos,Lia Galvão dos, Pereira,Maria José Félix, Asensi,Marise Dutra
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Memórias do Instituto Oswaldo Cruz
• Texto Completo: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0074-02762011000400020
• topic: imipenem-susceptible; Acinetobacter baumannii; blaOXA-23

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.