The investigation of resistance genes of carbapenem resistant Acinetobacter baumannii isolates with Pulsed Field Gel Electrophoresis

Acinetobacter is a pathogen which can cause seriousnosocomial outbreaks especially in intensive care units. Carbapenemases of OXA are the mostly cause of carbapenem resistance.OXA type enzymes divide into 4 subgroups. (OXA51, OXA24, OXA58, OXA23) OXA 51 subgroup of genes are intrinsic in Acinetobacter strains. Genes gained horizontally with mobile elements which codes the subgroup enzymes like OXA 58,23 and 24 can be together with OXA 51 gene.As being a transcriptional promotor ISAbaI; which localized at the upstream location of blaOXA 51 gene can induce beta-lactamase gene expression.In this work we aimed to investigate the subgroups of blaOXA genes with multiplex PCR, ISAbaI segment with in-house PCR and clonal relations of isolates with PFGE between carbapenem resistant A.baumanii strains isolated from nosocomial infections in our hospital.OXA-51 and ISAbaI genes identified from whole (%100) of the 55 isolates. We identified OXA 58, OXA 51 and ISAbaI genes in 4 of the isolates, OXA 24, 51 and ISAbaI genes in 3 of isolates but OXA 23 gene had been identified in none of the isolates. As a result of PFGE, 29 of 55 isolates found to be closely related and also thought to be in the same clone.Key Words: Acinetobacter baumannii, blaOXA21, blaOXA23, blaOXA51, blaOXA58, PFGE