Mutación en el gen gyrA de aislamientos hospitalarios de Acinetobacter baumannii en Montería, Colombia

Abstract

ObjectiveDetermine mutations in the gyrA gene associated to resistance to fluoroquinolones in A. baumannii. Materials and methodsFrom August, 2005 to February, 2007, 23 A. baumannii isolates were collected in a third level private clinic in Monteria. Research on gyrA, parC and AdeB genes was carried out, and the latter encodes for the efflux pump. DNA sequencing was performed, and the GenBank database and BLASTX search engine were used for sequence analysis. ResultsAmplification of the gyrA gene in A. baumannii isolates generated a 343pb fragment which presented loss of restriction site with the enzyme HinfI in 12/23 (52.1%) of the isolates resistant to fluoroquinolones. The fragment sequencing showed mutation characterized by the change of Ser-83 to Leu GenBank acces code EU886740. None of the isolates showed mutations in the parC gene or presence of the AdeB efflux pump. ConclusionThe A. baumannii isolates resistant to fluoroquinolones suggest that mutation of the gyrA gene encoding the serine amino acid change to leucine at codon 83 of these isolates is responsible or at least contributes to the mentioned resistance to fluoroquinolones.