Antibiotic resistance pattern and distribution of Vietnamese extended-spectrum- β lactamase (VEB-1) gene in Acinetobacter baumannii isolated from hospitalized patients in Kashan Shahid Beheshti hospital during 2013-2014

Acinetobacter baumannii are widely distributed pathogens in hospitals. They have the ability to have various mechanisms of resistance. Multiple drug resistant (MDR) strains of A. baumannii have created therapeutic problems worldwide. The aim of the present study was to determine the antimicrobial susceptibility and detection of blaOXA51 and VEB-1 genes of A. baumannii isolated from clinical specimens in teaching hospital.
A descriptive cross-sectional study was performed on 124 A. baumannii strains isolated from patients in Beheshti hospital, Kashan, Iran, during 2013-2014. At the species level, the isolates were identified by conventional biochemical tests and then confirmed by the Microgen kit (GNA). An antibiotic susceptibility test was performed for 17 antimicrobial agents according to the CLSI guidelines. Multiple drug resistant was defined as presence of resistance to three or more classes of antibiotics. The presence of blaOXA51 and VEB-1 genes was investigated using the polymerase chain reation.
Acinetobacter baumannii isolates demonstrated the highest resistance to ceftriaxone, ceftazidime and cefotaxime. All isolates were sensitive to colistin and polymyxin. All isolates were positive for blaOXA51. Thirty-two isolates (25.8%) were positive for the VEB-1 gene.
This study highlights the high frequency of MDR isolates. The VEB-1 gene, which produces extended spectrum beta lactamase enzymes and inactivates third generation cephalosporins, was positive in more than 25% of the samples.