Antimicrobial resistance patterns and frequency of extended-spectrum beta-lactamase genes among Acinetobacter baumannii

Acinetobacter baumannii is an opportunistic pathogen that is resistant to many antibiotics including beta-lactams. production of β-lactamases is the main mechanism of β-lactam resistance in A. baumannii. The aim of the present study was to determine the antimicrobial susceptibility profile and frequency of ESBL genes in clinical isolates of A. baumannii in hospitals in Kerman, Iran.
In this cross-sectional study 102 isolates of Acinetobacter species were collected from clinical specimens, including, respiratory secretions, urine, blood culture and body fluid. For confirming A. baumannii Polymerase chain reaction (PCR) was used to identify blaOXA-51 gene. Antimicrobial susceptibility test was performed using the disk diffusion method. PCR technique was carried out for the detection of blaCTX-M, blaSHV, blaTEM, blaPER and blaVEB genes.
FINDINGS: blaOXA-51 gene was detected in 95 (93/1%) isolates. All of the isolates were resistant to cefepime and cefotaxime. Almost all of them were resistant to imipenem, meropenem, gentamicin, amikacin, aztreonam, ciprofloxacin, ceftazidim, levofloxacin, tetracycline and piperacillin-tazobactam. The rates of susceptibility to polymyxin-B and tigecycline were 61/1% and 23/2% respectively. The frequency of, blaSHV, blaTEM, blaCTX-M and blaVEB genes were 44 (46.3%), 30 (31.6%), 30 (31.6%), and 13 (13.7%) respectively. None of the isolates were carried blaPER gene.
because of the high rate of ESBLs producing A. baumannii isolates detected in this study, effective infection control strategy should be performed