Molecular Epidemiology of Aminoglycosides Resistance in Acinetobacter Spp. with Emergence of Multidrug-Resistant Strains

Background: acinetobacter spp. is characterized as an important nosocomial pathogen and increasing antimicrobial resistance.our aim was to evaluate antimicrobial susceptibility and aminoglycosides resistance genes of acinetobacter spp. isolatedfrom hospitalized patients.methods: sixty isolates were identified as acinetobacter species. the isolates were tested for antibiotic resistance by discdiffusion method for 12 antimicrobials. the presence of apha6, aacc1 aada1, and aadb genes were detected using pcr.results: from the isolated acinetobacter spp. the highest resistance rate showed against amikacin, tobramycin, and ceftazidim,respectively; while isolated bacteria were more sensitive to ampicillic/subactam. more than 66% of the isolateswere resistant to at least three classes of antibiotics, and 27.5% of mdr strains were resistant to all seven tested classes ofantimicrobials. the higher mdr rate presented in bacteria isolated from the icu and blood samples. more than 60% of themdr bacteria were resistance to amikacin, ceftazidim, ciprofloxacin, piperacillin/tazobactam, doxycycline, tobramycin andlevofloxacin. also, more than 60% of the isolates contained phosphotransferase apha6, and acetyltransferase genes aacc1,but adenylyltransferase genes aada1 (41.7%), and aadb (3.3%) were less prominent. 21.7% of the strains contain threeaminoglycoside resistance genes (apha6, aacc1 and aada1).conclusion: the rising trend of resistance to aminoglycosides poses an alarming threat to treatment of such infections. thefindings showed that clinical isolates of acinetobacter spp. in our hospital carrying various kinds of aminoglycoside resistancegenes.