Background and purpose: Aminoglycosides are broad-spectrum antibiotics that are often used in combination with other antibiotics for the treatment of severe S. aureus infections. This research aimed at investigating the phenotypic and genotypic evaluation of aminoglycoside resistance in clinical isolates of MRSA in Kerman, Iran.
Materials and methods: During a one year period, a total of 57 MRSA isolates was collected from 130 isolates of S. aureus. MRSA isolates were tested for susceptibility to 13 antimicrobial agents using disc diffusion method. Then, the presence of aminoglycoside modifying enzymes (AMEs) was evaluated by multiplex polymerase chain reaction.
Results: In the MRSA isolates, high resistance rates were observed for tetracycline, erythromycin, kanamycin and gentamicin. In fact, 73.7% and 68.4% of the isolates were found to be resistant to kanamycin and gentamicin, respectively. aac(6′)-Ie-aph(2″), aph(3′)-III, ant(4′)-Ia, and aph(2ʹʹ)-Id genes were detected in 40.3%, 15.7%, 12.2%, and 3.5% of the aminoglycosides–resistant isolates, respectively.
Conclusion: The prevalence of aminoglycosides resistance among MRSA isolates is rising, therefore, identification of resistance genes in order to achieve the exact pattern of resistance is helpful in preventing the spread of resistant strains.