Abstract

Aminoglycosides still play an important role in antistaphylococcal therapies, although emerging resistance amongst staphylococci is widespread. The objective of the present study was to know the percentage of aminoglycoside resistance among Staphylococcus aureus isolates. A total of 250 isolates of S. aureus were studied from different clinical specimens like blood, pus, wound swabs, sputum, ear swabs and body fluids. All the isolates were tested for their susceptibility to four aminoglycosides namely gentamicin, amikacin, tobramycin and netilmicin by Kirby Bauer disc diffusion method using criteria of standard zone of inhibition. Methicillin resistant S. aureus (MRSA) detection was done by cefoxitin disc diffusion method. Out of the 250 S. aureus isolates, 66 (26.4%) isolates demonstrated resistance to at least one of the four aminoglycosides tested. Four isolates were resistant to all the four aminoglycosides tested. All these four were MRSA. The most active antimicrobial agent against S. aureus was found to be netilmicin followed by amikacin. Continued surveillance at both the genotypic and phenotypic levels as well as adherence to well-designed antibiotic and infection control policies are necessary to understand and limit further rise of resistant isolates.

Key words: Aminoglycosides, Staphylococcus aureus.