Resistance pattern of different aminoglycosides against Gram positive and Gram negative clinical isolates of Karachi.

Microbial resistance to majority of the available antimicrobial agent is a serious and global problem. Due to heavy and discriminate usage of antibiotics, high prevalence of drug-resistant bacteria in the indigenous fecal flora, poor standards of sanitation, lack of education and prevalence of malnutrition. This problem is at its extreme in developing countries like Pakistan. For this various Aminoglycosides were tested against different Gram positive and Gram negative isolates. The results showed that these isolates were resistant against most of these antibiotics with increase in MIC's. In Aminoglycoside group Tobramycin was the most effective agent against Staph. aureus and E. coli with MIC90s of 1 microg/ml and 2 microg/ml, while against Klebsiella and P. aeruginosa its activity was moderate to low. Amikacin showed highest activity against P. aeruginosa, E. coli and Klebsiella species with MIC90s of 4 microg/ml and 8 microg/ml. Kanamycin and Streptomycin were not active against the tested isolates.