In Vitro Synergy of Fusidic Acid and Amikacin against Methicillin Resistant Staphlococus Aureus

Objective: To test in vitro combination of fusidic acid and amikacin against infections caused by methicillin resistant Staphlococus aureus (MRSA). Methodology: In vitro study conducted in Department of Pharmacology and Microbiology, Dr. Ziauddin Medical University. The duration of study was March 2004February 2005. Antibiotic susceptibility testing was done by Kirby Bauer’s disc diffusion method and by minimum inhibitory concentration (MIC) by broth macrodilution and checkerboard technique for synergy. FIC (fractional inhibitory concentrations) were calculated. Results: MIC of fusidic acid was 0.03-1μg/ml and amikacin 0.5-16μg/ml respectively. The combination of these demonstrated synergy. Evidence of synergy correlated directly with the MICs of fusidic acid and amikacin. Conclusion: Combination therapy with fusidic acid and amikacin may be a reasonable alternative in the treatment of infections caused by MRSA isolates and encourages clinical evaluation.