Determination of MIC and MBC of selected azithromycin capsule commercially available in Bangladesh

Background: Usually we consider that the tetracycline capsules in Bangladesh maintain standard MIC and MBC. But how much is this assumption is true? this will be evaluated through this research work. Objective: This is a cross sectional study (January-2006 to Decmber-2006) to determine the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of tetracycline capsule commercially available in Bangladesh. Method: The collected samples were analyzed according to BP specifications. The MIC was determined by broth dilution method. MBC were determined by the drop plate method from the tubes, where apparently no visible growth found. Results: The MIC value of tetracycline capsule against Bacillus pumillus, Pseudomonus spp. Staphylococcus aureus, Shigella spp. and E coli were found 1.0, 8.0, 0.5, 1.0 and > 64.0 µg/ml (micro gram per milliliter) respectively. The MBC value of tetracycline capsule against Bacillus pumillus, Pseudomonus spp. Staphylococcus aureus, Shigella spp. and E coli were found 2.0, 16.0, 1.0, 2.0 and > 64.0 µg/ml respectively. Conclusion: MIC and MBC values higher than that of the peak serum concentration must have chance of therapeutic failure and development of antibiotic tolerance and resistance to the bacteria.