Determination of the MIC and MBC of Chitosan from Cockroach and Cricket Against Some Bacterial Isolates

摘要

To determine the Minimum Inhibitory Concentration and Minimum Bactericidal Concentration of chitosan from cockroach and cricket against bacterial isolates, Staphylococccus aureus, Staphylococcus epidermidis, Klebsiella pneumoniae, Streptococcus pyogenes, Bacillus subtilis and Pseudomonas aeruginosa. The antimicrobial efficacy of chitosan was determined by the standard method of Clinical and Laboratory Standards Institute (CLSI). Different concentrations were prepared and the MICs were calculated by tube dilution method in triplicates. The MBCs were determined by the lowest concentration that kills 99.9 of the initial bacterial population. The data generated were analyzed by ANOVA and Turkeys post hoc test using spss soft ware. The MIC of cockroach chitosan against S. aureus, B. subtilis, K. pneumoniae, S. pyogenes, P. aeruginosa and S. epidermidis, were found to be 240, 220, 0, 260, 240 and 0mg/ml while the MIC of cricket chitosan against the organisms were found to be 240,240,240,0, 220 and 280mg/ml. The MBC of chitosan from cockroach against the organisms were found to be 260, 260, 0, 280, 260 and 0 mg/ml while that of cricket were found to be 240, 240, 280, 0, 240 and 300 mg/ml. This study revealed that chitosan from P. Americana and A. domestica can be used as disinfectants in wounds, since they act against S. aureus, B. subtilis, K. pneumoniae, S. pyogenes, P. aeruginosa and S. epidermidis which are organisms commonly found in wound.