Fig. 5: In vitro assay for the development of resistance in MRSA towards 6c.

a The development of resistance in serial passage of MRSA with repeated exposure of ofloxacin, vancomycin, and 6c over 56 days. The initial MIC values of 8 μg/mL, 1 μg/mL, and 2.5 μg/mL, were used for ofloxacin, vancomycin, and 6c, respectively. This assay was repeated three times independently yielding similar results. b MIC values of 6c against MRSA that become resistant to ofloxacin (mutant MRSAoflR) and vancomycin (mutant MRSAvanR). c A schematic on the modes of antimicrobial actions of 6c against MRSA.