ANTI MRSA AND ANTITUBERCULAR ACTIVITY OF PHENOXAZINONE CONTAINING MOLECULE FROM BORRA CAVES STREPTOMYCES SP. BCA1

An attempt was made to study the anti MRSA and antitubercularactivity of Streptomyces sp. BCA1 isolated from Borra Caves soil. In agar plug method, strain BCA1 showed 12-17 mm inhibition against Gram positive and Gram negative bacteria, including MRSA. Crude pigment produced from strain BCA1 by agar surface fermentation showed 15 – 17 mm inhibition in disc diffusion method against bacterial pathogens. In luciferase reporter phage (LRP) assay the crude pigment showed more than 80% reduction against standard strain M. tuberculosis H37Rv, drug sensitive and multi drug resistant (MDR) clinical isolates of M. tuberculosis. Active pigment was separated by TLC and its activity was confirmed by bioassay guided fractionation. The MIC value of the purified pigment against bacterial pathogens ranged between 6.25 and 50µg/ml. MIC value for M. tuberculosis H37Rv and drug sensitive clinical isolate was found to be 6.25 µg/ ml while that of MDR M. tuberculosis isolate was 25 µg/ ml. The solubility of purified pigment in acid and alkali as well as the appearance of absorption peak at 440 nm in UV spectral analysis revealed that the active pigment contains the phenoxazinone chromophore. Strain BCA1 was found to produce pigment and exhibited bioactivity even when grown at a low nutrient concentration (1/10X) YEME agar. This study, for the first time, reported an antitubercular pigment from actinobacteria isolated from Indian Caves