Study on Efflux Pump Inhibition Activity of Marine Actinomycetes against Oflaxcin Resistsnt M. tuberculosis

Abstract

Studies were conducted to isolate marine actinomycetes active against oflaxcin resistant M. tuberculosis. Out of 25 actinomycetes isolates designated as ECRMP 4 showed potent antimycobacterial activity against all three tested Mycobacterial strains. Representative bioactive isolate was characterized using phenotypic property and identified as Micropolyspora sp. The zone of inhibition was 20 ± 0.1 mm (62% RIZD) against M. tuberculosis and 18 ± 0.6 mm (100% RIZD) against OFL^R M. tuberculosis. The bioassay of crude compound prevails that the R_f value of compound is 0.16. In this study we evaluated the role of the efflux pumps in quinolone resistance by using carbonyl cyanide m-chlorophenyl hydrazone (CCCP), 2,4-dinitrophenol (DNP) and verapamil against clinical isolate of M. tuberculosis. The MIC levels of OFL showed twofold reductions in presence of CCCP, verapamil and DNP while in case of ECRMP 4 Micropolyspora sp. metabolite showed fourfold reductions in MIC. These finding suggest the involvement of active efflux pumps activity of isolated compound from Micropolyspora can be able to produce noval antimycobacterial molecules.

Keywords: Micropolyspora, oflaxcin, relative zone of inhibition, efflux pump