Mycobacterium Tuberculosis Rv1473 is a Novel Macrolides ABC Efflux Pump Regulated by WhiB7

Aim: To characterize a novel macrolide ATP binding cassette efflux pump encoding gene Rv1473 which might be involved in antibiotic resistance. Methods: Mycobacterium smegmatis was used as a surrogate model for pathogenic mycobacteria, drug susceptibility assays and ethidium bromide accumulation assay were harnessed to verify drug resistance. The real-time quantitative PCR was used to evaluate the transcription levels of WhiB7 and Ms3140 upon exposure to macrolides. Results: Rv1473 contributes to macrolides resistance via efflux mechanisms, and was positively regulated by the transcription factor WhiB7 upon macrolides exposure. Conclusion: Rv1473 is a novel ATP binding cassette efflux pump involved in mycobacterium intrinsic antibiotics resistance via efflux mechanism. This finding will facilitate novel antibiotic discovery and the treatment of pathogen, especially for nontuberculous mycobacteria.