Assessing capreomycin resistance on tlyA deficient and point mutation (G695A) Mycobacterium tuberculosis strains...

Capreomycin (CAP), a cyclic peptide antibiotic, is considered to be an ideal second-line drug for tuberculosis (TB). However, in the past few years, the emergence of more CAP-resistant (CAP^r) TB patients has limited its use. Although it has been reported that CAP resistance to Mycobacterium tuberculosis (Mtb) is associated with rrs or tlyA mutation, the exact mechanism of CAP^r Mtb strains, especially the mechanism associated with tlyA deficient or mutation, is not fully understood. Herein, we utilized a multi-omics (genome, proteome, and metabolome) approach to assess CAP resistance on tlyA deficient CAP^r Mtb strains (CAP^r1) and tlyA point mutation CAP^r Mtb strains (CAP^r2) that we established for the first time in vitro to investigate the CAP-resistant mechanism. Our results showed that the CAP^r1 strains (> 40 μg/ml) was more resistant to CAP than the CAP^r2 strains (G695A, 10 μg/ml). Furthermore, multi-omics analysis indicated that the CAP^r1 strains exhibited greater drug tolerance than the CAP^r2 strains may be associated with the weakening of S-adenosyl-L-methionine-dependent methyltransferase (AdoMet-MT) activity and abnormal membrane lipid metabolism such as suppression of fatty acid metabolism, promotion of glycolipid phospholipid and glycerolipid metabolism. As a result, these studies reveal a new mechanism for CAP resistance to tlyA deficient or mutation Mtb strains, and may be helpful in developing new therapeutic approaches to prevent Mtb resistance to CAP.