Depletion of resuscitation-promoting factors has limited impact on the drug susceptibility of Mycobacterium tuberculosis.
OBJECTIVE
Mycobacterium tuberculosis has five homologues of the muralytic resuscitation-promoting factor (Rpf), which are collectively dispensable for growth in vitro, but are required for resuscitation from a non-culturable state and for virulence in a mouse infection model. Our study was aimed at assessing the drug susceptibility of mutants lacking all five rpf genes.


METHODS
Drug susceptibility was determined in liquid medium using the broth microdilution method.


RESULTS
Strains of M. tuberculosis that lack all five rpf-like genes display a 4-8-fold increase in susceptibility to vancomycin and erythromycin, but show no significant difference in susceptibility to other antibiotics tested, including first- and second-line antitubercular agents.


CONCLUSIONS
These results suggest that the possible alterations in the peptidoglycan structure and/or turnover caused by Rpf deficiency have a limited impact on the drug susceptibility of M. tuberculosis.
Kana
Bavesh D
BD
MRC/NHLS/WITS Molecular Mycobacteriology Research Unit, DST/NRF Centre of Excellence for Biomedical TB Research, University of the Witwatersrand, National Health Laboratory Service, Johannesburg 2000, South Africa. bavesh.kana@nhls.ac.za
Mizrahi
Valerie
V
Gordhan
Bhavna G
BG
D000995:Antitubercular Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D016207:Cytokines / Q000172:deficiency* / Q000235:genetics; D004917:Erythromycin / Q000494:pharmacology; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000235:genetics; D014640:Vancomycin / Q000494:pharmacology
D000995:Antitubercular Agents; D001426:Bacterial Proteins; D016207:Cytokines; C113704:resuscitation-promoting factor, bacteria; D004917:Erythromycin; D014640:Vancomycin