Korean Lepr Bull.  2023 Dec;56(2):2.

Antibacterial Activity of New Tuberculosis Drugs against Mycobacterium leprae

• Cho SN

Abstract

World Health Organization recently recommended new drug regimens including bedaquiline, pretomanid, and linezolid for the treatment of quinolone-resistant multidrug tuberculosis (pre-XDR-TB). Considering a continuous increase in rifampin- and ofloxacin-resistant Mycobacterium leprae, of interest would be antibacterial activities of the new TB drugs against M. leprae. Of the three new TB drugs above, bedaquiline showed the most potent bactericidal effects even after a single dose of 25 mg/km in the mouse footpad infection model of M. leprae. Bedaquiline level could be lowered to as low as 0.1 mg/kg when given with rifampin and/or clofazimine in a combination treatment in mouse models. Despite very potent anti-M. tuberculosis activity, however, pretomanid showed a moderate inhibitory activity against M. leprae in mouse model because of natural resistance due to lack of niroreductase enzyme in the organism, which is essential in releasing nitric oxide. Although linezolid showed an antibacterial activity at 100 mg/kg concentration against M. leprae in a mouse model, it may not be feasible to use for treatment of Hansen’s Disease due to the high frequency of severe adverse events that appeared during treatment of TB patients. While waiting for more new TB drugs with anti-M. leprae activity, bedaquiline seems to be promising for use in the treatment of Hansen’s Disease in the near future.

Keyword

Tuberculosis Drugs; Mycobacterium leprae