The potential of azole antifungals against latent/persistent tuberculosis.

The aim of the present study was to evaluate the chemotherapeutic potential of econazole against latent tuberculosis. The activity of econazole and clotrimazole was tested against the latent bacilli (Mycobacterium tuberculosis H(37)Rv) developed by nutrient starvation under in vitro conditions and by drugs under in vivo conditions. The latent bacteria developed under in vitro latent conditions were acid-fast negative, nonreplicating, resistant to conventional antitubercular drugs and showed low respiration rates. Econazole as well as clotrimazole were found to have strong antimycobacterial potential against latent Mycobacterium tuberculosis under in vitro conditions as seen by reductions in colony-forming units. Further, econazole prevented the formation of drug-induced latency and significantly reduced bacterial burden from lungs and spleens of latent tuberculosis-infected mice. We conclude that azole drugs bear significant therapeutic potential against latent tuberculosis.