Efficacy of nitazoxanide against clinical isolates of Mycobacterium tuberculosis.

Nitazoxanide (NTZ) has bactericidal activity against the H37Rv laboratory strain of Mycobacterium tuberculosis with a MIC of 16 µg/ml. However, its efficacy against clinical isolates of M. tuberculosis has not been determined. We found that NTZ's MIC against 50 clinical isolates ranged from 12 to 28 µg/ml with a median of 16 µg/ml and was unaffected by resistance to first- or second-line antituberculosis drugs or a diversity of spoligotypes.