In vitro susceptibility of Mycobacterium tuberculosis to trimethoprim and sulfonamides in France.

Five type strains and 55 Mycobacterium tuberculosis complex clinical isolates were found resistant to trimethoprim with a MIC of >200 mg/liter and susceptible to both sulfadiazine and cotrimoxazole with a MIC90 of 10 mg/liter. Two M. canettii isolates uniquely yielded silent mutations C156 → T and G238 → C in the folP1 gene. Combined with scarce published data, these data indicate that sulfamides could be considered alternative antituberculous antibiotics.