A second case of multidrug-resistant Mycobacterium leprae isolated from a Japanese patient with relapsed lepromatous leprosy.

Emergence of drug resistant strains of Mycobacterium leprae was reported soon after the introduction of dapsone (diamino-diphenyl sulphone, DDS) for leprosy treatment (6, 10, 11). Three cases of multidrug-resistant strains of M. leprae have been reported recently (2, 8, 9, 13). In order to prevent multiple drug resistant strains of M. leprae from developing, current leprosy control strategies are based on early detection of cases and treatment with multidrug therapy (MDT) as recommended by the World Health Organization (WHO). We report here the identification of a multidrug-resistant strain of M. leprae from a patient who received inadequate therapy for leprosy. The drug resistant profile of the isolated strain was confirmed by the mouse footpad method and the identification of mutations in genes previously shown to be associated with resistance to each drug was made.