[Drug resistance of multibacillary leprosy patients in Japan--results of molecular genetic analyses].

UNLABELLED: Gene mutation of Mycobacterium leprae was studied on bacilli-positive multibacillary leprosy patients since 2000 in Japan.

SUBJECTS: LL 31 cases, BL 7 cases.

RESULTS: gene mutation of folP was found in 19/36 cases (52.8%), that of rpoB in 13/33 cases (39.4%), that of gyrA in 6/31 cases (16.8%). Five cases showed both mutations of folP and rpoB, and one case showed those of fol/P and gyrA. Mutations of folP, rpoB andgyrA all were found in 4/36 cases (10.3%). High incidence of resistance to DDS or rifampicin was observed, and incidence of resistance to of loxacin was considerably high. These results reveal existence of multidrug-resistant bacilli in Japanese leprosy patients. Treatment of these cases was arranged according to the result of gene mutation analysis and satisfactory effects were obtained in 34/38 cases. One case did not response to newer treatment. Three cases refused use of improved treatment and their disease activities are not controlled. This study proved that gene mutation analysis is a rapid and accurate method to know the drug resistance against DDS, rifampicin and new quinolones, and important in chemotherapy of leprosy.