Abstract:

Objective To detect gene mutations associated with dapsone-, rifampicin- and ofloxacin-resistance in lesions of patients with recurring or treatment-resistant leprosy collected from 2010 to 2011. Methods Clinical data and lesional specimens were collected during 2010-2011 from patients with recurring or treatment-resistant leprosy who were diagnosed and reported by provincial centers for leprosy control. Mycobacterium leprae DNA was extracted from the specimens and subjected to PCR for the amplification of folP1, rpoB and gyrA genes. The PCR products were directly sequenced and BLAST program was used to compare the sequence of isolated strains with the reference sequence in GenBank. Results Twenty-four patients were enrolled in this study, including 13 with recurring leprosy and 11 with treatment-resistant leprosy. Twenty-one patients showed positive PCR results in all the three regions. Of these PCR-positive specimens, 3 from 1 patient with recurring and 2 patients with resistant leprosy harbored a point mutation, acc （threonine）→ gcc （alanine）, at codon 53 in the floP1 gene, 1 from a patient with recurring leprosy harbored a missense mutation, gat （aspartic acid） → aac （asparagine）, at codon 441 in the rpoB gene. Conclusions Mutations are detected in the folP1 and rpoB genes, which are associated with the resistance to dapsone and rifampicin respectively, but not in the ofloxacin resistance-associated gyrA gene, in Mycobacterium leprae isolates from patients with recurring or treatment-resistant leprosy.

Key words: Therapy resistant