Genotypic characterization of Mycobacterium leprae strains resistant to rifampicin and ofloxacin in three health districts in Chad

Abstract

Antimicrobial surveillance and identification of the genetic basis of antimicrobial resistance provides important information to optimize patient care. The present study was an analytical cross-sectional study aimed at determining the prevalence of rifampicin and ofloxacin resistance genes among Mycobacterium leprae strains in three health districts in Chad.
 The determination of the folP1, rpoB and gyrA resistance genes was carried out by PCR-RLEP and confirmed by sequencing from 80 biopsy samples taken from patients with multibacillary leprosy, including 12 relapsed patients and 68 new cases. In the whole cohort, 1/80 (1.2%) showed resistance to rifampicin and 1/80 (1.2%) to ofloxacin. No mutations were detected for dapsone. The presence of M. leprae mutation associated with rifampicin resistance was observed in a relapsed patient and the mutation associated with ofloxacin resistance was observed in a patient with multibacillary leprosy who had not been sensitized by ofloxacin but should have used other quinolones. Both mutant strains revealed the emergence of secondary resistance.
 This study, the first to highlight the emergence of resistance to rifampicin and ofloxacin in Chad. It raises the need to implement a robust surveillance system to detect resistance of Mycobacterium leprae in Chad and even in Central Africa.
 Keywords: Mycobacterium leprae, resistance, Chad