Molecular detection of mutations in the gyrA gene associated with fluoroquinolone resistance in Mycobacterium leprae strains from leprosy patients in Adzopé, Côte d’Ivoire

Objectives

Recommended control measures for leprosy treatment with multidrug therapy (MDT) aim to limit the spread of drug-resistant Mycobacterium leprae strains. However, fluoroquinolone resistance continues to be reported in several endemic countries. In Côte d’Ivoire, no study has yet evaluated M. leprae resistance to fluoroquinolones used in MDT. This study provides the first assessment of fluoroquinolone resistance in M. leprae isolates collected in Adzopé, Côte d’Ivoire.

Methods

For each clinically confirmed case of multibacillary leprosy (new cases and relapses), slit-skin smear samples were collected and analyzed by microscopic examination after Ziehl-Neelsen staining, as well as by PCR targeting the RLEP repeat sequence. A total of 69 isolates were tested for amplification of the gyrA gene, known to be involved in fluoroquinolone resistance. Mutations were identified by sequencing of the amplified regions using the ABI 3500 genetic analyzer.

Results

Among the 69 isolates analyzed, 9 (18.75%) harboured mutations conferring resistance to fluoroquinolones. The mutation detected was A91V (9.09%), which is known to be associated with fluoroquinolone resistance.

Conclusions

This study provides evidence of fluoroquinolone-resistant M. leprae strains in Côte d’Ivoire. These findings highlight the need for regular molecular surveillance to monitor the evolution of drug resistance and support the development of control strategies to limit the spread of resistant strains in endemic areas.