SNP Typing of Mycobacterium leprae Clinical Strains in Côte d'Ivoire Reveals Genotype 4 Circulating

Despite years of chemotherapy and the consequent reduction in the prevalence of leprosy in Cote d'Ivoire, there are still high levels of new detection cases. Thus the slow onset of leprosy and the reliance on physical examination for detection of the disease have limited the epidemiological follow-up necessary to understand and control transmission. The differentiation of isolates of Mycobacterium leprae, the causative organism of leprosy, has not yet been established in Cote d'Ivoire. Three SNP loci have been found informative and have been used to understand the evolution and global spread of M. leprae. Based on these reports and the availability of the whole genome sequence, a SNP analysis for strain typing has been realized. This preliminary study present the results of the M. leprae genotype study circulating in Cote d'Ivoire. For each clinically confirmed case of multibacillary leprosy (new cases or relapses), a sample of dermal juice was examined after Ziehl-Neelsen staining and a specific PCR targeting the RLEP repeat sequence. 31 isolates were used to search for single nucleotide polymorphism (SNP) present in the M. leprae genome at positions 14676, 1642875 and 2935685, then determined after sequencing of the mutation zones. The SNPs were determined with a yield of 44,92% (31/69). Genotype 4 was the only genotype founded from the 31 strains identified. This genotype corresponds to those previously reported as widespread in West African countries including Cote d'Ivoire.