Mycobacterium leprae strains circulating in Colombia
Leprosy is a chronic infectious disease caused by Mycobacterium leprae (M. leprae) and M. lepromatosis that affects the skin, peripheral nerves and other organs or membranes. With 200,000 new cases reported around the world each year and an alarming 700 new cases detected every day, leprosy has unfortunately become as a global disease burden in the last decade. Moreover, there is a high prevalence of leprosy in tropical and subtropical regions, especially in developing countries. Thus, accurate detection, identification and typing of M. leprae are essential for epidemiological surveillance and to study population dynamics in relation to the origin and spread of disease. Therefore, this study was designed to investigate the genomic, phylogenetic, and geographic relationships between worldwide strains and South America M. leprae isolates, particularly those collected in Colombia. Whole genome sequencing was performed on 59 Colombian biopsies to reveal genetic diversity of Colombian strains through comparative genomics. The results showed that these strains clustered in the 3I genotype branch, which contained medieval European strains. Of note was the finding of an isolate with high homology to a colonizing strain (NHDP-63) of nine-banded armadillo. First reported case in South America. This zoonotic strain carried 39 missense mutations in 32 CDS. These were involved in various processes such as transcription, amino acid transport, metabolism, and gene repair, which may have conferred advantages in growth, survival and/or host-pathogen interaction.