Whole-genome sequencing to investigate Mycobacterium bovis strains circulating in the Dominican Republic

Abstract Background Bovine tuberculosis (bTB) by Mycobacterium bovis ( M. bovis ) is endemic in cattle in Latin America, and even though government programs exist for the control and eradication of the disease, efforts are hindered by the limited resources available for farmer compensation and program operation. Epidemiological surveillance and strain characterization are key for understanding disease dynamics, for which whole genome sequencing (WGS) is a powerful tool. Currently, there is limited information regarding bTB in the Caribbean, so the aim of this study was to use WGS to characterize M. bovis strains circulating in the Dominican Republic (DR). Results A total of 81 M. bovis isolates were obtained from cattle from different regions were sequenced and analyzed. Phylogenetic and ancestral reconstruction/temporal analyses were performed to investigate M. bovis genetic diversity, population structure, and potential dates of introduction into the Dominican Republic. Three main lineages were identified: DR1, DR2 (consisting of subgroups DR2a, DR2b, and DR2c), and DR3. Cluster analysis revealed at least four introductions of M. bovis during the 19th century and the first half of the 20th century. The most recent common ancestors to the DR lineages were linked to the United States, Mexico, Argentina, and Brazil, from where historical imports of cattle have occurred. Population structure analyses indicated that M. bovis is largely panmictic in the Dominican Republic, with no relationship between geographic location and genotype. Conclusion The current study provides important information regarding the origin of M. bovis strains circulating in the Dominican Republic, its genetic diversity and spread in the local cattle herds, providing a frame of reference for continuing M. bovis surveillance. Finally, this study significantly contributes to the worldwide M. bovis framework.