Ecological range and host-biome associations of pathogenic Leptospira in Brazil: A One Health perspective from a tropical area.

Pathogenic Leptospira spp. cause a globally distributed zoonosis with complex transmission cycles involving multiple hosts and environments. Brazil's vast ecological diversity and high Leptospira spp. circulation demand integrative approaches to understand the pathogen's genetic diversity and distribution. We compiled an extensive molecular dataset of pathogenic Leptospira spp. in Brazil, encompassing sequences (n = 825) from several genetic markers and WGS data. A molecular landscape was provided based on associated metadata, including host species, geographic origin, and source type (clinical, animal, environmental). Records spanned four Brazilian biomes, with the highest diversity and number of sequences from the Atlantic Forest (69.7 %) and Amazon (22.2 %), with emphasis on large urban centers. Leptospira interrogans predominated (74.9 %), followed by L. santarosai (9.8 %), L. borgpetersenii (7.2 %), L. kirschneri (3.9 %), and L. noguchii (3.9 %). Regarding serogroups, Icterohaemorrhagiae was the most frequent (44.9 %). Hosts encompassed 78 species from 12 orders, including domestic large land animals (36 %), wild land animals (21 %), humans (15 %), pets (13.8 %), urban rodents (7.6 %), and marine mammals (1.3 %). Importantly, sequences from environmental pathogenic leptospires were also identified (5.3 %). This integrative molecular analysis reveals the extensive diversity, ecological breadth, and complex transmission dynamics of pathogenic Leptospira in those biomes. The findings underscore the importance of a One Health perspective and provide a robust foundation for standardized molecular surveillance and targeted interventions to mitigate leptospirosis burden in tropical regions.