Biogeography of Leptospira in wild animal communities inhabiting the insular ecosystem of the western Indian Ocean islands and neighboring Africa

Muriel Dietrich (1) , Yann Gomard (1) , Erwan Lagadec (1) , Beza Ramasindrazana (1) , Gildas Le Minter (1) , Vanina Guernier (1) , Aude Benlali (1) , Gérard Rocamora (2) , Wanda Markotter (3) , Steven Goodman (4) , Koussay Dellagi (1) , Pablo Tortosa (1)

1 PIMIT - Processus Infectieux en Milieu Insulaire Tropical
2 University of Seychelles
3 University of Pretoria [South Africa]
4 Field Museum of Natural History [Chicago, USA]

Understanding the processes driving parasite assemblages is particularly important in the context of zoonotic infectious diseases. Leptospirosis is a widespread zoonotic bacterial infection caused by pathogenic species of the genus Leptospira. Despite a wide range of animal hosts, information is still lacking on the factors shaping Leptospira diversity in wild animal communities, especially in regions, such as tropical insular ecosystems, with high host species richness and complex biogeographical patterns. Using a large dataset (34 mammal species) and a multilocus approach at a regional scale, we analyzed the role of both host species diversity and geography in Leptospira genetic diversity in terrestrial small mammals (rodents, tenrecs, and shrews) and bats from 10 different islands/countries in the western Indian Ocean (WIO) and neighboring Africa. At least four Leptospira spp. (L. interrogans, L. borgpetersenii, L. kirschneri, and L. mayottensis) and several yet-unidentified genetic clades contributed to a remarkable regional Leptospira diversity, which was generally related to the local occurrence of the host species rather than the geography. In addition, the genetic structure patterns varied between Leptospira spp., suggesting different evolutionary histories in the region, which might reflect both in situ diversification of native mammals (for L. borgpetersenii) and the more recent introduction of non-native host species (for L. interrogans). Our data also suggested that host shifts occurred between bats and rodents, but further investigations are needed to determine how host ecology may influence these events.

Domaines: Bactériologie; Biodiversité et Ecologie; Ecosystèmes; Médecine vétérinaire et santé animale; Santé

Muriel Dietrich, Yann Gomard, Erwan Lagadec, Beza Ramasindrazana, Gildas Le Minter, et al.. Biogeography of Leptospira in wild animal communities inhabiting the insular ecosystem of the western Indian Ocean islands and neighboring Africa. Emerging microbes & infections, 2018, 7, pp.57. ⟨10.1038/s41426-018-0059-4⟩. ⟨hal-01876559⟩