First report of pathogenic Leptospira in Sri Lankan bats: A potential reservoir risk?

backgroundThe genus Leptospira, classified under the phylum Spirochaetes, includes saprophytic, intermediate, and pathogenic species. Pathogenic Leptospira spp. are the causative agents of leptospirosis, a widespread and often neglected zoonotic disease that causes severe illness in humans, particularly in tropical and subtropical regions. In Sri Lanka, leptospirosis causes annual outbreaks, especially during the monsoon seasons. While rodents are recognized as primary reservoirs, bats have also been identified as potential reservoir hosts. This study aimed to detect and characterize Leptospira species in bats roosting in Wavulgalge cave, Sri Lanka. METHODOLOGY/PRINCIPAL

findingsUrine samples (n = 148) were collected during natural urination from four bat species: Miniopterus fuliginosus (n = 117), Hipposideros speoris (n = 8), Rousettus leschenaultii (n = 10), and Rhinolophus rouxii (n = 13). DNA was extracted and screened for Leptospira using real-time PCR targeting the lipL32 gene. Sixteen samples tested positive, including 14 from M. fuliginosus, one from H. speoris, and one from R. leschenaultii. Positive samples were further analyzed by amplifying additional loci (flaB, secY, and rrs2) for Sanger sequencing and phylogenetic analysis. Sequences were obtained from 12 samples. Leptospira borgpetersenii was identified in M. fuliginosus, while the sequence from R. leschenaultii represented a genetically distinct Leptospira species. Phylogenetic analysis showed clustering with sequences from the same bat host genera reported in other countries, and one L. borgpetersenii sequence clustered with strains previously detected in Sri Lankan hosts, including humans. CONCLUSIONS/SIGNIFICANCE: This study provides the first molecular evidence of Leptospira in Sri Lankan bats and highlights their potential role as reservoirs contributing to the environmental circulation of pathogenic Leptospira.