Genetic diversity of pathogenic Leptospira spp. harbored by bats in Japan

Leptospirosis is a zoonotic infectious disease caused by pathogenic Leptospira species. In Japan, human and canine leptospirosis cases are reported annually. Although wild animals, including bats, are known to harbor pathogenic Leptospira spp., infection of bats in this region has never been explored. This study aimed to determine the presence of leptospires and their genetic diversity in five Japanese bat species. Kidney tissue and blood samples were collected from 115 bats captured in the Yamaguchi Prefecture and Hokkaido, Japan. Pathogenic Leptospira spp. were detected in the kidneys by real-time PCR and conventional PCR using primers targeting lipL32 and rrs2. Multilocus sequence typing (MLST) and sequencing of secY gene were performed on PCR-positive DNA samples. Leptospira spp. were detected in 26 of the 115 bats (22.6 %), including Rhinolophus ferrumequinum (5/37, 14 %), Rhinolophus cornutus (2/6, 33 %), Miniopterus schreibersii (6/37, 16 %), Myotis macrodactylus (11/15, 73 %), and Vespertilio sinensis (2/20, 10 %). Phylogenetic analysis based on MLST genes and secY gene revealed detected genes clustered with either L. interrogans, L. borgpetersenii, or L. kirschneri and a relationship between the leptospires identified in the bats in this study and bats in other countries or other host, and PCR with L. borgpetersenii-specific primers revealed co-infection with multiple Leptospira species in individual bats. Our study demonstrated a high carriage rate, genetic diversity of Leptospira spp., and co-infection with multiple Leptospira spp. in Japanese bats.