Identification of Pathogenic Serogroup Grippotyphosa in Water Voles () from Ruminant Pastures in Puy-de-Dôme, Central France.

Rodents are the primary reservoirs for pathogenic species, which cause leptospirosis. Among the key potential carriers are water voles, whose population outbreaks can consequently pose a major threat to human and animal health. We studied the prevalence, prominence, and epidemiology of pathogenic species in water voles in central France. First, 46 voles were captured, and DNA was extracted from kidney, lung, liver, blood, and urine and tested for the presence of using three molecular methods: PCR, O-antigen typing, and variable number tandem repeat (VNTR) typing. We also attempted to culture leptospires from kidney and urine samples. In addition, we investigated leptospiral antibodies in serum samples from 60 sheep using microscopic agglutination testing. These animals co-occurred with the voles, so we sought to assess their degree of exposure and involvement in pathogen dynamics. The overall prevalence of infection was 76.1% (CI [61.2%, 87.4%]). The only strain found was serogroup Grippotyphosa and a similar VNTR profile was acquired. Leptospires were successfully cultured from kidney and urine samples for four voles. Three sheep had low antibody titers against the serogroup Grippotyphosa. Taken together, our results suggest the exclusive carriage of serogroup Grippotyphosa among water voles in central France. Nevertheless, their ability to act as reservoir hosts that transmit the pathogen to co-occurring livestock remains unclear and merits further research.