Experimental Hamster Infection with a Strain of Leptospira borgpetersenii Ballum Isolated from a Reservoir Mouse in New Caledonia.

Leptospirosis is a neglected zoonosis caused by pathogenic Leptospira. In this study, we characterized the virulence of isolate B3-13S obtained from a wild mouse (Mus musculus) captured in New Caledonia, subsequently identified as a bacterium belonging to the L. borgpetersenii serogroup Ballum. Hamsters were infected with an intraperitoneal injection of 2 × 10(8) bacteria, resulting in severe histopathological organ damages consistent with tissue lesions previously observed with other strains. Hamsters were also injected with 1 × 10(8) or 5 × 10(7) bacteria and animals that recovered showed renal carriage of leptospires in concentrations similar to the bacterial load quantified in mouse kidneys, with urinary shedding of bacteria up to 4 weeks postinfection. The serogroup Ballum is increasingly reported in human leptospirosis, and these results highlight the use of the B3-13S isolate for the development of models resulting in either severe acute or chronic forms of the infection, allowing for better characterization of its pathogenesis.