Peromyscus species as a rodent model of acute Leptospirosis

Authors: Putz, Ellie; ANDREASEN, CLAIRE - Iowa State University; Boggiatto, Paola; Palmer, Mitchell; FERNANDES, LUIS - Oak Ridge Institute For Science And Education (ORISE); Tibbs-Cortes, Bienvenido; Stasko, Judith; HAMOND, CAMILA - Oak Ridge Institute For Science And Education (ORISE); Olsen, Steven; Nally, Jarlath

Submitted to: Emerging Infectious Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/2/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: While most rodents such as mice and rats present with asymptomatic clinical signs of leptospirosis infection, the hamster animal model presents with severe acute and often fatal disease. Because of this, hamsters are often relied upon for all virulence testing as well as vaccine efficiency testing for Leptospira research. Interestingly the Peromyscus deer mice are more closely related to hamsters than traditional mice. Deer mice are found in the wild and are reservoir hosts for other spirochete diseases such as Lyme disease. In this work we challenged male and female deer mice with two different species of virulent Leptospira. The Peromyscus deer mice presented with acute disease, more similar to the hamster, as well as modeled a sex effect where males were more susceptible to severe disease than females. This work identifies a novel acute rodent model of leptospirosis.

Technical Abstract: Leptospirosis is a devastating zoonotic disease affecting humans, companion, and domestic animals around the world. Incidental hosts primarily contract the disease from asymptomatic reservoir hosts; the most common being small rodents. In leptospirosis research, the Golden Syrian Hamster is widely recognized as the dominant rodent model for acute disease as they are susceptible to many serovars and can be used to maintain laboratory strains and test bacterin vaccine efficacy. However, while hamsters are primarily utilized in survival-based studies, they are limited by a lack of reagents that would enable deeper immunological analysis. This work describes an alternative rodent model, Peromyscus leucopus, commonly known as deer mice, that are susceptible to acute disease and may serve as an alternative rodent model for acute leptospirosis. Similar to the hamster, deer mice also produce circulating foamy macrophages in response to leptospiral disease challenge. As reported in other host species, deer mice exhibit a difference in response to different serovars, clinical disease severity, kidney and liver lesions, and an overall sex effect, where males present with more severe clinical signs and a higher bacterial burden.