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Updated: Mar 8, 2026
Feeding of Ticks on Animals for Transmission and Xenodiagnosis in Lyme Disease Research
Published on: August 31, 2013
Experimental evaluation of Peromyscus leucopus as a reservoir host of the Ehrlichia muris-like agent
Geoffrey E Lynn1, Jonathan D Oliver2, Ingrid Cornax3
1Entomology Department, University of Minnesota - Twin Cities, 1980 Folwell Ave, St. Paul, MN, USA. lynnx044@umn.edu.
Background:
The Ehrlichia muris-like agent (EMLA) is a newly recognized human pathogen in the North Central United States. Although blacklegged ticks (Ixodes scapularis) have been identified as capable vectors, wild reservoirs have not yet been established for EMLA. As key hosts for I. scapularis, white-footed mice (Peromyscus leucopus) are important reservoirs for various tick-borne pathogens, and potentially, for EMLA. The objective of this study was to evaluate reservoir competence in P. leucopus using a natural vector.
Results:
Mice acquired EMLA infection from feeding ticks and were able to transmit infection to naïve ticks. Transmission between simultaneously feeding tick life stages was also demonstrated. Infections in mice were acute and severe, with systemic dissemination. Limited host survival and clearance of infection among survivors resulted in a narrow interval where EMLA could be acquired by feeding ticks.
Conclusions:
Peromyscus leucopus is a competent reservoir of EMLA and likely to play a role in its enzootic transmission cycle. The duration and severity of EMLA infection in these hosts suggests that tick phenology is a critical factor determining the geographic distribution of EMLA in North America.
Insights
White-footed mice (Peromyscus leucopus) are competent reservoirs for the Ehrlichia muris-like agent (EMLA), a new pathogen. These mice can transmit EMLA to ticks, impacting its spread in North America.
Area of Science:
- Veterinary Medicine
- Infectious Diseases
- Zoonotic Pathogens
Background:
- The Ehrlichia muris-like agent (EMLA) is an emerging pathogen in the North Central United States.
- Ixodes scapularis ticks are known vectors, but wild reservoirs remain unidentified.
- White-footed mice (Peromyscus leucopus) are primary hosts for I. scapularis and potential reservoirs for tick-borne diseases.
Purpose of the Study:
- To determine if Peromyscus leucopus can serve as a competent reservoir for EMLA.
- To assess the role of P. leucopus in the enzootic transmission cycle of EMLA.
Main Methods:
- Experimental infection of Peromyscus leucopus with EMLA via infected Ixodes scapularis.
- Monitoring of EMLA acquisition and transmission by mice to naïve ticks.
- Evaluation of infection severity, dissemination, and host survival.
Main Results:
- Mice became infected with EMLA after tick feeding and transmitted the pathogen to uninfected ticks.
- Simultaneous transmission between different tick life stages was observed.
- EMLA infections in mice were acute and severe, leading to systemic dissemination and limited host survival.
Conclusions:
- Peromyscus leucopus is confirmed as a competent reservoir for EMLA.
- The findings suggest P. leucopus plays a significant role in the enzootic transmission of EMLA.
- The severity and duration of EMLA infection in mice highlight the importance of tick phenology in EMLA's geographic distribution.
