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Co-Feeding Transmission of the Ehrlichia muris-Like Agent to Mice (Mus musculus)
Sandor E Karpathy1, Michelle E J Allerdice1, Mili Sheth1
11 Rickettsial Zoonoses Branch, Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services , Atlanta, Georgia .
Abstract:
The Ehrlichia muris-like agent (EMLA) is a newly recognized human pathogen found in Wisconsin and Minnesota. Ecological investigations have implicated both the blacklegged tick, Ixodes scapularis, and the white-footed mouse, Peromyscus leucopus, as playing roles in the maintenance of EMLA in nature. The work presented here shows that I. scapularis is an efficient vector of EMLA in a laboratory mouse model, but that Dermacentor variabilis, another frequent human biting tick found in EMLA endemic areas, is not. Additionally, I. scapularis larvae are able to acquire EMLA through co-feeding with infected nymphs. As EMLA only persists in mouse blood for a relatively short period of time, co-feeding transmission may play an important role in the maintenance of EMLA in ticks, and subsequently may play a role in limiting the geographic distribution of this pathogen in areas where co-feeding of larvae and nymphs is less common.
Insights
The blacklegged tick (Ixodes scapularis) efficiently transmits the Ehrlichia muris-like agent (EMLA), a new pathogen. Co-feeding transmission among ticks may influence EMLA
Area of Science:
- Veterinary Entomology
- Infectious Diseases
- Zoonotic Pathogens
Background:
- The Ehrlichia muris-like agent (EMLA) is an emerging human pathogen identified in Wisconsin and Minnesota.
- Ecological studies suggest Ixodes scapularis ticks and Peromyscus leucopus mice are key reservoirs for EMLA.
- Understanding EMLA transmission dynamics is crucial for public health in endemic regions.
Purpose of the Study:
- To evaluate the vector competence of Ixodes scapularis and Dermacentor variabilis for EMLA.
- To investigate potential transmission mechanisms of EMLA within tick populations.
- To assess the role of co-feeding in EMLA maintenance and geographic distribution.
Main Methods:
- Laboratory experiments using a mouse model to assess EMLA transmission by Ixodes scapularis and Dermacentor variabilis.
- Infection prevalence assays in ticks exposed to infected mice.
- Investigation of larval EMLA acquisition through co-feeding with infected nymphs.
Main Results:
- Ixodes scapularis was confirmed as an efficient laboratory vector of EMLA.
- Dermacentor variabilis did not prove to be an effective vector for EMLA.
- Ixodes scapularis larvae successfully acquired EMLA via co-feeding with infected nymphs.
Conclusions:
- Ixodes scapularis plays a significant role in EMLA transmission.
- Co-feeding transmission is a potentially important mechanism for EMLA maintenance in tick populations.
- Limited co-feeding may restrict the geographic spread of EMLA.
