# Retrotransposon assay for tick host bloodmeal identification

> **NIH NIH R01** · TUFTS UNIVERSITY BOSTON · 2020 · $407,800

## Abstract

Project Summary/Abstract.
The public health burden due to Lyme disease continues to expand in the eastern United States.
New interventions to reduce risk are needed to complement well-known methods such as
acaricidal applications or personal protection. Reservoir targeted approaches such as oral
vaccination, feed through acaricides or genetic modifications are currently under development
or are being field tested. These newer strategies focus on the white footed mouse, Peromyscus
leucopus, which is widely regarded as the main host for subadult deer ticks (Ixodes dammini or
I. scapularis), the vector for Lyme disease and diverse other zoonotic infections in the
northeastern U.S. Indeed, this mouse has been incriminated as the main northeastern U.S.
reservoir host for the agent of Lyme disease (Borrelia burgdorferi) as well as for that of human
babesiosis (Babesia microti) and deer tick virus encephalitis. However, the evidence that P.
leucopus is the main host for subadult deer ticks is largely descriptive using indirect
extrapolations and comprise limited observations from a small number of sites. The ideal
means of incriminating a reservoir host is to determine the source of the bloodmeal that served
to infect the vector but assays that have been described to date for ticks have been poorly
reproducible or insensitive. Our overarching goal for this proposed project is to provide a
means to better understand natural variability of the relative contribution of other host species
on the transmission of the agent of Lyme disease. This is required to evaluate the costs and
benefits of mouse targeted interventions. We have determined that host retrotransposons may
be targeted by PCR assays and provide specific signatures of the bloodmeal taken by a tick in its
previous stage, and now seek to refine and validate this mode of analysis. Accordingly, we seek
to (1) develop and validate a sensitive, specific, simple and reproducible retrotransposon assay
for identifying the remnants of host bloodmeals in host-seeking nymphal deer ticks; (2) use this
assay to determine whether the Peromyscus blood index (PBI) may vary across sites and within
sites over time; and (3) experimentally confirm the PBI by undertaking interventions targeted
to mice and assaying host seeking nymphal deer ticks thereafter to determine whether there has
been a shift in hosts. Although our immediate goal is to provide a solid rationale for mouse
targeted interventions against Lyme disease, the assay itself could be adapted to better
understand the mode of perpetuation of diverse other tick-borne zoonoses.

## Key facts

- **NIH application ID:** 9976450
- **Project number:** 5R01AI130105-03
- **Recipient organization:** TUFTS UNIVERSITY BOSTON
- **Principal Investigator:** Sam R Telford
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $407,800
- **Award type:** 5
- **Project period:** 2018-08-06 → 2022-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9976450

## Citation

> US National Institutes of Health, RePORTER application 9976450, Retrotransposon assay for tick host bloodmeal identification (5R01AI130105-03). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9976450. Licensed CC0.

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