Analysis of Wild Rodent Gut Microbiota as a Function of Exposure to Ticks and Tick-borne Pathogens

Author

Joshua Pandian, University of RichmondFollow

Date of Award

4-27-2023

Document Type

Thesis

Degree Name

Bachelor of Science

Department

Biology

First Advisor

Jory Brinkerhoff

Abstract

Due to advances in high-throughput parallel sequencing, researchers have conducted novel studies exploring relationships between microbiome compositions and different aspects of organism health. Some of these studies have shown that the gut microbiome of rodent models has effects on organism health and behavior and that infection with pathogens and the composition of the skin microbiome are linked to changes in gut microbiome composition. While previous studies have shown how vector microbiota impact vector behavior and pathogen transmission, the effect vectors have on reservoir species microbiomes has been a less prominent focus. We were interested in the relationships between tick parasitism, tick-borne pathogens, and host rodent microbiomes. As ticks interact with the skin, it is reasonable to believe tick parasitism can affect the host skin microbiome, which can affect the gut microbiome and overall rodent health. Additionally, tick-borne pathogens could possibly affect the skin and gut microbiome, resulting in health or behavioral changes. However, it is difficult to determine if tick parasitism and pathogens are affecting the host microbiome, or if certain genetic, behavioral, and microbiome factors in the host promote tick parasitism and pathogen susceptibility. To determine what relationships were present in this system, we first sampled two species of rodents (Peromyscus leucopus and Sigmodon hispidus). We detected significant variation in gut microbiota among species, but not between sampling sites. Moreover, we found gut microbiome composition, as well as microbial richness, to vary as a function of tick parasitism and infection with the Lyme disease agent, Borrelia burgdorferi, although we note that some of these differences were species-specific. Based on the results of this study, we performed a follow up experimental study on lab mice in which we collected gut microbiome data before and after Ixodes scapularis tick parasitism. Our preliminary analysis detects that both tick parasitism and the origin of the ticks used (coastal or mountain) could influence rodent microbiome composition.

Recommended Citation

Pandian, Joshua, "Analysis of Wild Rodent Gut Microbiota as a Function of Exposure to Ticks and Tick-borne Pathogens" (2023). Honors Theses. 1683.
https://scholarship.richmond.edu/honors-theses/1683