Investigating the Impact of Host Blood Meal Identity on Ixodes pacificus Microbiome Composition Using a Multi-Species Analysis of Small Mammals and Reptiles

Author: Mariah Angel Cuyson

Faculty Supervisor: Andrea Swei

Department: Biology

Lyme disease, caused by the pathogenic spirochete Borrelia burgdorferi and vectored by the tick species Ixodes pacificus on the West Coast, is one of the most commonly reported tick-borne diseases in the United States, posing a major public health risk to humans and wildlife. Previous research has investigated the key natural drivers in tick microbiome variation and its role within pathogen transmission dynamics of Lyme disease. A fundamental finding from this research suggests the significant role of host blood meal identity in modulating the I. pacificus microbiota and its influence on pathogen acquisition. The objective of this study is to further investigate the impact of host blood meal identity on I. pacificus microbiome composition and richness by developing a multi-species analysis on a variety of small mammal and reptile species varying in reservoir host competency of B. burgdorferi. Engorged I. pacificus larvae burdens collected from important I. pacificus host blood meal sources, such as small mammals and reptiles along seven oak woodland habitats in northern California, were preserved and analyzed using Next-Generation Sequencing of the hypervariable V3 - V4 regions of the 16S ribosomal RNA gene for microbial community identification and characterization.