The Western Fence Lizard (Sceloporus occidentalis) is a major host of juvenile stages of the Western Black-legged Tick (Ixodes pacificus), which is the vector for the Lyme disease causative spirochete bacterium Borrelia burgdorferi in the western United States. Because S. occidentalis is reservoir incompetent and capable of eliminating spirochetes from infected ticks, it has been implicated as a major factor in the ecology of Lyme disease in the West. Although complement proteins in lizard blood have been established as the borreliacidal factor, no studies have examined intraspecific variability in host lizard borreliacidal capacity. In Chapter 1 of this thesis, we introduce the complexity of the Borrelia burgdorferi transmission cycle and it’s implications for transmission risk. In Chapter 2 we tested the hypothesis that host lizard physiological condition impacts their borreliacidal capacity. Blood plasma of lizards in varying physiological conditions was challenged against cultured B. burgdorferi, and the complement-mediated inactivation of spirochetes was quantified. Adult lizards had higher bactericidal activity than first-year juveniles, suggesting that complement-mediated inactivation develops with maturity and/or exposure to spirochete antigens. Also, bactericidal activity was positively associated with lizard tick load and body condition. Adult lizard sex did not significantly affect spirochete mortality. Lizards from an inland site with little exposure to ticks had higher bactericidal activity than lizards from a coastal population that is heavily parasitized by ticks.
","abstract_html":"<p>The Western Fence Lizard (<em>Sceloporus occidentalis</em>)<em> </em>is a major host of juvenile stages of the Western Black-legged Tick (<em>Ixodes pacificus</em>), which is the vector for the Lyme disease causative spirochete bacterium <em>Borrelia burgdorferi</em> in the western United States.<em> </em>Because <em>S. occidentalis</em> is reservoir incompetent and capable of eliminating spirochetes from infected ticks, it has been implicated as a major factor in the ecology of Lyme disease in the West. Although complement proteins in lizard blood have been established as the borreliacidal factor, no studies have examined intraspecific variability in host lizard borreliacidal capacity. In Chapter 1 of this thesis, we introduce the complexity of the <em>Borrelia burgdorferi</em> transmission cycle and it’s implications for transmission risk. In Chapter 2 we tested the hypothesis that host lizard physiological condition impacts their borreliacidal capacity. Blood plasma of lizards in varying physiological conditions was challenged against cultured <em>B. burgdorferi</em>, and the complement-mediated inactivation of spirochetes was quantified. Adult lizards had higher bactericidal activity than first-year juveniles, suggesting that complement-mediated inactivation develops with maturity and/or exposure to spirochete antigens. Also, bactericidal activity was positively associated with lizard tick load and body condition. Adult lizard sex did not significantly affect spirochete mortality. Lizards from an inland site with little exposure to ticks had higher bactericidal activity than lizards from a coastal population that is heavily parasitized by ticks.</p>","abstract_has_math":false,"creators":["Weichert, Kyle Russell"],"institution":null,"degree_name":"MS in Biological Sciences","degree_level":null,"degree_discipline":"Biological Sciences","degree_department":null,"school":null,"contributors":["Emily Taylor"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-06-01T07:00:00Z","date_published":"2015-06-01T07:00:00Z","updated_at":"2026-07-24T01:32:42Z","subjects":["Borrelia burgdorferi","Lyme Disease","Sceloporus occidentalis","Ixodes pacificus"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["10.15368/theses.2015.73"],"render_values":[{"text":"10.15368/theses.2015.73","href":"https://doi.org/10.15368/theses.2015.73","code":true}]}]},"links":{"outbound_url":"https://digitalcommons.calpoly.edu/theses/1416","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Emily Taylor"]},{"key":"dc:creator","label":"Author","values":["Weichert, Kyle Russell"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2016-06-09T07:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biological Sciences"]},{"key":"thesis:degree_name","label":"Degree Name","values":["MS in Biological Sciences"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Borrelia burgdorferi","Lyme Disease","Sceloporus occidentalis","Ixodes pacificus"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://digitalcommons.calpoly.edu/theses/1416","10.15368/theses.2015.73"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The Western Fence Lizard (Sceloporus occidentalis) is a major host of juvenile stages of the Western Black-legged Tick (Ixodes pacificus), which is the vector for the Lyme disease causative spirochete bacterium Borrelia burgdorferi in the western United States. Because S. occidentalis is reservoir incompetent and capable of eliminating spirochetes from infected ticks, it has been implicated as a major factor in the ecology of Lyme disease in the West. Although complement proteins in lizard blood have been established as the borreliacidal factor, no studies have examined intraspecific variability in host lizard borreliacidal capacity. In Chapter 1 of this thesis, we introduce the complexity of the Borrelia burgdorferi transmission cycle and it’s implications for transmission risk. In Chapter 2 we tested the hypothesis that host lizard physiological condition impacts their borreliacidal capacity. Blood plasma of lizards in varying physiological conditions was challenged against cultured B. burgdorferi, and the complement-mediated inactivation of spirochetes was quantified. Adult lizards had higher bactericidal activity than first-year juveniles, suggesting that complement-mediated inactivation develops with maturity and/or exposure to spirochete antigens. Also, bactericidal activity was positively associated with lizard tick load and body condition. Adult lizard sex did not significantly affect spirochete mortality. Lizards from an inland site with little exposure to ticks had higher bactericidal activity than lizards from a coastal population that is heavily parasitized by ticks.
"]},{"key":"dc:title","label":"Title","values":["Physiological Factors Affecting the Bactericidal Activity of the Western Fence Lizard (Sceloporus occidentalis) for the Lyme Disease Spirochete, Borrelia burgdorferi"]}]}],"canonical_facts":{"dc:contributor":["Emily Taylor"],"dc:creator":["Weichert, Kyle Russell"],"dc:date.available":["2016-06-09T07:00:00Z"],"dc:description.abstract":["The Western Fence Lizard (Sceloporus occidentalis) is a major host of juvenile stages of the Western Black-legged Tick (Ixodes pacificus), which is the vector for the Lyme disease causative spirochete bacterium Borrelia burgdorferi in the western United States. Because S. occidentalis is reservoir incompetent and capable of eliminating spirochetes from infected ticks, it has been implicated as a major factor in the ecology of Lyme disease in the West. Although complement proteins in lizard blood have been established as the borreliacidal factor, no studies have examined intraspecific variability in host lizard borreliacidal capacity. In Chapter 1 of this thesis, we introduce the complexity of the Borrelia burgdorferi transmission cycle and it’s implications for transmission risk. In Chapter 2 we tested the hypothesis that host lizard physiological condition impacts their borreliacidal capacity. Blood plasma of lizards in varying physiological conditions was challenged against cultured B. burgdorferi, and the complement-mediated inactivation of spirochetes was quantified. Adult lizards had higher bactericidal activity than first-year juveniles, suggesting that complement-mediated inactivation develops with maturity and/or exposure to spirochete antigens. Also, bactericidal activity was positively associated with lizard tick load and body condition. Adult lizard sex did not significantly affect spirochete mortality. Lizards from an inland site with little exposure to ticks had higher bactericidal activity than lizards from a coastal population that is heavily parasitized by ticks.
"],"dc:identifier":["https://digitalcommons.calpoly.edu/theses/1416","10.15368/theses.2015.73"],"dc:subject":["Borrelia burgdorferi","Lyme Disease","Sceloporus occidentalis","Ixodes pacificus"],"dc:title":["Physiological Factors Affecting the Bactericidal Activity of the Western Fence Lizard (Sceloporus occidentalis) for the Lyme Disease Spirochete, Borrelia burgdorferi"],"thesis:degree_discipline":["Biological Sciences"],"thesis:degree_name":["MS in Biological Sciences"]},"updated_at":"2026-07-24T01:32:42Z"}