LE3 .A278 2023

2023

Smith, Todd
Ferguson, Laura

Acadia University

Bachelor of Science

Honours

Biology

Biology

Little is known about immune responses elicited by mosquitoes that are infected with Hepatozoon species. Production of reactive oxygen species (ROS) is a typical immune response of mosquitoes against other apicomplexan parasites, including the causative agents of human malaria, and against Hepatozoon species acquired from the blood of frogs. Previous work in our laboratory revealed that oxidative activity increased in the haemocoel of Culex territans mosquitoes that had taken blood meals from snakes with high infections of Hepatozoon sipedon (i.e., parasitaemia of 5%) when compared to uninfected individuals. The objectives of this study, therefore, were to analyze the ROS response elicited by C. territans when infected with light (~0.01% parasitaemia) or moderate (0.1% parasitaemia) infections of H. sipedon from the blood of Common Garter Snakes (Thamnophis sirtalis), and to identify if there is a generalized immune response generated by mosquito vectors against infections with Hepatozoon species from different vertebrates. The concentration of peroxide from the dissected midgut and haemocoel of mosquitoes fed on infected snakes was determined using a peroxide assay as a surrogate for oxidative activity. A high concentration of peroxide was observed both in the haemocoel and in the midgut of infected mosquitoes. Oxidative activity was similar in the midgut of mosquitoes at both infection levels. Combining data from this study with those from previous research in our laboratory revealed a strong if not significant trend for a higher concentration of peroxide as infection level increased. These findings from the haemocoel of C. territans are similar to previous work on Hepatozoon species of frogs, indicating the importance of this type of immune esponse against parasites moving through the haemocoel en route to their location of further development.

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https://scholar.acadiau.ca/islandora/object/theses:4036