LE3 .A278 2016

2016

Smith, Todd

Acadia University

Bachelor of Science

Honours

Biology

Biology

Hepatozoon clamatae and Hepatozoon catesbianae are malaria-like erythocytic parasites that preferentially infect the erythrocytes of green frogs and bullfrogs, respectively, and often occur simultaneously in both species. The purpose of this research was to monitor parasitaemia (i.e., infection levels) in laboratory-raised green frogs, infected with various combinations of Hepatozoon clamatae and Hepatozoon catesbianae, to investigate competition that may occur between the two parasite species within experimentally infected green frogs. PCR technology was used to develop a method of differentiating between the two Hepatozoon species at the molecular level to allow more accurate evaluation of infection levels. Source frogs naturally infected with one or both Hepatozoon species, and larvae and pupae of the mosquito vector, Culex territans, were caught from ponds in Kings County, Nova Scotia. Mosquitoes were fed on source frogs to acquire infection, and were later fed to laboratory-raised frogs. Parasitaemia was monitored every 10 days for 120 days. Due to the occurrence of asexual division, or erythrocytic merogony, in cohorts 3, 4, and 5, differentiation between species was not made until 80 days post-inoculation. Based on the linear mixed-effects model, it was determined that in the instance of a pure H. clamatae infection, there is a significant decrease in parasitaemia between 80 and 100 days, while in contrast,the same decrease is not found in the case of mixed infections. This suggests that there is a phenomenon occurring in mixed infections that causes parasitaemia to remain constant. Additionally, with a 3:1 mixed infection of H. clamatae to H. catesbianae, the proportion of H. clamatae remained significantly higher than H. catesbianae; however the details regarding the specific interaction between the two parasites could not be fully resolved

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https://scholar.acadiau.ca/islandora/object/theses:1471