Molecular Phylogenetics, Diagnostics and Control of Apicomplexan Parasites

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Thelong term goal of my research program is to explore and understand the interactions betweenparasites of the phylum Apicomplexa and their hosts at the historical,organismal (host-parasite) and molecular levels. These parasites causeimportant animal and human diseases such as malaria, toxoplasmosis,cryptosporidiosis and coccidiosis. I propose to further our understanding ofthese relationships by pursuing three main areas of study:1) Investigate apicomplexan phylogeny and host-parasite coevolutionusing multi genome molecular markers with morphological and morphometriccharacters: We will determine the biodiversity of apicomplexan parasites inhumans, domesticated animals and wildlife (potential zoonotics) by generatingsequence data (nuclear 18S rDNA, plastid rDNA/polymerase B, and mt cytochrome c oxidase subunit I, COI) fromapicomplexan parasites that infect both domestic and, largely ignored, wildlifehosts. Our newly developed PCR primer pairs will generate species-specificCOI-based DNA barcodes that will be used to identify specifically coccidia(Eimeriorina) including enteric (e.g. Eimeria)and tissue (e.g. Toxoplasma)coccidia. We will modify our DNA barcode primers for use in a multiplexed NGSassay to both identify and enumerate mixed coccidia in biological samples suchas fecal or tissue samples; this method will permit rapid protistan parasitebiodiversity and species discovery;2)Generate complete mitochondrial (mt) genomes from biologically diverseapicomplexan parasites to explore the structural evolution of mt genomes andgenerate sequence data necessary for inferring the evolutionary history ofthese cosmopolitan parasites.3) Explore immunological control of coccidia of domestic poultry. Wewill determinethe natural prevalence of Eimeria that infect domestic turkeysnationally and internationally to determine the number of species required in amultivalent live coccidiosis vaccine against turkey coccidiosis. We will refine and further develop a recombinantmultivalent vaccine technology that combines two parasite antigenic epitopes with ahost-derived immune modulating epitope (HMGB1). The current Bacillus subtilis expression vector for this multivalentvaccine construct will be converted into a strictly peptide based (i.e.chemically synthesized) form and tested for biological activity in vivo whendelivered by various means.