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Grantee Research Project Results

NCER Grantee Research Project Results

Diversity and Host Distribution of Avian Malaria Parasites

EPA Grant Number: F6F20571
Title: Diversity and Host Distribution of Avian Malaria Parasites
Investigators: Martinsen, Ellen S.
Institution: University of Vermont
EPA Project Officer: Zambrana, Jose
Project Period: September 1, 2006 through August 31, 2008
Project Amount: $109,982
RFA: STAR Graduate Fellowships (2006)
Research Category: Academic Fellowships , Biology/Life Sciences , Fellowship - Ecology , Fellowship - Evolutionary Biology

Description:

Objective:

The spectre of emerging infectious diseases is now a central concern for those involved in public health, veterinary medicine, and wildlife conservation. Host shifts by pathogens appear to be the primary genesis of emerging infectious diseases in humans and wildlife. Pathogens with wide geographic and host distributions are those that pose the most treat. Crucial to our understanding of emerging infectious diseases is knowledge regarding the diversity of pathogens cycling in wildlife populations and the host ranges for these pathogens. My research addresses the diversity and host distribution of a common group of pathogens of domestic and wild bird populations, the malaria parasites.

Approach:

Species identification is one of the major obstacles to studies of the diversity and distribution of the malaria parasites of birds (genera Plasmodium, Haemoproteus, and Leucocytozoon). Traditional morphological methods used to identify these parasites have not yet been compared with modern molecular methods of identification and thus the true diversity of these parasites is unknown. Additionally, although molecular studies of the avian malaria parasites have been undertaken, an applicable and appropriate species concept has not been identified. For these reasons, species identification has been questionable as well as our understanding of how these malaria parasites are distributed among avian hosts including their host range.

My research aims for the first time to couple morphological and molecular means of parasite identification to understand parasite diversity and distribution. Species identified using morphology as seen under the light microscope will be compared to species identified using gene sequence data. Such a comparison will shed light on the true diversity of the avian malaria parasites including the utility of morphological characters for defining species. Additionally, by sequencing genes from across the parasites’ three genomes, a thorough estimation of the evolutionary history of this group of pathogens will be possible including the identification of an appropriate species concept. Through sampling of the malaria parasites of a diversity of birds worldwide, I will be able to investigate how malaria parasite species are distributed among their avian hosts. This will allow identification of parasites with wide host ranges and thus the capability of switching hosts. These methods will allow an evaluation of the threat of malaria parasites as agents of emerging infectious disease in birds.

Expected Results:

Preliminary analyses indicate that although morphological characters used to identify species of avian malaria parasites may be useful in species identification, a diversity of parasites may be masked using morphology alone. Additionally, molecular analysis has revealed variability in the host range for the avian malaria parasites. Future results from this study including multi-gene analysis will shed light on the most appropriate method for species identification of the malaria parasites of birds. This will allow for a more thorough understanding of the diversity and distribution of the malaria parasites of birds, including the incidence of parasites with a wide host range that may pose threat to domestic and wild bird populations.

Supplemental Keywords:

Emerging Infectious Disease, Wildlife Pathogens, Avian Malaria, Bird Disease, Plasmodium, Haemoproteus, Leucocytozoon, Diversity, Distribution, Bird Parasites, Species Identification, Host Switching, Morphological Identification, Gene Sequencing, Phylogenetic Analysis, Pathogen Distribution, Pathogen Identification, Bird Populations, Bird Health,, RFA, Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, wildlife, Environmental Microbiology, Biology, Wildlife Risk Assessment, host distribution, pathogen, birds, parasites, conservation genetics, avian research, disease, genetic drift

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The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.

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