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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Environmental Microbial & Food Safety Laboratory » Research » Research Project #430168

Research Project: Zoonotic Parasites Affecting Food Animals, Food Safety, and Public Health

Location: Environmental Microbial & Food Safety Laboratory

Project Number: 8042-32000-100-000-D
Project Type: In-House Appropriated

Start Date: Dec 20, 2015
End Date: Dec 19, 2020

Objective 1: Conduct whole-genome sequencing to characterize the differences between zoonotic/non-zoonotic and pathogenic/non-pathogenic Cryptosporidium, Giardia, Blastocystis, and Enterocytozoon bieneusi. Objective 2: Develop intervention and treatment strategies against zoonotic parasites Cryptosporidium and Giardia. Subobjective 2.A. Evaluate the ability of probiotics to prevent/ameliorate the negative effects of cryptosporidiosis and giardiasis in rodent models of infections. Subobjective 2.B. Evaluate glucagon-like peptide 2 (GLP-2) and feed additives that enhance basal GLP-2 secretion on pre-weaned calves as an intervention and treatment for cryptosporidiosis and giardiasis. Objective 3: Develop a unique and highly sensitive assay to detect the zoonotic protists Cryptosporidium, Giardia, Blastocystis, Encephalitozoon and Enterocytozoon in food and environmental samples by targeting intracellular viral symbionts of these parasites and water-borne pathogens. Subobjective 3.A. Detecting Cryptosporidium parvum and Giardia duodenalis by targeting intracellular viral symbionts of these parasites. Subobjective 3.B. Identifying viruses and recovering viral RNA from Blastocystis, Encephalitozoon and Enterocytozoon, and develop detection assays based on the viral symbionts.

Cryptosporidium, Giardia, Blastocystis, and Microsporidia are cosmopolitan microscopic parasites that cause severe diarrheal disease in humans and animals, and can be lethal in immunecompromised individuals. These parasites are spread by fecal contamination, are waterborne, and have been identified as contaminants of fresh fruit and vegetables. To identify the genomic basis of host specificity and virulence for Cryptosporidium, Giardia, Blastocystis, and Enterocytozoon bieneusi, we will conduct whole genome sequencing and use comparative genomic analysis between zoonotic/non-zoonotic and pathogenic/non-pathogenic organisms. Furthermore, because current detection methods lack sensitivity that results in potential underreporting of produce contamination, we will develop new highly sensitive assays based on molecular detection targeting intracellular viral symbionts of these parasites. These assays will enable better detection of zoonotic protist parasites in food, and provide for a better understanding of the role of food animals in the epidemiology of these organisms. Because there are no vaccines or preventable medicines for Cryptosporidium and Giardia, we plan to evaluate different products to prevent disease spread and/or symptoms for Cryptosporidium and Giardia. We will assess products with the potential to be incorporated as feed additives for animals and humans using randomized clinical trials to evaluate their efficacy. To evaluate effectiveness for probiotics we will use rodent challenge models (mice and gerbil), and for GLP-2 and/or Sucram a calf challenge model.