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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Ruminant Diseases and Immunology Research » Research » Publications at this Location » Publication #110907
Title: A FACTOR DERIVED FROM ADULT RAT AND COW SMALL INTESTINE REDUCES CRYPTOSPORIDIUM PARVUM INFECTION IN INFANT RATS

Author
item AKILI, DHUHA - IOWA STATE UNIV., AMES
item Harp, James

Submitted to: Journal of Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/4/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary: Cryptosporidium parvum is an intestinal parasite that causes diarrhea in both people and young livestock, especially calves. There are no drugs available to treat this disease, and no vaccines to prevent it. Since adult animals are usually resistant in Cryptosporidium infection, we took mucous from the intestines of adult rats or cows, and fed it to infant rats. These rats were protected against infection with Cryptosporidium. These results show that there are differences in the intestines of adult animals that make them resistant to Cryptosporidium, and this resistance can be transferred to young animals. Identifying these differences will lead to ways of protecting young calves against Cryptosporidium infection. This will result in an economic benefit to cattle producers and consumers, and will also help to protect the environment from contamination with this parasite.

Technical Abstract: Cryptosporidium parvum is an intracellular protozoan parasite of the mammalian intestine. In rats, C. parvum infection is age related; infants are susceptible, while adults are resistant. The transition from susceptibility to resistance usually takes place around the age of weaning. In the present study, infant rats were orally inoculated with a preparation of intestinal scrapings taken from adult rats or cows. Infant rats received the scrapings daily from 3 to 14 days of age, were inoculated with C. parvum oocysts at 9 days of age, and killed at 15 days of age. Fecal samples and intestinal tissues were examined for the presence of C. parvum. Significantly fewer rats were infected in the groups that received intestinal scrapings compared with controls. In addition, infected rats in the treatment groups shed significantly fewer oocysts than did infected rats in the control group. Scrapings from the intestinal mucosa of adult cows were also able to protect infant rats from infection, while scrapings from intestines of calves were not protective. In sum, these data indicate the presence of a factor in the intestines of adult rats and cows that can transfer protection against C. parvum infection to susceptible infant rats.