Biology ETDs

Publication Date



Sporulated oocysts of Eimeria nieschulzi Dieben, 1924, a rat coccidium, were exposed to radiation, to heat, or to both in an effort to attenuate the parasite. In addition, studies were conducted on the excystation capabilities and infectivity of treated sporozoites and on their immunogenic potential. These observations were correlated with the immune response of the host. Treatments had no effect on oocyst structure but altered the excystation process and decreased the percentage of sporozoites capable of excysting. Moderate levels of radiation, of heat, or of both radiation and heat attenuated the parasite, reduced pathological effect (as judged by oocyst discharge during primary infection), and produced immunity to challenge. The immune response of the host affected the parasite's development prior to the second generation schizont. This information suggests that oocysts treated by radiation, by heat, or by a combination of radiation and heat might be used as a "vaccine." Treated oocysts fed to animals may reduce pathological effects during a primary infection and yet give good protection against further coccidial infection.



Document Type


Degree Name


Level of Degree


Department Name

UNM Biology Department

First Committee Member (Chair)

Donald Walter Duszynski

Second Committee Member

Clarence Clayton Hoff

Third Committee Member

Clifford Smeed Crawford

Fourth Committee Member

James Roman Gosz

Fifth Committee Member

J. Pat Brannon

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Biology Commons