| Abstract: | The purpose of this study was to determine possible antigenic differences in the causative organisms of the acute and chronic blood borne and tick borne Babesia bigemina infections of cattle. It was anticipated that the results of the research would further aid in the understanding of the mechanism of immunity of babesial infections. In addition, the antigens may possible be used in the development of new serologic techniques or vaccines. A babesia bigemina field isolate was purified by 4 rapid serial passages through 5 splenectomized calves within 6 1/2 days, and a stabilate of the isolated B. bigemina was established. The larval progeny of engorged female Boophilus microplus ticks were screened for the presence of Anaplasma marginale or Babesia spp. The nonifected ticks resulting from the screening were maintained primarily on noninfected splenectomized calves. Disease free guinea pigs were also utilized with only moderate success. Various stages of ticks were held without feeding in desiccator jars for periods of 1 to 2 months. Noninfected B. microplus ticks were successfully infected by placing them on calves inoculated intravenously with the B. bigemina stabilate. |
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