The in vitro cultivation of Babesia bigemina utilizing bovine cells in culture : a dissertation /
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| Other Authors: | , , , |
| Format: | Thesis Book |
| Language: | English |
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[College Station, Tex.] :
[Texas A&M University],
[1976]
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| Subjects: |
| Abstract: | ABSTRACT: Babesia bigemina in vitro cultivation experiments utilizing primary and continuous monolayer cultures were conducted. Experiments to infect normal non-infected cells by in vitro inoculation using fresh or stabilate B bigemina-infected blood as inoculum were conducted with primary monolayer cultures of bovine spleen, lymph node, hemal node, and fetal kidney and continuous monolayer cultures of African Green Monkey kidney cells Vero. When fresh infected blood was used as inoculum the B bigemina organisms dissociated from their host erythrocytes by day 2 and extracellular parasites were indentifiable for up to 5 days on the surface of the cultured cells. When stabilate preparations were used as inoculums the majority of the parasites remained intraerythrocytic with few extracellular parasites being observed. Babesia bigemina-infected erythrocytes present in the inoculum were observed for up to 14 days on the surface of the cultured cells; however, the parasites were degenerative and pyknotic in appearance. No differences were observed between the various types of cultured cells and there was no evidence that parasitic infection of culture cells or multiplication of organisms took place in the original cultures or subsequent subcultures. Experiments with primary monolayer cultures derived from B bigemina-infected calves were conducted with spleen, lymph node, hemal node and leucocyte cultures. Five days after culture seeding B bigemina organisms could be found only in splenic monolayer cultures and could be identified in such cultures for 11 days post culture. The number of B bigemina organisms decreased with time and there was no evidence that infection of cultured cells occurred or multiplication of the parasite took place. The subsequent 7 subcultures of the monolayer cultures did not demonstrate any evidence of being infected with B bigemina and no subcultures of detached cells suspended in media could be established. Babesia bigemina in vitro cultivation experiments utilzing erythrocyte maintenance suspension cultures were conducted. Experiments to infect normal non-infected erythrocytes maintained in suspension culture were conducted using fresh and stabilate infected blood preparations. In addition, B bigemina-infected blood was also placed in maintenance cultures. Before the erythrocyte maintenance procedures were improved a similar situation existed as with monolayer cultures. When fresh infected blood was used as inoculum or placed in maintenance culture the B bigemina became extraerythrocytic within 24 hours and failed to infect other non-infected erythrocytes. When stabilate preparations were used infected ghost erythrocytes were observed up to 2 days. Morphologically the B bigemina were degenerative. As the erythrocyte maintenance procedures improved infected erythrocytes were observed up to 4 days and infected erythrocytes held in maintenance culture 3 days were proven infective for a susceptible splenectomized calf. |
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| Item Description: | Vita. "Major Subject: Veterinary Microbiology." "Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of Doctor of Philosophy May 1976". |
| Physical Description: | ix, 82 leaves : illustrations ; 28 cm |
| Bibliography: | Includes bibliographical references (leaves 74-81). |