Comparative study of cervid Babesia isolates /
Isolations of Babesia spp. were made from wild Cervidae and
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1994.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=741965471&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Isolations of Babesia spp. were made from wild Cervidae and the parasites were established in vitro culture. The parasites isolated were Babesia odocoilei from white-tailed deer (Odocoileus virginianus), and uncharacterized Babesia spp. from an elk (Cervus elaphus canadensis) and a caribou (Rangifer tarandus cafibou). The three cervid isolates were morphologically closely similar to one another and were comparable in size to B. &vergens, which is classified as a "small" babesia. Like B. &vergens, the cervid parasites are often found situated in close proximity to the peripheral margin within the host erythrocyte. Relationships between the cervid isolates and B. divergens were compared on the basis of the following characteristics; (a) the ability of the parasites to utilize serum and erythrocytes from different hosts during in vitro culture, (b) the serological profiles seen in calves (Bos taurus and Cervus elaphus elaphus) after in vivo inoculation of the parasites, (c) the ultrastructural characteristics of the organisms and (d) the sequences of their small subunit ribosomal RNA (srRNA) genes. Slight differences were found among the cervid isolates in their ability to utilize alternate host serum and erythrocytes in vitro. Babesia divergens was able to propagate in bovine erythrocytes and serum whereas the cervid isolates were not. Post inocula tion calf sera showed strong homologous reactions in the immunofluorescent antibody test, although cross-reactions occurred as well. By transmission electron microscopy, Babesia odocoilei was found to have a feeding organelle not seen in the other isolates. The srRNA gene sequences of B. odocoilei and the isolates from the elk and caribou were identical. The cervid Babesia and B. divergens sequences were aligned with those already available from other Babesia and Theiletia spp. and phylogenetic trees were inferred from the alignment. These trees indicated that the cervid isolates were more closely related to B. divergens than to any other Babesia. Trees inferred by distance methods indicated that Babesia canis, classified as a "large" babesia, was the next most closely related among the Babesia spp. for which sequence data was available. The cervid Babesia isolates and B. divergens were paired together within the Babesia sensu stricto group in all of the phylogenetic trees. |
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| Item Description: | Vita. "Major subject: Veterinary Microbiology". |
| Physical Description: | xii, 105 leaves : illustrations ; 28 cm. |
| Bibliography: | Includes bibliographical references. |