The present study was conducted on Ezemvelo Nature Reserve in the highveld grasslands of South Africa. The evidence for ecological separation between the black and blue wildebeest was investigated in an area with suboptimal habitat for both types of wildebeest. Habitat selection and separation of the black and blue wildebeest population were investigated at three main scales. A combination of logistic regression analysis, discriminant analysis and hypothesis testing techniques were used to determine whether habitat separation occurred between the black and blue wildebeest at the various scales. Seasonal, social group and weather influences on the habitat selection of both types of wildebeest were also investigated. Black and blue wildebeest showed resource partitioning in terms of habitat at the macro and mesoscales but not at the microscale. The preference for open areas by the black wildebeest and its more specialised territoriality were found to be the main driving factors contributing to the habitat separation of the two types of wildebeest. The population of black wildebeest was found to be decreasing while the blue wildebeest population was found to be increasing in the study area during the study period. Spatial overlap between the black and blue wildebeest was found to be low. Little evidence of interference interspecific competition between the black and blue wildebeest was found. It was, however, concluded that exploitative competition between the two types of wildebeest would be found in areas with low habitat heterogeneity. Ecological separation between the black and blue wildebeest was found to be incomplete. However, the coexistence of the black and blue wildebeest was deemed possible provided habitat heterogeneity in terms of the factors found to be important for habitat separation was high and population sizes were strictly monitored and actively controlled. Finally, a number of additional management recommendations for the black and blue wildebeest at Ezemvelo Nature Reserve and for other reserves confining both types of wildebeest together based on the results of this study were made. / Dissertation (MSc (Wildlife Management))--University of Pretoria, 2007. / Animal and Wildlife Sciences / MSc / unrestricted

Malignant catarrhal fever (MCF) is a mostly fatal lymphoproliferative disease in cattle, pigs, farmed deer, bison and a range of wild ungulates in zoos and game parks. The disease in domestic cattle is caused by either alcelaphine herpesvirus type 1 (AlHV–1) or ovine herpesvirus type 2 (OvHV–2). Both are members of the subfamily Gammaherpesvirinae. The major reservoir host of AlHV–1 is the blue wildebeest (Connochaetes taurinus), but it is generally accepted that the black wildebeest (Connochaetes gnou) is also a reservoir host. Sheep is the reservoir host for OvHV–2. These viruses are non-pathogenic in their natural hosts. No viral studies in the black wildebeest have been reported and as the carrier status of black wildebeest has not been documented, samples from 304 black wildebeest and 51 of their foetuses were collected for this purpose. Blood samples, including serum and blood collected in EDTA-coated collection tubes; cornea and spleen samples were collected from culled black wildebeest. Cornea and spleen samples were collected from foetuses during the culling operations. Blood samples, as above, were also collected from live animals during the capture of such animals. Tissue and EDTA-blood samples were tested by means of conventional and real-time polymerase chain reaction (PCR) assays for detection of a gammaherpesvirus similar or related to AlHV–1. Conventional PCR failed to produce any consistent results. Real-time PCR successfully amplified a region on the gene that codes for a transactivator protein, open reading frame (ORF) 50. Melting curves were generated to determine which samples were positive for a gammaherpesvirus. Only 15.8% of the animals tested positive with the real-time PCR assay. Ninety percent (90%) of the foetuses tested positive and suggests that, unlike sheep lambs, the virus is mainly transmitted in utero and soon after birth. Virus isolated from a black wildebeest calf of one week of age, was confirmed by electron microscopy and sequence analysis to be a gammaherpesvirus related to AlHV–1 and used as a positive control for the real-time PCR assays. Serum samples were tested by a direct competitive inhibition enzyme-linked immunosorbent assay (CI-ELISA) for group specific malignant catarrhal fever virus antibody. All the serum samples that were tested of culled and live animals, tested positive with the CI-ELISA. This indicates a persistent infection and a carrier status. / Dissertation (MMedVet)--University of Pretoria, 2007. / Veterinary Tropical Diseases / MMedVet / unrestricted

The treatment of tuberculosis (TB) is currently a challenge due to multi- and extensively drug resistant strains of Mycobacterium tuberculosis. Mycobacterium bovis and M. tuberculosis cause clinically indistinguishable tuberculosis in humans. Both M. bovis and M. tuberculosis have been isolated from humans and animals. Plant species contain antimicrobial compounds that may lead to new anti-TB drugs. To conduct in vitro antimycobacterial assays, it is important to include current clinical isolates as new strains of bacteria might be circulating under the ongoing climate change environment. The overall goal and objectives of this study were to isolate and characterize mycobacteria species from South Africa, to test some selected plant species of the Anacardiaceae family for antimycobacterial activity using some of the newly isolated and reference strains of mycobacteria followed by cytotoxicity evaluation of the most active plant species, and finally the isolation and characterization of at least one compound from the most active and least toxic plant. This study led to the discovery of a new isolate of Mycobacterium Avium Complex species from black wildebeest. Other non-tuberculous mycobacteria and M. bovis isolates were identified from other animal species. Five out of 15 plant species screened showed good activity against Mycobacterium species. Five antimycobacterial compounds were isolated from Searsia undulata, the most active plant species. Two out of the five compounds were identified, and one compound appears to be novel, but both compounds have been isolated for the first time from Searsia undulata. An incidental finding was the potential anticancer property of extracts of Searsia undulata. Recommended future activities include isolation and identification of more active compounds from Searsia undulata which were visible in bioautography analysis, as well as synergy evaluation of antimycobacterial activities of the different compounds with current anti-tubercular drugs. / Environmental Sciences / Ph. D. (Environmental Science)