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Between November 2002 and October 2006, blood samples were collected from 46 black rhinoceroses (Diceros bicornis) originating from various national parks and game reserves within South Africa. The samples were divided into two groups, based on the black rhinoceros subspecies from which they originated: twenty-eight (n = 28) of the samples originated from subspecies D. b. bicornis, and eighteen (n = 18) from subspecies D. b. minor. DNA was extracted; the V4 hypervariable region of the 18S rRNA gene amplified and subjected to the Reverse Line Blot (RLB) hybridization assay. The RLB results demonstrated the presence of either Theileria bicornis or Babesia bicornis in 9 of the 46 samples examined. A further three PCR products failed to hybridize with any of the Babesia or Theileria species-specific probes, and only hybridized with the Babesia/Theileria genus-specific probe, suggesting the presence of a novel species or variant of a species. Samples collected from black rhinoceroses originating from the more arid areas of South Africa, Tswalu Game Reserve and the old Vaalbos National Park, were found to be apparently free of T. bicornis and B. bicornis piroplasms. Based on these findings, it was concluded that B. bicornis and T. bicornis are relatively widespread in black rhinoceros populations in South Africa and pose a potential risk to the success of metapopulation management programs. Of the two black rhinoceros subspecies that occur in South Africa, D. b. bicornis is at greater risk due to their apparently Babesia/Theileria-naïve status in certain areas, when compared to the subspecies D. b. minor. Conservation managers need to carefully evaluate methods and procedures during the translocation of black rhinoceroses, especially when relocating from geographically and climatically diverse ecosystems and more so when dealing with the subspecies D. b. bicornis. Copyright / Dissertation (MSc (Veterinary Tropical Diseases))--University of Pretoria, 2009. / Veterinary Tropical Diseases / unrestricted

Orientador: Lucia Helena O'Dwyer / Resumo: Animais silvestres são considerados reservatórios para uma infinidade de patógenos transmitidos por ectoparasitas, dentre os quais Hepatozoon spp. e piroplasmas; e os ectoparasitas atuam como vetores desses micro-organismos. O presente estudo teve por objetivo investigar a ocorrência de Hepatozoon spp., piroplasmas e ectoparasitas em Nasua nasua e Didelphis spp. da região peri-urbana e urbana dos municípios de Botucatu, Palmital e São Paulo, além de identificar os ectoparasitas e caracterizar morfologicamente e molecularmente os hemoparasitas encontrados. Foram coletados ectoparasitas e amostras de sangue de 69 Didelphis albiventris, 11 Didelphis aurita e 83 N. nasua. Também, foram coletadas amostras de baço e fígado de dois N. nasua e de 25 D. albiventris, para análise histológica. Os carrapatos foram identificados e dissecados para pesquisa de oocistos de Hepatozoon spp. e alguns exemplares tiveram seu DNA extraído para verificar a presença de hemoparasitas. Para identificação dos hemoparasitas foram realizados esfregaços sanguíneos, a PCR, clonagem, e posterior sequenciamento das amostras. Primeiramente, Hepatozoon procyonis foi identificado em N. nasua. Dois carrapatos Amblyomma ovale, coletados em N. nasua, também foram positivos para Hepatozoon spp. Um espécimen foi positivo para H. procyonis e o outro para Hepatozoon sp. próximo de um haplótipo de Hepatozoon americanum. Um piroplasma próximo de Babesia sp. capybara foi detectado em Amblyomma sculptum, também coletado e... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Wild animals are considered reservoirs for several pathogens transmitted by ectoparasites, among which Hepatozoon spp., and piroplasms, and the ectoparasites are the vectors of these microorganisms. The present study aim to investigate the occurrence of Hepatozoon spp., piroplasms and ectoparasites in Nasua nasua and Didelphis spp., from peri-urban and urban regions of Botucatu, Palmital and São Paulo municipalities, besides to identify ectoparasites and characterize morphologically and molecularly the hemoparasites found. For this purpose, were collected ectoparasites and blood samples from 69 Didelphis albiventris, 11 Didelphis aurita e 83 N. nasua. In addition, tissue samples were collected from two N. nasua and 25 D. albiventris for histological analysis. Ticks were identified and dissected to recover oocysts of Hepatozoon spp. Some specimens of ticks had their DNA extracted for identification of hemoparasites. For parasitological diagnosis, blood smears were performed, for subsequent identification and morphometry of the parasites. The molecular diagnosis was performed by PCR or cloning and sequencing. First, we detected Hepatozoon procyonis infecting N. nasua. Amblyomma ovale collected on N. nasua was also infected by H. procyonis and by Hepatozoon sp. closely related to a Hepatozoon americanum haplotype. A piroplasm closely related to de Babesia sp. capybara was detected in Amblyomma sculptum collected also on N. nasua. We detected, for the first time, H. canis infecti... (Complete abstract click electronic access below) / Doutor