Media & Communication (Estrelita Janse van Rensburg)

Permanent URI for this collectionhttp://hdl.handle.net/2263/2871

Digital repository of research related output [excluding research articles] e.g. letters, sequence notes, editorials, correspondence and related information of Prof Estrelita Janse van Rensburg. Additional media & communication related information of Prof Estrelita Janse van Rensburg may also be included in this collection.

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Simian immunodeficiency viruses (SIVs) from eastern and southern Africa : detection of a SIVagm variant from a chacma baboon
(American Society for Microbiology, 1998) Janse van Rensburg, Estrelita; Engelbrecht, Susan; Mwenda, Jason M.; Laten, Janetta D.; Robson, Brenda A.; Stander, Tania; Chege, Gerald K.; estrelita@up.ac.za
Simian immunodeficiency viruses (SIVs) have been shown to infect many old world African primate species. Thus far, no work has been published on southern African primates. In this study we investigated the genetic diversity between SIV strains from Kenyan and South African vervets (Cercopithecus aethiops pygerythrus). We amplified and sequenced a 1113 bp region of the env gene. Phylogenetic analysis of these sequences showed that all strains clustered with members of the vervet subgroup of SIVagm. The SIVs from South African vervets differed by 7% from each other and by 8–14% from the Kenyan SIV strains, while the Kenyan SIV strains differed by 10–21% from SIVagm of other east African vervets. We also isolated and sequenced, for the first time, a SIV strain from a healthy chacma baboon (Papio ursinus), caught in South Africa. Phylogenetic analysis of the env region showed the virus to be closely related to the South African vervet SIV strains, while analysis of its pol region confirmed the virus to be a SIVagm variant.
Subtyping of human t cell lymphotropic virus type I from tropical spastic paraparesis/HTLV-associated myelopathy patients in Mozambique
(Mary Ann Liebert, 1999-01) Engelbrecht, Susan; Koulinska, Irene; Smith, Tracey-Lee; Robson, Brenda A.; Barreto, Jorge; Janse van Rensburg, Estrelita
Absence of human herpesvirus-8 DNA in Kaposi's sarcoma following postmastectomy lymphoedema
(Blackwell, 2000-05) Du Plessis, D.G.; Schneider, Johann W.; Treurnicht, Florette K.; Engelbrecht, Susan; Janse van Rensburg, Estrelita
No abstract available
Characterization and phylogenetic analysis of South African HIV-1 subtype C accessory genes
(Mary Ann Liebert, 2001-05) Scriba, Thomas Jens; Treurnicht, Florette K.; Zeier, Michelle D.; Engelbrecht, Susan; Janse van Rensburg, Estrelita
To acquire new knowledge about the genetic diversity and potential impact on vaccine strategies of HIV-1 subtype C in South Africa, we have characterized the vif, vpr, and vpu genes of 15 isolates. Phylogenetic analysis of the genomic fragment encompassing these genes revealed subtype C subclusters, suggesting close relatedness with subtype C strains from other geographic locations and excluded isolation of South African strains. The putative T155 phosphorylation site in the C terminal of Vif was absent in all subtype C sequences. Variation in the predicted amino acid sequences of the three genes further showed strong correlation with other subtype C sequences.
Genetic analysis of the complete gag and env genes of HIV type 1 subtype C primary isolates from South Africa
(Mary Ann Liebert, 2001-11) Engelbrecht, Susan; De Villiers, Tania; Sampson, Candice C.; Zur Megede, Jan; Barnett, Susan W.; Janse van Rensburg, Estrelita
South Africa has one of the fastest growing HIV-1 epidemics, with an estimated 4.7 million people infected. To better understand the genetic diversity of this epidemic and its potential impact on vaccine development, we have cloned and sequenced the complete gag and env genes of 13 primary virus isolates. Phylogenetic analysis of our sequences and 69 complete env genes from the Los Alamos and GenBank databases revealed multiple subclusters within subtype C. The V3 loop region was relatively conserved in all our strains when compared with other subtypes, but the region immediately downstream was highly variable. No intersubtype recombinant forms were observed when comparing the gag and env sequences. Characterization of the complete gag and env genes enabled us to select specific strains for further vaccine development.
Change in co-receptor usage of current South African HIV-1 subtype C primary isolates
(Lippincott Williams and Wilkins, 2002-12-06) Janse van Rensburg, Estrelita; Smith, Tracey-Lee; Zeier, Michelle D.; Robson, Brenda A.; Sampson, Candice C.; Treurnicht, Florette K.; Engelbrecht, Susan
Novel evolutionary analyses of full-length HIV type 1 subtype C molecular clones from Cape Town South Africa
(Mary Ann Liebert, 2002-11) Zur Megede, Jan; Engelbrecht, Susan; De Oliveira, Tulio; Scriba, Thomas Jens; Janse van Rensburg, Estrelita; Barnett, Susan W.; Cassol, Sharon
Understanding the origin, distribution, and evolving dominance of HIV-1 subtype C strains is an important component in the design and evaluation of a globally effective AIDS vaccine. To better understand subtype C viruses, we constructed complete molecular clones of primary, CCR-5-using isolates from South Africa and analyzed the molecular phylogenies of these clones using best fitting evolutionary substitution models. Analyses were performed on three full-length sequences, and on the individual genes. All clones were nonrecombinant, and although two of three had open reading frames and intact splice sites, they were not infectious. At the genomic level, the models demonstrated the increasing variability of subtype C in South Africa. At the subgenomic level, they revealed marked differences in the evolutionary patterns of individual genes, a finding that suggests that the genes are under different selective pressures and constraints. These data underscore the dynamic nature of the subtype C epidemic and emphasize the need for continuous monitoring of local strains.

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