Brenda A. Robson
Stellenbosch University
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Featured researches published by Brenda A. Robson.
Journal of General Virology | 1998
E J Van Rensburg; Susan Engelbrecht; J. M. Mwenda; J.D. Laten; Brenda A. Robson; T Stander; G K Chege
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.
AIDS | 2002
Estrelita Janse van Rensburg; Tracey-Lee Smith; Michelle Zeier; Brenda A. Robson; Candice C. Sampson; Florette K. Treurnicht; Susan Engelbrecht
The publisher prohibits open access to the full text of this Research Letter. If you require the full text, please contact the Collection Administrator, or access the item via the e-journal collection.
Journal of Acquired Immune Deficiency Syndromes | 1996
Susan Engelbrecht; E J Van Rensburg; Brenda A. Robson
We report on the subtyping of South African primate T-cell lymphotropic virus type I (PTLV-I) strains by investigating the LTR region using sequence analysis and restriction fragment length polymorphism (RFLP) techniques. DNA from either uncultured peripheral blood mononuclear cells (PBMCs); cultured PBMC or cell lines of eight human T-cell lymphotropic virus type I (HTLV-I); and two simian T-cell lymphotropic virus type I (STLV-I) strains (Cercopithecus aethiops pygerythrus) were amplified by polymerase chain reaction (PCR), cloned, and sequenced. The samples originated from different geographical regions in South Africa. Phylogenetic relationships were estimated using the neighbor-joining method. The South African HTLV-I strains were of Cosmopolitan origin and similar to each other. RFLP analysis confirmed this subtyping. A divergence of 0.3 to 1.6% between the Cosmopolitan strains was observed, while the divergence between the HTLV-I and STLV-I strains ranged from 6.3 to 7%. The STLV-I strains were closely related to that of a chimpanzee, providing evidence of interspecies transmission.
AIDS Research and Human Retroviruses | 1999
Susan Engelbrecht; Irene Koulinska; Tracey-Lee Smith; Brenda A. Robson; Jorge Barreto; Estrelita Janse van Rensburg
The publisher does not allow open access to the full text of this sequence note. If you however need access to the full text, please contact the Collection Administrator, or access the item via the e-journal collection.
AIDS Research and Human Retroviruses | 1999
Estrelita Janse van Rensburg; Susan Engelbrecht; Brenda A. Robson; Daudi K. Langat; Mohamed Isahakia; Jason Mwenda
781 H UM AN T CELL LEU KEM IA/lymphotropic virus type I (HTLVI) strains have a worldwide distribution and are characterized by the genetic stability of their genome and their limited horizontal transmission. Simian T cell leukemia/lymphotropic virus type I (STLV-I) strains have been found in Old World nonhuman primates in Africa and Asia. Together, these two virus groups are referred to as primate T lymphotropic viruses (PTLVs) and have been found in all three Old World African primate families: the Cercopithecidae, 2±4 the Pongidae, and the Hominidae. These viruses cannot be separate d into distinct phyloge netic lineages according to the fam ilies or species of origin, but rather accordi ng to geographical regions , which suggest s multiple interspe cies transm issions in the past. Although uncertain, it is thought that the origina l virus infected nonhu man simian ancesto rs that eventua lly infected humans. 2 Understan ding the sequence diversit y among STLV-I strains may therefor e provide valuable insight into the evolutio n of the PTLV-I group. In this study, we analyze d the HTLV-I sequenc e of 13 nonhum an primates, using HTLV-I cross-r eacting antibod ies provide d with the HTLV-I Serodia particle aggluti nation assay (Fujirebio , Tokyo, Japan). The animals were either colony born (Institu te of Primate Research [IPR], Nairobi, Kenya) or trapped in Kibwezi (eastern Kenya) and in Gilgil and Namanga (Rift Valley Province) . The animals include d four vervet monkeys (Cercopit hecus aethiop s pygerythrus ), two lowland Sykes monkeys (Cercopit hecus mitis), and seven olive baboons (Papio anubis ) (Table 1). We have focused on the diverge nt long terminal repeat (LTR) region because it is more inform ative for sequence analysi s and subtyping, and because of the availab ility of inform ation on other PTLV-I LTR sequenc es. DNA was isolated from peripheral blood mononuclear cells (PBMCs) using a QiaAmp blood kit (Qiagen GmbH, Hilden, Germany). The LTR region was amplified by the polymerase chain reaction (PCR) with primer pairs HFL1/HFL6 and HFL5/HFL6, as described. 11 PCR products were cloned using the PCR-Script SK( 1 ) cloning kit (Stratagene, La Jolla, CA) according to the manufacturer instructions. Sequencing was performed using the Applied Biosystem s model 373 automatic DNA sequencer (Applied Biosystems/Perkin-Elmer , Foster City, CA). Nucleotide sequences were aligned with CLUSTAL V together with reference sequences from the GenBank database. Kimura distance calculation, 13 bootstrap analysis, 14 and tree construction were done with the TREECON software package. Nucleotide sequences were submitted to GenBank under accession numbers AF117282±AF117294. Comparison of the LTR region of the strains revealed that the elements that are critical for viral gene expression were well conserved. No nucleotide changes were observed in the polyadenylation signal (AATAAA), the TATA box (TATAAA), and the splice donor site (TAGGTAA). In the tree containing the LTR sequence (Fig. 1), STLV and HTLV-I clusters were identified as containing sequences representative of many different subtypes.
The Lancet | 1989
W.B. Becker; Susan Engelbrecht; M.L.B. Becker; C. Piek; Brenda A. Robson; Lucille Wood
Journal of Medical Virology | 2002
Florette K. Treurnicht; Tracey-Lee Smith; Susan Engelbrecht; Matilda Claassen; Brenda A. Robson; Michelle Zeier; Estrelita Janse van Rensburg
AIDS | 2000
Orth H; Susan Engelbrecht; Mark F. Cotton; Brenda A. Robson; Smith T-L; Schaaf Hs; Leibrandt B; Dobbels E; Janse Van Rensburg E
Anticancer Research | 2000
E J Van Rensburg; W.F.P. Van Heerden; Brenda A. Robson; T. J. P. Swart; Susan Engelbrecht
Anticancer Research | 2001
Van Heerden Wfp; Swart Tjp; Brenda A. Robson; Smith T-L; Susan Engelbrecht; Van Heerden Mb; Janse Van Rensburg E; Huebner K