Project description:The emergence and fast global spread of COVID-19 has presented one of the greatest public health challenges in modern times with no proven cure or vaccine. Africa is still early in this epidemic, therefore the extent of disease severity is not yet clear. We used a mathematical model to fit to the observed cases of COVID-19 in South Africa to estimate the basic reproductive number and critical vaccination coverage to control the disease for different hypothetical vaccine efficacy scenarios. We also estimated the percentage reduction in effective contacts due to the social distancing measures implemented. Early model estimates show that COVID-19 outbreak in South Africa had a basic reproductive number of 2.95 (95% credible interval [CrI] 2.83–3.33). A vaccine with 70% efficacy had the capacity to contain COVID-19 outbreak but at very higher vaccination coverage 94.44% (95% Crl 92.44–99.92%) with a vaccine of 100% efficacy requiring 66.10% (95% Crl 64.72–69.95%) coverage. Social distancing measures put in place have so far reduced the number of social contacts by 80.31% (95% Crl 79.76–80.85%). These findings suggest that a highly efficacious vaccine would have been required to contain COVID-19 in South Africa. Therefore, the current social distancing measures to reduce contacts will remain key in controlling the infection in the absence of vaccines and other therapeutics.
Project description:Esophageal squamous cell carcinoma (ESCC) is an aggressive cancer with one of the highest world incidences in the Eastern Cape region of South Africa. Several genome wide studies have been performed on ESCC cohorts from Asian countries, North America, Malawi and other parts of the world but none has been conducted on ESCC tumors from South Africa to date, where the molecular pathology and etiology of this disease remains unclear. We report here tumor associated copy number changes observed in 51 ESCC patients’ samples from the Eastern Cape province of South Africa. We extracted tumor DNA from 51 archived ESCC specimens and interrogated tumor associated DNA copy number changes using Affymetrix® 500K SNP array technology. The Genomic Identification of Significant Targets in Cancer (GISTIC) algorithm was applied to identify significant focal regions of gains and losses. Gains of the top recurrent cancer genes were validated by fluorescence in situ hybridization and their protein expression assessed by immunohistochemistry. Twenty-three significant focal gains were identified across samples. Gains involving the CCND1, MYC, EGFR and JAG1 loci recapitulated those described in studies on Asian and Malawian cohorts. The two most significant gains involved the chromosomal sub-bands 3q28, encompassing the TPRG1 gene and 11q13.3 including the CTTN, PPFIA1and SHANK2 genes. There was no significant homozygous loss and the most recurrent hemizygous deletion involved the B3GAT1 gene on chromosome11q25. Focal gains on 11q13.3 in 37% of cases (19/51), consistently involved CTTN and SHANK2 genes. Twelve of these cases (23,5%), had a broader region of gain that also included the CCND1, FGF19, FGF4 and FGF3 genes. SHANK2 and CTTN are co-amplified in several cancers, these proteins interact functionally together and are involved in cell motility. Immunohistochemistry confirmed both Shank2 (79%) and cortactin (69%) protein overexpression in samples with gains of these genes. In contrast, cyclin D1 (65%) was moderately expressed in samples with CCND1 DNA gain. This study reports copy number changes in a South African ESCC cohort and highlights similarities and differences with cohorts from Asia and Malawi. Our results strongly suggest a role for CTTN and SHANK2 in the pathogenesis of ESCC in South Africa.
2020-04-07 | GSE59105 | GEO
Project description:Complete genome sequence of novel polerovirus associated RNA infecting Pepper (Capsicum spp.) in South Africa
| PRJNA669445 | ENA
Project description:Genomic characterization of isolates from hospital effluents in KZN, South Africa
Project description:Only a few scattered groups with oral traditions of Khoe-San hunter-gatherer ancestry remain in southeastern Africa. We investigate genomic variation of remaining individuals from two South African groups with oral histories connecting them to eastern San groups, i.e., the San from Lake Chrissie and the Duma San of the uKhahlamba-Drakensberg. Using ~2.2 million genetic markers, combined with comparative published datasets, we show that the Lake Chrissie San have genetic ancestry from both Khoe-San (likely the ||Xegwi San) and Bantu-speakers. Specifically, we found that the Lake Chrissie San are closely related to current southern San groups (i.e. the Karretjie People). Duma San individuals, on the other hand, were genetically similar to southeastern Bantu speakers from South Africa. Samples were genotyped on the Illumina Omni2.5M (HumanOmni25-8v1-2_A1) SNP chip. Results were analyzed using the software GenomeStudio 2011.1 and the data were exported to Plink format, aligned to Human Genome build version 37.
Project description:Puccinia graminis f. sp. tritici is the cause of wheat stem rust. A microarray was designed from genes predicted from the P. graminis f. sp. tritici genome assembly, and gene expression measured for four conditions which include wheat or barley infecting growth stages initiated by urediniospores. mRNA was prepared from fresh urediniospores, uredinospores germinated for 24 hr, wheat seedlings infected with urediniospores for 8 days, and barley seedlings infected with urediniospores for 8 days. The asexual uredinial infection cycle on wheat produces additional urediniospores, which can start new cycles of wheat infection and are readily spread by aerial transport. This expression data is further described in Duplessis et al, Obligate Biotrophy Features Unraveled by the Genomic Analysis of the Rust Fungi, Melampsora larici-populina and Puccinia graminis f. sp. tritici
2010-12-31 | GSE25020 | GEO
Project description:Genomic characterization of soybean blotchy mosaic virus, a cytorhabdovirus from South Africa.