Repository logo
  • English
  • Català
  • Čeština
  • Deutsch
  • Español
  • Français
  • Gàidhlig
  • Italiano
  • Latviešu
  • Magyar
  • Nederlands
  • Polski
  • Português
  • Português do Brasil
  • Suomi
  • Svenska
  • Türkçe
  • Tiếng Việt
  • Қазақ
  • বাংলা
  • हिंदी
  • Ελληνικά
  • Yкраї́нська
  • Log In
    or
    New user? Click here to register.Have you forgotten your password?
Repository logo
  • Communities & Collections
  • All of NRU
  • English
  • Català
  • Čeština
  • Deutsch
  • Español
  • Français
  • Gàidhlig
  • Italiano
  • Latviešu
  • Magyar
  • Nederlands
  • Polski
  • Português
  • Português do Brasil
  • Suomi
  • Svenska
  • Türkçe
  • Tiếng Việt
  • Қазақ
  • বাংলা
  • हिंदी
  • Ελληνικά
  • Yкраї́нська
  • Log In
    or
    New user? Click here to register.Have you forgotten your password?
  1. Home
  2. Browse by Author

Browsing by Author "Mwesigwa, Savannah"

Now showing 1 - 14 of 14
Results Per Page
Sort Options
  • Loading...
    Thumbnail Image
    Item
    Chromosomal and plasmid-encoded virulence and multidrug resistance of Escherichia coli ST58/24 infecting a 2-year-old sickle cell patient with sepsis in Kampala Uganda, East Africa
    (Elsevier Ltd, 2024-05) Maghembe, Reuben S; Magulye, Maximilian A.K; Eilu, Emmanuel; Sekyanzi, Simon; Mwesigwa, Savannah; Katagirya, Eric
    Sepsis and drug resistance represent a complex of the most common global causes of mortality in intensive care units (ICUs) especially among patients with comorbidities. Extraintestinal pathogenic Escherichia coli (ExPEC) strains are highly implicated in systemic infections, with multidrug resistance exacerbating the risk of chronic conditions and patient mortality. The diversity of virulence and evolution of multidrug resistance are yet to be fully deciphered. In this work, we aimed at unveiling the pathogens and their genomic determinants of virulence and drug resistance relevant to increased sepsis in a sickle cell child admitted to ICU. From a rectal swab, we isolated a strain of E. coli from the patient and phenotypically tested it against a panel of selected beta lactams, fluoroquinolones, macrolides, aminoglycosides and colistin. We then sequenced the entire genome and integrated multiple bioinformatic pipelines to divulge the virulence and multidrug resistance profiles of the isolate. Our results revealed that the isolate belongs to the sequence type (ST) 58/24, which (ST58), is a known ExPEC. With the use of PathogenFinder, we were able to confirm that this isolate is a human pathogen (p = 0.936). The assembled chromosome and two plasmids encode virulence factors related to capsule (antiphagocytosis), serum survival and resistance, type 6 secretion system (T6SS), multiple siderophores (iron acquisition), and biosynthetic gene clusters for polyketides and nonribosomal peptides exhibiting host cell damaging activity in silico. The genome also harbors multidrug resistance genotypes including extended spectrum beta lactamase (ESBL) genes such as blaTEM-1A/B, sulfonamide resistance genes sul1/2, fluoroquinolone resistance genes dfrA5 and nonsynonymous mutations of the gene pmrB, conferring intrinsic colistin resistance. Conclusively, this pathogen holds the potential to cause systemic infection and might exacerbate sickle cell anemia in the patient. The virulence and multidrug resistance profiles are encoded by both the chromosome and plasmids. Genomic surveillance of pathogens with multidrug resistance among patients with commodities is crucial for effective disease management. [Display omitted] •Extraintestinal pathogenic Escherichia coli (ExPEC) causes blood stream infections.•The genome carries genes that enhance its dissemination and blood stream survival.•With multidrug resistance, it can exacerbate sepsis in patients with commodities.
  • Loading...
    Thumbnail Image
    Item
    The Collaborative African Genomics Network (CAfGEN): Applying Genomic technologies to probe host factors important to the progression of HIV and HIV-tuberculosis infection in sub-Saharan Africa [version 1; referees: awaiting peer review]
    (AAS open research, 2018) Mboowa, Gerald; Mwesigwa, Savannah; Katagirya, Eric; Retshabile, Gaone; Mlotshwa, Busisiwe C.; Williams, Lesedi; Kekitiinwa, Adeodata; Kateete, David; Wampande, Eddie; Wayengera, Misaki; Nsangi Kintu, Betty; Kisitu, Grace P.; Kyobe, Samuel; Brown, Chester W.; Hanchard, Neil A.; Mardon, Graeme; Joloba, Moses; Anabwani, Gabriel; Pettitt, Ed; Tsimako-Johnstone, Masego; Kasvosve, Ishmael; Maplanka, Koketso; Mpoloka, Sununguko W.; Hlatshwayo, Makhosazana; Matshaba, Mogomotsi
    The Human Heredity and Health in Africa consortium (H3Africa) was conceived to facilitate the application of genomics technologies to improve health across Africa. Here, we describe how the Collaborative African Genomics Network (CAfGEN) of the H3Africa consortium is using genomics to probe host genetic factors important to the progression of HIV and HIV-tuberculosis (TB) coinfection in sub-Saharan Africa. Methods: CAfGEN is an H3Africa collaborative centre comprising expertise from the University of Botswana; Makerere University; Baylor College of v
  • Loading...
    Thumbnail Image
    Item
    The collaborative African genomics network training program: a trainee perspective on training the next generation of African scientists
    (Genetics in Medicine, 2017) Mlotshwa, Busisiwe C.; Mwesigwa, Savannah; Mboowa, Gerald; Williams, Lesedi; Retshabile, Gaone; Kekitiinwa, Adeodata; Wayengera, Misaki; Kyobe, Samuel; Brown, Chester W.; Hanchard, Neil A.; Mardon, Graeme; Joloba, Moses; Anabwani, Gabriel; Mpoloka, Sununguko W.
    The Collaborative African Genomics Network (CAf- GEN) aims to establish sustainable genomics research programs in Botswana and Uganda through long-term training of PhD students from these countries at Baylor College of Medicine. Here, we present an overview of the CAfGEN PhD training program alongside trainees’ perspectives on their involvement. Background: Historically, collaborations between high-income countries (HICs) and low- and middle-income countries (LMICs), or North–South collaborations, have been criticized for the lack of a mutually beneficial distribution of resources and research findings, often undermining LMICs. CAfGEN plans to address this imbalance in the genomics field through a program of technology and expertise transfer to the participating LMICs. Methods: An overview of the training program is presented. Trainees from the CAfGEN project summarized their experiences, looking specifically at the training model, benefits of the program, challenges encountered relating to the cultural transition, and program outcomes after the first 2 years. Conclusion: Collaborative training programs like CAfGEN will not only help establish sustainable long-term research initiatives in LMICs but also foster stronger North–South and South–South networks. The CAfGEN model offers a framework for the development of training programs aimed at genomics education for those for whom genomics is not their “first language.”
  • Loading...
    Thumbnail Image
    Item
    Exome Sequencing Reveals a Putative Role for HLA-C*03:02 in Control of HIV-1 in African Pediatric Populations
    (Frontiers in Genetics, 2021) Kyobe, Samuel; Mwesigwa, Savannah; Kisitu, Grace P.; Farirai, John; Katagirya, Eric; Mirembe, Angella N.; Ketumile, Lesego; Wayengera, Misaki; Ashaba Katabazi, Fred; Kigozi, Edgar; Wampande, Edward M.; Retshabile, Gaone; Mlotshwa, Busisiwe C.; Williams, Lesedi; Morapedi, Koketso; Kasvosve, Ishmael; Kyosiimire-Lugemwa, Jacqueline; Nsangi, Betty; Tsimako-Johnstone, Masego; Brown, Chester W.; Joloba, Moses; Anabwani, Gabriel; Bhekumusa, Lukhele; Mpoloka, Sununguko W.; Mardon, Graeme; Matshaba, Mogomotsi; Kekitiinwa, Adeodata; Hanchard, Neil A.
    Human leucocyte antigen (HLA) class I molecules present endogenously processed antigens to T-cells and have been linked to differences in HIV-1 disease progression. HLA allelotypes show considerable geographical and inter-individual variation, as does the rate of progression of HIV-1 disease, with long-term non-progression (LTNP) of disease having most evidence of an underlying genetic contribution. However, most genetic analyses of LTNP have occurred in adults of European ancestry, limiting the potential transferability of observed associations to diverse populations who carry the burden of disease. This is particularly true of HIV-1 infected children. Here, using exome sequencing (ES) to infer HLA allelotypes, we determine associations with HIV- 1 LTNP in two diverse African pediatric populations. We performed a case-control association study of 394 LTNPs and 420 rapid progressors retrospectively identified from electronic medical records of pediatric HIV-1 populations in Uganda and Botswana. We utilized high-depth ES to perform high-resolution HLA allelotyping and assessed evidence of association between HLA class I alleles and LTNP. Sixteen HLA alleles and haplotypes had significantly different frequencies between Uganda and Botswana, with allelic differences being more prominent in HLA-A compared to HLA-B and C allelotypes. Three HLA allelotypes showed association with LTNP, including a novel association in HLA-C (HLA-B 57:03, aOR 3.21, Pc = 0.0259; B 58:01, aOR 1.89, Pc = 0.033; C 03:02, aOR 4.74, Pc = 0.033). Together, these alleles convey an estimated population attributable risk (PAR) of non-progression of 16.5%. We also observed novel haplotype associations with HLA-B 57:03-C 07:01 (aOR 5.40, Pc = 0.025) and HLA-B 58:01- C 03:02 (aOR 4.88, Pc = 0.011) with a PAR of 9.8%, as well as a previously unreported independent additive effect and heterozygote advantage of HLA-C 03:02 with B 58:01 (aOR 4.15, Pc = 0.005) that appears to limit disease progression, despite weak LD (r2 = 0.18) between these alleles. These associations remained irrespective of gender or country. In one of the largest studies of HIV in Africa, we find evidence of a protective effect of canonical HLA-B alleles and a novel HLA-C association that appears to augment existing HIV-1 control alleles in pediatric populations. Our findings outline the value of using multi-ethnic populations in genetic studies and offer a novel HIV-1 association of relevance to ongoing vaccine studies.
  • Loading...
    Thumbnail Image
    Item
    Genetic Diversity and Acquired Drug Resistance Mutations Detected by Deep Sequencing in Virologic Failures among Antiretroviral Treatment Experienced Human Immunodeficiency Virus-1 Patients in a Pastoralist Region of Ethiopia
    (Infection and Drug Resistance, 2021) Tachbele, Erdaw; Kyobe, Samuel; Ashaba Katabazi, Fred; Kigozi, Edgar; Mwesigwa, Savannah; Joloba, Moses; Messele, Alebachew; Amogne, Wondwossen; Legesse, Mengistu; Pieper, Rembert; Ameni, Gobena
    This study was conducted to investigate the drug resistance mutations and genetic diversity of HIV-1 in ART experienced patients in South Omo, Ethiopia. Patients and Methods: A cross-sectional study conducted on 253 adult patients attending ART clinics for ≥6 months in South Omo. Samples with VL ≥1000 copies/ mL were considered as virological failures (VF) and their reverse transcriptase gene codons 90–234 were sequenced using Illumina MiSeq. MinVar was used for the identification of the subtypes and drug resistance mutations. Phylogenetic tree was constructed by neighbor-joining method using the maximum likelihood model. Results: The median duration of ART was 51 months and 18.6% (47/253) of the patients exhibited VF. Of 47 viraemic patients, the genome of 41 were sequenced and subtype C was dominant (87.8%) followed by recombinant subtype BC (4.9%), M-09- CPX (4.9) and BF1 (2.4%). Of 41 genotyped subjects, 85.4% (35/41) had at least one ADR mutation. Eighty-one percent (33/41) of viraemic patients harbored NRTI resistance mutations, and 48.8% (20/41) were positive for NNRTI resistance mutations, with 43.9% dual resistance mutations. Among NRTI resistance mutations, M184V (73.2%), K219Q (63.4%) and T215 (56.1%) complex were the most mutated positions, while the most common NNRTI resistance mutations were K103N (24.4%), K101E, P225H and V108I 7.5% each. Active tuberculosis (aOR=13, 95% CI= 3.46–29.69), immunological failure (aOR=3.61, 95% CI=1.26–10.39), opportunistic infections (aOR=8.39, 95% CI= 1.75–40.19), and poor adherence were significantly associated with virological failure, while rural residence (aOR 2.37; 95% CI: 1.62–9.10, P= 0.05), immunological failures (aOR 2.37; 95% CI: 1.62–9.10, P= 0.05) and high viral load (aOR 16; 95% CI: 5.35 51.59, P <0.001) were predictors of ADR mutation among the ART experienced and viraemic study subjects. Conclusion: The study revealed considerable prevalence of VF and ADR mutation with the associated risk indicators. Regular virological monitoring and drug resistance genotyping methods should be implemented for better ART treatment outcomes of the nation.
  • Loading...
    Thumbnail Image
    Item
    Molecular characterization and phylogenetic study of African swine fever virus isolates from recent outbreaks in Uganda (2010–2013)
    (Virology journal, 2013) Kalenzi Atuhaire, David; Afayoa, Mathias; Ochwo, Sylvester; Mwesigwa, Savannah; Okuni, Julius Boniface; Olaho-Mukani, William; Ojok, Lonzy
    African swine fever (ASF) is a highly lethal and economically significant disease of domestic pigs in Eastern Africa particularly in Uganda where outbreaks regularly occur. Sequence analysis of variable genome regions have been extensively used for molecular epidemiological studies of African swine fever virus (ASFV) isolates. By combining p72, P54 and pB602L (CVR), a high level resolution approach is achieved for viral discrimination. The major aim of this study therefore, was to investigate the genetic relatedness of ASF outbreaks that occurred between 2010 and 2013 in Uganda to contribute to the clarification of the epidemiological situation over a four year period. Methods: Tissue samples from infected domestic pigs associated with an ASF outbreak from 15 districts in Uganda were confirmed as being infected with ASFV using a p72 gene-based polymerase chain reaction amplification (PCR) assay recommended by OIE. The analysis was conducted by genotyping based on sequence data from three single copy ASFV genes. The E183L gene encoding the structural protein P54 and part of the gene encoding the p72 protein was used to delineate genotypes. Intra-genotypic resolution of viral relationships was achieved by analysis of tetramer amino acid repeats within the hypervariable CVR of the B602L gene. Results: Twenty one (21) ASF outbreaks were confirmed by the p72 ASF diagnostic PCR, however; only 17 isolates were successfully aligned after sequencing. Our entire isolates cluster with previous ASF viruses in genotype IX isolated in Uganda and Kenya using p72 and P54 genes. Analysis of the CVR gene generated three sub-groups one with 23 tetrameric amino acid repeats (TRS) with an additional CAST sequence, the second with 22 TRS while one isolate Ug13. Kampala1 had 13 TRS. Conclusion: We identified two new CVR subgroups different from previous studies. This study constitutes the first detailed assessment of the molecular epidemiology of ASFV in domestic pigs in the different regions of Uganda.
  • Loading...
    Thumbnail Image
    Item
    Molecular characterization of African swine fever virus in apparently healthy domestic pigs in Uganda
    (African Journal of Biotechnology,, 2014) Kalenzi Atuhaire, David; Ochwo, Sylvester; Afayoa, Mathias; Mwesigwa, Savannah; Mwiine, Frank Norbert; Okuni, Julius Boniface; Olaho-Mukani, William; Ojok, Lonzy
    African swine fever (ASF) is a highly lethal and economically significant disease of domestic pigs in Uganda where outbreaks regularly occur. There is neither a vaccine nor treatment available for ASF control. Twenty two African swine fever virus (ASFV) genotypes (I - XXII) have been identified based on partial sequencing of the C-terminus of the major capsid protein p72 encoded by the B646L gene. The majority of previously characterized Ugandan ASFV strains belong to genotype IX. The major aim of the current study was to determine the ASFV genotypes among asymptomatic slaughter pigs at Wambizi slaughterhouse and in some parts of the country where surveillance was done. Three discrete regions of the ASFV were analysed in the genomes of viruses detected in asymptomatic domestic pigs. The analysis was conducted by genotyping based on sequence data from three single copy ASFV genes. The E183L gene encoding the structural protein P54 and part of the gene encoding the p72 protein were used to delineate genotypes, before intra-genotypic resolution of viral relationships by analysis of tetramer amino acid repeats within the hypervariable central variable region (CVR) of the B602L gene. All the ASF viruses obtained from this study clustered with previous viruses in genotype IX based on analysis of the p72 and P54 genes. Analysis of the CVR gene grouped the viruses in three different subgroups; 13, 23 and 25. Only one genotype is circulating in Uganda among asymptomatic domestic pigs and it is the same virus causing outbreaks in the country and parts of neighbouring Kenya.
  • Loading...
    Thumbnail Image
    Item
    Prevalence and determinants of virological failure among adult antiretroviral treatment experienced HIV-1 patients in South Omo, Ethiopia
    (Ethiopian Journal of Health Development, 2022) Tachbele, Erdaw; Kyobe, Samuel; Ashaba, Fred; Kigozi, Edgar; Mwesigwa, Savannah; Joloba, Moses; Amogne, Wondwossen; Legesse, Mengistu; Peiper, Rembert; Ameni, Gobena
    Virological failure (VF) is a challenge which hinders the success of the antiretroviral treatment (ART) program. Although viral load is the preferred method used to detect and confirm treatment failure, research into its prevalence and determinants is limited. Objective: This study was conducted to determine the prevalence of virological failure and its determinants among HIV-1 infected adults, who experienced first line ART in South Omo, Ethiopia. Methods: A cross-sectional study was conducted on patients attending ART clinics at Jinka Zonal hospital and four rural health centers found in South Omo. A total of 253 adult patients who were on ART for ≥ 6 months were recruited sequentially from January 2015- December 2016. In addition to the socio-demographic and clinical data, 10 ml of blood was collected for the CD4+ T cell count and the viral load measurements. CD4+T cell count was conducted using the FACS Caliber flow cytometer and the viral load was estimated using a quantitative real time reverse transcriptase polymerase chain reaction (qRT-PCR). Samples with a VL ≥1000 copies/mL were considered as virological failure. Logistic regression analysis was used to identify correlates of virological failure. Results: The median duration of ART was 51 months. About 61% of the participants were females with a mean age of 33.5 years. Majority of the participants (70%) were taking the tenofovir (TDF) based ART, while 30% were taking a zidovudine (AZT) based regimen. Majority (71.9%) of the participants started ART in WHO III/IV stage, with a median base line CD4 count of 239 cell/μL. More than 40% of the participants reported poor ART adherence, and 11% had immunological failure. From a total of 253 patients, 206(81.4 %) [95%CI: 76.7-86.2] had viral suppression, while 47 (18.6%) [95%CI: 13.8-23.3] had virological failure with a mean viral load of 185,506 copies/mL (95%CI: 39083-408100). None of the virological failures were switched to second line ART. According to the multivariate logistic analysis, active tuberculosis (aOR=13, 95% CI= 3.46-29.69), immunological failure (aOR=3.61, 95% CI=1.26-10.39), opportunistic infections (aOR=8.39, 95% CI= 1.75-40.19), and poor adherence were significantly associated with VF among the study participants. Conclusion: The study revealed a considerable prevalence of virological failures with the associated risk indicators. Based on the results and the difficulty faced, of being unable to place patients who were treatment resistant in second line ART, indicates that immunological and clinical criteria are poor biomarkers of drug switching. Hence, regular virological monitoring should be implemented for better ART treatment outcomes in individuals who are HIV positive.
  • Loading...
    Thumbnail Image
    Item
    Prevalence of African swine fever virus in apparently healthy domestic pigs in Uganda
    (BMC veterinary research, 2013) Atuhaire, David Kalenzi; Afayoa, Mathias; Ochwo, Sylvester; Mwesigwa, Savannah; Mwiine, Frank Norbert; Okuni, Julius Boniface; Mukani, William Olaho; Ojok, Lonzy
    African swine fever (ASF) is a contagious viral disease which can cause up to 100% mortality among domestic pigs leading to serious socio-economic impact on people’s livelihoods. ASF is endemic in Uganda and there is paucity of information on the epidemiology of the disease. The major aim of this study was to determine the seroprevalence and prevalence of African swine fever virus (ASFV) in apparently healthy slaughter pigs at Wambizi slaughterhouse in Kampala city, Uganda. We also estimated the presence of ASFV antibodies and circulating viral antigens in pigs from selected districts of Uganda during targeted surveillance. We analysed 540 and 181 blood samples collected from slaughter pigs and pigs from targeted surveillance districts respectively.The prevalence of ASFV in slaughter pigs was 52.96% (95% CI, 48.75-57.14) and 11.5% (95% CI, 9.06-14.45) by ELISA and PCR respectively. In surveillance districts, the proportion of ASFV positive pigs was 53.59% (95% CI, 46.33-60.71) and 0.55% (95% CI, 0.1-3.06) by ELISA and PCR respectively.The study has found out a high seroprevalence of ASFV antibodies in apparently healthy slaughter pigs and also a high proportion of ASFV antibody seropositive pigs in surveyed districts in Uganda indicating exposure to ASFV. However, there was a lower prevalence of ASFV infection implying that there could be low virulent strains of ASFV circulating in domestic pigs in Uganda which requires further investigation.
  • Loading...
    Thumbnail Image
    Item
    Prevalence of arps10, fd, pfmdr-2, pfcrt and pfkelch13 gene mutations in Plasmodium falciparum parasite population in Uganda
    (Plos one, 2022) Ocan, Moses; Katabazi Ashaba, Fred; Mwesigwa, Savannah; Edgar, Kigozi; Kamya, Moses R.; Nsobya, Sam L.
    In Uganda, Artemether-Lumefantrine and Artesunate are recommended for uncomplicated and severe malaria respectively, but are currently threatened by parasite resistance. Genetic and epigenetic factors play a role in predisposing Plasmodium falciparum parasites to acquiring Pfkelch13 (K13) mutations associated with delayed artemisinin parasite clearance as reported in Southeast Asia. In this study, we report on the prevalence of mutations in the K13, pfmdr-2 (P. falciparum multidrug resistance protein 2), fd (ferredoxin), pfcrt (P. falciparum chloroquine resistance transporter), and arps10 (apicoplast ribosomal protein S10) genes in Plasmodium falciparum parasites prior to (2005) and after (2013) introduction of artemisinin combination therapies for malaria treatment in Uganda. A total of 200 P. falciparum parasite DNA samples were screened. Parasite DNA was extracted using QIAamp DNA mini kit (Qiagen, GmbH, Germany) procedure. The PCR products were sequenced using Sanger dideoxy sequencing method. Of the 200 P. falciparum DNA samples screened, sequencing for mutations in K13, pfmdr-2, fd, pfcrt, arps10 genes was successful in 142, 186, 141, 128 and 74 samples respectively. Overall, we detected six (4.2%, 6/142; 95%CI: 1.4–7.0) K13 single nucleotide polymorphisms (SNPs), of which 3.9% (2/51), 4.4% (4/91) occurred in 2005 and 2013 samples respectively. All four K13 SNPs in 2013 samples were non-synonymous (A578S, E596V, S600C and E643K) while of the two SNPs in 2005 samples, one (Y588N) is non-synonymous and the other (I587I) is synonymous. There was no statistically significant difference in the prevalence of K13 (p = 0.112) SNPs in the samples collected in 2005 and 2013. The overall prevalence of SNPs in pfmdr-2 gene was 39.8% (74/186, 95%CI: 25.1–50.4). Of this, 4.2% (4/95), 76.9% (70/91) occurred in 2005 and 2013 samples respectively. In 2005 samples only one SNP, Y423F (4.2%, 4/95) was found while in 2013, Y423F (38.5%, 35/91) and I492V (38.5%, 35/91) SNPs in the pfmdr-2 gene were found. There was a statistically significant difference in the prevalence of pfmdr-2 SNPs in the samples collected in 2005 and 2013 (p<0.001). The overall prevalence of arps10 mutations was 2.7% (2/72, 95%CI: 0.3–4.2). Two mutations, V127M (4.5%: 1/22) and D128H (4.5%: 1/22) in the arps10 gene were each found in P. falciparum parasite samples collected in 2013. There was no statistically significant difference in the prevalence of arps10 SNPs in the samples collected in 2005 and 2013 (p = 0.238). There were more pfmdr-2 SNPs in P. falciparum parasites collected after introduction of Artemisinin combination therapies in malaria treatment. This is an indicator of the need for continuous surveillance to monitor emergence of molecular markers of artemisinin resistance and its potential drivers in malaria affected regions globally
  • Loading...
    Thumbnail Image
    Item
    Unmapped exome reads implicate a role for Anelloviridae in childhood HIV-1 long-term non-progression
    (NPJ Genomic Medicine, 2021) Mwesigwa, Savannah; Williams, Lesedi; Retshabile, Gaone; Katagirya, Eric; Mboowa, Gerald; Mlotshwa, Busisiwe; Kyobe, Samuel; Kateete, David P.; Mujjwiga Wampande, Eddie; Wayengera, Misaki; Wata Mpoloka, Sununguko; Mirembe, Angella N.; Kasvosve, Ishmael; Morapedi, Koketso; Kisitu, Grace P.; Kekitiinwa, Adeodata R.; Anabwani, Gabriel; Joloba, Moses L.; Matovu, Enock; Mulindwa, Julius; Noyes, Harry; Botha, Gerrit; Brown, Chester W.; Mardon, Graeme; Matshaba, Mogomotsi; Hanchard, Neil A.
    Human immunodeficiency virus (HIV) infection remains a significant public health burden globally. The role of viral co-infection in the rate of progression of HIV infection has been suggested but not empirically tested, particularly among children. We extracted and classified 42 viral species from whole-exome sequencing (WES) data of 813 HIV-infected children in Botswana and Uganda categorised as either long-term non-progressors (LTNPs) or rapid progressors (RPs). The Ugandan participants had a higher viral community diversity index compared to Batswana (p = 4.6 × 10−13), and viral sequences were more frequently detected among LTNPs than RPs (24% vs 16%; p = 0.008; OR, 1.9; 95% CI, 1.6–2.3), with Anelloviridae showing strong association with LTNP status (p = 3 × 10−4; q = 0.004, OR, 3.99; 95% CI, 1.74–10.25). This trend was still evident when stratified by country, sex, and sequencing platform, and after a logistic regression analysis adjusting for age, sex, country, and the sequencing platform (p = 0.02; q = 0.03; OR, 7.3; 95% CI, 1.6–40.5). Torque teno virus (TTV), which made up 95% of the Anelloviridae reads, has been associated with reduced immune activation. We identify an association between viral co-infection and prolonged AIDs-free survival status that may have utility as a biomarker of LTNP and could provide mechanistic insights to HIV progression in children, demonstrating the added value of interrogating off-target WES reads in cohort studies.
  • Loading...
    Thumbnail Image
    Item
    Whole-exome sequencing of sickle cell disease patients with hyperhemolysis syndrome suggests a role for rare variation in disease predisposition
    (Transfusion, 2018) Mwesigwa, Savannah; Moulds, Joann M.; Chen, Alice; Flanagan, Jonathan; Sheehan, Vivien A.; George, Alex; Hanchard, Neil A.
    Hyperhemolysis syndrome (HHS) is an uncommon, but life-threatening, transfusion-related complication of red blood cell transfusion. HHS has predominantly been described in patients with sickle cell disease (SCD) and is difficult to diagnose and treat. The pathogenesis of HHS, including its occurrence in only a subset of apparently susceptible individuals, is poorly understood. We undertook whole-exome sequencing (WES) of 12 SCD-HHS patients to identify shared genetic variants that might be relevant to the development of HHS. STUDY DESIGN AND METHODS—DNA from adults with SCD having at least one previous episode of HHS were subject to WES. High-quality variants were passed through a series of bioinformatics filters to identify variants that were uncommon among African populations represented in public databases. Recurrent, putative loss-of-function variants occurring in biologically plausible genes were prioritized and then genotyped in a larger, ancestry-matched cohort of non-HHS controls. RESULTS—A rare, heterozygous stop-gain variant (p.Glu210Ter) in MBL2 was significantly enriched among HHS cases (p = 0.002). This variant is predicted to result in a premature termination codon that escapes nonsense-mediated mRNA decay, potentially leading to a novel phenotype. We also observed a complex insertion-deletion variant in the final exon of KLRC3 that was enriched among cases (p = 0.0019), although neither variant was found among seven pediatric SCD-HHS patients. CONCLUSION—Our results suggest a potential role for rare genetic defects in the development of HHS among adult SCD patients. Such enriched variants may ultimately be useful for identifying high-risk individuals and informing therapeutic approaches in HHS.
  • Loading...
    Thumbnail Image
    Item
    Whole-Exome Sequencing Reveals Uncaptured Variation and Distinct Ancestry in the Southern African Population of Botswana
    (The American Journal of Human Genetics, 2018) Retshabile, Gaone; Mlotshwa, Busisiwe C.; Williams, Lesedi; Mwesigwa, Savannah; Mboowa, Gerald; Huang, Zhuoyi; Rustagi, Navin; Swaminathan, Shanker; Katagirya, Eric; Kyobe, Samuel; Wayengera, Misaki; Kisitu, Grace P.; Kateete, David P.; Wampande, Eddie M.; Maplanka, Koketso; Kasvosve, Ishmael; Pettitt, Edward D.; Matshaba, Mogomotsi; Nsangi, Betty; Marape, Marape; Tsimako-Johnstone, Masego; Brown, Chester W.; Yu, Fuli; Kekitiinwa, Adeodata; Joloba, Moses; Mpoloka, Sununguko W.; Mardon, Graeme; Anabwani, Gabriel; Hanchard, Neil A.
    Large-scale, population-based genomic studies have provided a context for modern medical genetics. Among such studies, however, African populations have remained relatively underrepresented. The breadth of genetic diversity across the African continent argues for an exploration of local genomic context to facilitate burgeoning disease mapping studies in Africa.We sought to characterize genetic variation and to assess population substructure within a cohort of HIV-positive children from Botswana—a Southern African country that is regionally underrepresented in genomic databases. Using whole-exome sequencing data from 164 Batswana and comparisons with 150 similarly sequenced HIV-positive Ugandan children, we found that 13%–25% of variation observed among Batswana was not captured by public databases. Uncaptured variants were significantly enriched (p ¼ 2.2 3 10 16) for coding variants with minor allele frequencies between 1% and 5% and included predicted-damaging non-synonymous variants. Among variants found in public databases, corresponding allele frequencies varied widely, with Botswana having significantly higher allele frequencies among rare (<1%) pathogenic and damaging variants. Batswana clustered with other Southern African populations, but distinctly from 1000 Genomes African populations, and had limited evidence for admixture with extra-continental ancestries. We also observed a surprising lack of genetic substructure in Botswana, despite multiple tribal ethnicities and language groups, alongside a higher degree of relatedness than purported founder populations from the 1000 Genomes project. Our observations reveal a complex, but distinct, ancestral history and genomic architecture among Batswana and suggest that disease mapping within similar Southern African populations will require a deeper repository of genetic variation and allelic dependencies than presently exists.
  • Loading...
    Thumbnail Image
    Item
    Workshop-based learning and networking: a scalable model for research capacity strengthening in low- and middle-income countries
    (Global Health Action, 2022) Perier, Celine; Nasinghe, Emmanuel; Charles, Isabelle; Ssetaba, Leoson Junior; Ahyong, Vida; Bangs, Derek; Beatty, P. Robert; Czudnochowski, Nadine; Diallo, Amy; Birungi, Joanah; Kalantar, Katrina; Kateete, David; Mwesigwa, Savannah; Joloba, Moses L.; Schaletzky, Julia
    Science education and research have the potential to drive profound change in low- and middle-income countries (LMICs) through encouraging innovation, attracting industry, and creating job opportunities. However, in LMICs, research capacity is often limited, and acquisition of funding and access to state-of-the-art technologies is challenging. The Alliance for Global Health and Science (the Alliance) was founded as a partnership between the University of California, Berkeley (USA) and Makerere University (Uganda), with the goal of strengthening Makerere University’s capacity for bioscience research. The flagship program of the Alliance partnership is the MU/UCB Biosciences Training Program, an in-country, hands-on workshop model that trains a large number of students from Makerere University in infectious disease and molecular biology research. This approach nucleates training of larger and more diverse groups of students, development of mentoring and bi-directional research partnerships, and support of the local economy. Here, we describe the project, its conception, implementation, challenges, and outcomes of bioscience research workshops. We aim to provide a blueprint for workshop implementation, and create a valuable resource for bioscience research capacity strengthening in LMICs.

Research Dissemination Platform copyright © 2002-2025 NRU

  • Cookie settings
  • Privacy policy
  • End User Agreement
  • Send Feedback