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INTRODUCTION: Cancer research is critical for cancer control policies; however, the state of cancer research activities in Botswana is largely unknown. The goal of this review was to describe trends and patterns of cancer research outputs in Botswana. METHODS: PubMed, Web of Science, EBSCOhost, African Journals Online, and African Index Medicus databases were systematically searched for peer-reviewed, primary cancer-related research articles published on the Botswana population or by Botswana institutions between January 2009 and June 2021. RESULTS: Of the 86 publications included, 39 (45 %) were about cervical cancer, followed by breast cancer (10 %) and Kaposi sarcoma (7 %). The remainder (27 %) were not focused on any specific cancer type. The research activities were skewed towards three main areas of scientific interest: early detection, diagnosis, and prognosis; cancer control, survivorship, and outcomes; and treatment. Botswana was represented by authors in the first (54 %), last (53 %), and any authorship (53 %) positions. The United States of America had the strongest collaborative partnerships with Botswana, followed by the United Kingdom and South Africa. The majority of funding institutions were American (76 %) and the National Institutes of Health was the most mentioned funding organization, accounting for 33 % of all financial acknowledgments. Only 9 % of the funding acknowledgments came from Botswana. CONCLUSION AND POLICY SUMMARY: Although cancer research in Botswana is expanding because of substantial foreign assistance, it is also hampered by a lack of local funding, minimal participation by Botswana-affiliated researchers, and research that is not aligned with disease burden. Our study highlights the need to strengthen local research capacity in Botswana.

Background We aimed to determine the prevalence of hepatitis B virus (HBV) infection among people with human immunodeficiency virus (PWH) in rural and periurban communities in Botswana. Methods PWH from a previous population-based study, the Botswana Prevention Combination Project, which enrolled adults in 30 communities across Botswana (2013–2018), were screened for HBV surface antigen (HBsAg) and HBV core antibody (anti-HBc). HBsAg-positive (HBsAg+) samples were further screened for HBV core immunoglobulin M antibodies (anti-HBc immunoglobulin M [IgM]) and HBV e antigen (HBeAg). We quantified HBV viral load on participants who tested positive (n = 148) and negative for HBsAg (n = 381). Results Of 3304 participants tested, 271 (8% [95% confidence interval {CI}, 7%–9%]) were HBsAg+ while 1788 (56% [95% CI, 54%–57%]) of 3218 PWH whom we tested had positive anti-HBc. Approximately 88% of HBsAg+ participants were on antiretroviral therapy (ART), 40% and 56% of whom were receiving lamivudine- and tenofovir-containing ART, respectively. Male sex (relative risk ratio [RRR], 1.8 [95% CI, 1.2–2.7]) and the northern geographic region (RRR, 2.5 [95% CI, 1.4–4.7]) were independent predictors of HBV infection (HBsAg+). Of 381 persons with negative HBsAg who were tested for occult HBV, 126 (33% [95% CI, 29%–38%]) had positive HBV DNA. Eleven participants were highly viremic with high HBV viral load while on a lamivudine- or tenofovir-containing regimen. Ten (91%) of these participants also had positive HBeAg serology, while 4 (36%) had positive anti-HBc IgM serology. Conclusions The prevalence of HBV was high among PWH in Botswana while on ART regimens with activity against HBV.

Ontlametse T Bareng,1,2 Wonderful T Choga,1,2 Segomotso T Maphorisa,3 Sekgabo Seselamarumo,1 Kaelo K Seatla,1 Patrick T Mokgethi,1,4 Dorcas Maruapula,1,4 Mompati L Mogwele,1 Doreen Ditshwanelo,1,5 Natasha O Moraka,1 Irene Gobe,2 Modisa S Motswaledi,2 Joseph M Makhema,1,6 Rosemary Musonda,1 Roger Shapiro,1,6 Max Essex,1,6 Vlad Novitsky,1 Sikhulile Moyo,1,2,6 Simani Gaseitsiwe1,6 1Botswana Harvard AIDS Institute Partnership, Gaborone, Botswana; 2School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana; 3Ministry of Health and Wellness, Republic of Botswana, Gaborone, Botswana; 4Department of Biological Sciences, Faculty of Science, University of Botswana, Gaborone, Botswana; 5Department of Biological Science and Biotechnology, Botswana International University of Science and Technology, Palapye, Botswana; 6Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USACorrespondence: Simani Gaseitsiwe, Botswana Harvard AIDS Institute Partnership, Private Bag BO320, Bontleng, Gaborone, Botswana, Tel +267 390 2671, Fax +267 390 1284, Email sgaseitsiwe@bhp.org.bwPurpose: Monitoring HIV-1 drug resistance mutations (DRM) in treated patients on combination antiretroviral therapy (cART) with a detectable HIV-1 viral load (VL) is important for the selection of appropriate cART. Currently, there is limited data on HIV DRM at low-level viremia (LLV) (VL 401– 999 copies/mL) due to the use of a threshold of VL ≥ 1000 copies/mL for HIV DRM testing. We here assess the performance of an in-house HIV drug resistance genotyping assay using plasma for the detection of DRM at LLV.Methods: We used a total of 96 HIV plasma samples from the population-based Botswana Combination Prevention Project (BCPP). The samples were stratified by VL groups: 50 samples had LLV, defined as 401– 999 copies/mL, and 46 had ≥ 1000 copies/mL. HIV pol (PR and RT) region was amplified and sequenced using an in-house genotyping assay with BigDye sequencing chemistry. Known HIV DRMs were identified using the Stanford HIV Drug Resistance Database. Genotyping success rate between the two groups was estimated and compared using the comparison of proportions test.Results: The overall genotyping success rate was 79% (76/96). For VL groups, the genotyping success was 72% (36/50) at LLV and 87% (40/46) at VL ≥ 1000 copies/mL. Among generated sequences, the overall prevalence of individuals with at least 1 major or intermediate-associated DRM was 24% (18/76). The proportions of NNRTI-, NRTI- and PI-associated resistance mutations were 28%, 24%, and 0%, respectively. The most predominant mutations detected were K103N (18%) and M184V (12%) in NNRTI- and NRTI-associated mutations, respectively. The prevalence of DRM was 17% (6/36) at LLV and 30% (12/40) at VL ≥ 1000 copies/mL.Conclusion: The in-house HIV genotyping assay successfully genotyped 72% of LLV samples and was able to detect 17% of DRM amongst them. Our results highlight the possibility and clinical significance of genotyping HIV among individuals with LLV.Keywords: in-house genotyping, low-level viremia, samples, HIV-1C drug resistance testing

Chemical investigation of the root wood of

Chemical investigation of the root wood of Erythrina livingstoniana led to the isolation of one previously undescribed isoflavan (3S,3″R)-7-hydroxy-2′-methoxy-[3″-hydroxy-2″,2″-dimethylpyrano (3′,4′)] isoflavan 1, together with eleven known compounds 2-12. The structure of compound 1 was elucidated on the basis of extensive spectroscopic and spectrometric analyses (1 D and 2 D-NMR and APCI-HRMS), with absolute configurations established by comparison of experimental and DFT calculated ECD data. The assignment of the absolute configurations of C-3 and C-3″ of compounds 2 and 3, respectively, were reported for the first time. Compounds 1 − 4 were evaluated for their antibacterial activities in vitro against E. coli ATCC 25922 and S. aureus ATCC 25923. Compound 1 exhibited moderate antibacterial activity with MIC value of 0.063 mg/mL against the clinically relevant risk-group 2 (RG-2) bacterium S. aureus.

BackgroundCOVID-19 found the world in a state of unpreparedness. While research efforts to develop a vaccine are on-going, others have suggested the use of available vaccines to boost innate immunity.ObjectiveWe analysed three databases: UNICEF Immunization Coverage, Worldometer Corona Virus Updates and World Bank List of Economies to establish the association, if any, between vaccination for various diseases and COVID-19 death rates and recoveries across world economies.ResultsMean percentage death rates were lower in countries that vaccinated for Hepatitis-B birth dose (2.53% vs 3.79%, p = 0.001), Bacille Calmette-Guérin Vaccine (2.93% vs 5.10%, p = 0.025) and Inactivated Polio Vaccine 1st dose (2.8% vs 4.01%, p = 0.022) than those which did not report vaccination. In high income countries, a significant negative correlation with death rates was observed with vaccination for Measles-containing vaccine 2nd dose (r = –0.290, p = 0.032), Rubella-containing vaccine 1st dose (r = –0.325, p = 0.015), Hepatitis B 3rd dose (r = –0.562, p = 3.3 x10−5), Inactivated Polio vaccine 1st dose (r = –0.720, p = 0.008). Inactivated Polio Vaccine 1st dose and Measles-containing vaccine 2nd dose also correlated with better recoveries. In Low Income countries, only Rubella-containing vaccine correlated with lower deaths while Yellow fever vaccine was associated with poorer recoveries.ConclusionOur analysis corroborates the potential benefit of vaccination and warrant further research to explore the rationale for repurposing other vaccines to fight COVID-19.

The causative agent of TB, Mycobacterium tuberculosis (Mtb) is once again the world’s number one infectious killer. M. tuberculosis resides primarily within macrophages and metabolic reprogramming within this intracellular niche is a crucial determinant of virulence. We previously applied the metabolic modelling-based tool 13C-flux spectral analysis (13C-FSA) to show that intracellular M. tuberculosis co-metabolises multiple gluconeogenic and glycolytic carbon substrates by utilizing the reactions of the phosphoenolpyruvate (PEP)-pyruvate-oxaloacetate (OAA) or anaplerotic (ANA) node. However, predicting the metabolic mode of operation required for intracellular survival is chellenging using a metabolic network as the ANA node consists of several apparently functionally redundant bidirectional reactions. Here we use multiple techniques including 13C isotopomer profiling, lipid analysis and fluorescent reporter strains to dissect the role of the ANA node. We show that this node has unexpected roles in the life cycle of M. tuberculosis including lipid biosynthesis, protection from known toxic intracellular carbon sources and redox regulation. Inhibiting enzymes at this node with novel therapeutic compounds restricts the growth of M. tuberculosis and limits the ability of this formidable pathogen to survive within the human host cell identifying the ANA node as a potential druggable pathway for controlling TB.

High-throughput essentiality screens have enabled genome-wide assessments of the genetic requirements for growth and survival of a variety of bacteria in different experimental models. The reliance in many of these studies on transposon (Tn)-based gene inactivation has, however, limited the ability to probe essential gene function or design targeted screens. We interrogated the potential of targeted, large-scale, pooled CRISPR interference (CRISPRi)-based screens to extend conventional Tn approaches in mycobacteria through the capacity for positionally regulable gene repression. Here, we report the utility of the “CRISPRi-Seq” method for targeted, pooled essentiality screening, confirming strong overlap with Tn-Seq datasets. In addition, we exploit this high-throughput approach to provide insight into CRISPRi functionality. By interrogating polar effects and combining image-based phenotyping with CRISPRi-mediated depletion of selected essential genes, we demonstrate that CRISPRi-Seq can functionally validate Transcriptional Units within operons. Together, these observations suggest the utility of CRISPRi-Seq to provide insights into (myco)bacterial gene regulation and expression on a genome-wide scale.

Enzymes at the phosphoenolpyruvate (PEP)–pyruvate–oxaloacetate or anaplerotic (ANA) node control the metabolic flux to glycolysis, gluconeogenesis, and anaplerosis. Here we used genetic, biochemical, and 13C isotopomer analysis to characterize the role of the enzymes at the ANA node in intracellular survival of the world's most successful bacterial pathogen, Mycobacterium tuberculosis (Mtb). We show that each of the four ANA enzymes, pyruvate carboxylase (PCA), PEP carboxykinase (PCK), malic enzyme (MEZ), and pyruvate phosphate dikinase (PPDK), performs a unique and essential metabolic function during the intracellular survival of Mtb. We show that in addition to PCK, intracellular Mtb requires PPDK as an alternative gateway into gluconeogenesis. Propionate and cholesterol detoxification was also identified as an essential function of PPDK revealing an unexpected role for the ANA node in the metabolism of these physiologically important intracellular substrates and highlighting this enzyme as a tuberculosis (TB)-specific drug target. We show that anaplerotic fixation of CO2 through the ANA node is essential for intracellular survival of Mtb and that Mtb possesses three enzymes (PCA, PCK, and MEZ) capable of fulfilling this function. In addition to providing a back-up role in anaplerosis we show that MEZ also has a role in lipid biosynthesis. MEZ knockout strains have an altered cell wall and were deficient in the initial entry into macrophages. This work reveals that the ANA node is a focal point for controlling the intracellular replication of Mtb, which goes beyond canonical gluconeogenesis and represents a promising target for designing novel anti-TB drugs.