Frequency and patterns of second-line resistance conferring mutations among MDR-TB isolates resistant to a second-line drug from eSwatini, Somalia and Uganda (2014-2016).

BACKGROUND: Pulmonary tuberculosis is a leading cause of morbidity and mortality in developing countries. Drug resistance, a huge problem in this contagious disease, is driven by point mutations in the Mycobacterium tuberculosis genome however, their frequencies vary geographically and this affects applicability of molecular diagnostics for rapid detection of resistance. Here, we report the frequency and patterns of mutations associated with resistance to second-line anti-TB drugs in multidrug-resistant (MDR) M. tuberculosis isolates from eSwatini, Somalia and Uganda that were resistant to a second-line anti-TB drug. METHODS: The quinolone resistance determining region (QRDR) of gyrA/gyrB genes and the drug resistance associated fragment of rrs gene from 80 isolates were sequenced and investigated for presence of drug resistance mutations. Of the 80 isolates, 40 were MDR, of which 28 (70%) were resistant to a second-line anti-TB injectable drug, 18 (45%) were levofloxacin resistant while 12 (30%) were extensively drug resistant (XDR). The remaining 40 isolates were susceptible to anti-TB drugs. MIRU-VNTR analysis was performed for M/XDR isolates. RESULTS: We successfully sub-cultured 38 of the 40 M/XDR isolates. The gyrA resistance mutations (Gly88Ala/Cys/Ala, Ala90Val, Ser91Pro, Asp94Gly/Asn) and gyrB resistance mutations (Asp500His, Asn538Asp) were detected in 72.2% (13/18) and 22.2% (4/18) of the MDR and levofloxacin resistant isolates, respectively. Overall, drug resistance mutations in gyrA/gyrB QRDRs occurred in 77.8% (14/18) of the MDR and levofloxacin resistant isolates. Furthermore, drug resistance mutations a1401g and g1484 t in rrs occurred in 64.3% (18/28) of the MDR isolates resistant to a second-line anti-TB injectable drug. Drug resistance mutations were not detected in drug susceptible isolates. CONCLUSIONS: The frequency of resistance mutations to second-line anti-TB drugs in MDR-TB isolates resistant to second line anti-TB drugs from eSwatini, Somalia and Uganda is high, implying that rapid molecular tests are useful in detecting second-line anti-TB drug resistance in those countries. Relatedly, the frequency of fluoroquinolone resistance mutations in gyrB/QRDR is high relative to global estimates, and they occurred independently of gyrA/QRDR mutations implying that their absence in panels of molecular tests for detecting fluoroquinolone resistance may yield false negative results in our setting.

A blended genome and exome sequencing method captures genetic variation in an unbiased, high-quality, and cost-effective manner.

We deployed the Blended Genome Exome (BGE), a DNA library blending approach that generates low pass whole genome (1-4× mean depth) and deep whole exome (30-40× mean depth) data in a single sequencing run. This technology is cost-effective, empowers most genomic discoveries possible with deep whole genome sequencing, and provides an unbiased method to capture the diversity of common SNP variation across the globe. To evaluate this new technology at scale, we applied BGE to sequence >53,000 samples from the Populations Underrepresented in Mental Illness Associations Studies (PUMAS) Project, which included participants across African, African American, and Latin American populations. We evaluated the accuracy of BGE imputed genotypes against raw genotype calls from the Illumina Global Screening Array. All PUMAS cohorts had R 2 concordance ≥95% among SNPs with MAF≥1%, and never fell below ≥90% R 2 for SNPs with MAF<1%. Furthermore, concordance rates among local ancestries within two recently admixed cohorts were consistent among SNPs with MAF≥1%, with only minor deviations in SNPs with MAF<1%. We also benchmarked the discovery capacity of BGE to access protein-coding copy number variants (CNVs) against deep whole genome data, finding that deletions and duplications spanning at least 3 exons had a positive predicted value of ~90%. Our results demonstrate BGE scalability and efficacy in capturing SNPs, indels, and CNVs in the human genome at 28% of the cost of deep whole-genome sequencing. BGE is poised to enhance access to genomic testing and empower genomic discoveries, particularly in underrepresented populations.

Building blocks for better biorepositories in Africa.

BACKGROUND: Biorepositories archive and distribute well-characterized biospecimens for research to support the development of medical diagnostics and therapeutics. Knowledge of biobanking and associated practices is incomplete in low- and middle-income countries where disease burden is disproportionately high. In 2011, the African Society of Human Genetics (AfSHG), the National Institutes of Health (NIH), and the Wellcome Trust founded the Human Heredity and Health in Africa (H3Africa) consortium to promote genomic research in Africa and established a network of three biorepositories regionally located in East, West, and Southern Africa to support biomedical research. This manuscript describes the processes established by H3Africa biorepositories to prepare research sites to collect high-quality biospecimens for deposit at H3Africa biorepositories. METHODS: The biorepositories harmonized practices between the biorepositories and the research sites. The biorepositories developed guidelines to establish best practices and define biospecimen requirements; standard operating procedures (SOPs) for common processes such as biospecimen collection, processing, storage, transportation, and documentation as references; requirements for minimal associated datasets and formats; and a template material transfer agreements (MTA) to govern biospecimen exchange. The biorepositories also trained and mentored collection sites in relevant biobanking processes and procedures and verified biospecimen deposit processes. Throughout these procedures, the biorepositories followed ethical and legal requirements. RESULTS: The 20 research projects deposited 107,982 biospecimens (76% DNA, 81,067), in accordance with the ethical and legal requirements and established best practices. The biorepositories developed and customized resources and human capacity building to support the projects. [The biorepositories developed 34 guidelines, SOPs, and documents; trained 176 clinicians and scientists in over 30 topics; sensitized ethical bodies; established MTAs and reviewed consent forms for all projects; attained import permits; and evaluated pilot exercises and provided feedback. CONCLUSIONS: Biobanking in low- and middle-income countries by local skilled staff is critical to advance biobanking and genomic research and requires human capacity and resources for global partnerships. Biorepositories can help build human capacity and resources to support biobanking by partnering with researchers. Partnerships can be structured and customized to incorporate document development, ethics, training, mentorship, and pilots to prepare sites to collect, process, store, and transport biospecimens of high quality for future research.

Biobanking: Strengthening Uganda's Rapid Response to COVID-19 and Other Epidemics.

Introduction: SARS-CoV-2 is a fatal disease of global public health concern. Measures to reduce its spread critically depend on timely and accurate diagnosis of virus-infected individuals. Biobanks can have a pivotal role in elucidating disease etiology, translation, and advancing public health. In this article, we show how a biobank has been a critical resource in the rapid response to coronavirus disease of 2019 (COVID-19) in Uganda. Materials and Methods: The Integrated Biorepository of H3Africa Uganda established a COVID-19 biobank. Standard Operating Procedures for sample and data collection, sample processing, and storage were developed. An e-questionnaire data tool was used to collect sociodemographic factors. Samples were collected at 7-day intervals from patients, analyzed for key parameters, processed, annotated, characterized, and stored at appropriate temperatures. Results: Stored samples have been used in validation of 17 diagnostic kits, the Cepheid Xpert Xpress SARS-CoV-2 assay, as well as a sample pooling technique for mass screening and polymerase chain reaction assay validation. Kits that passed validation were deployed for mass screening boosting early detection, isolation, and treatment of COVID-19 cases. Also, 10 applications from researchers and biotech companies have been received and approved and 4 grants have been awarded Conclusion: The CoV-Bank has proven to be an invaluable resource in the fight against the COVID-19 pandemic in Uganda, as samples have been resources in the validation and development of COVID-19 diagnostic tools, which are important in tracing and isolation of infected cases to confront, delay, and stop the spread of the SARS-CoV-2 virus.

Whole-genome sequencing of SARS-CoV-2 in Uganda: implementation of the low-cost ARTIC protocol in resource-limited settings.

Background: In January 2020, a previously unknown coronavirus strain was identified as the cause of a severe acute respiratory syndrome (SARS-CoV-2). The first viral whole-genome was sequenced using high-throughput sequencing from a sample collected in Wuhan, China. Whole-genome sequencing (WGS) is imperative in investigating disease outbreak transmission dynamics and guiding decision-making in public health. Methods: We retrieved archived SARS-CoV-2 samples at the Integrated Biorepository of H3Africa Uganda, Makerere University (IBRH3AU). These samples were collected previously from individuals diagnosed with coronavirus disease 2019 (COVID-19) using real-time reverse transcription quantitative polymerase chain reaction (RT-qPCR). 30 samples with cycle thresholds (Cts) values <25 were selected for WGS using SARS-CoV-2 ARTIC protocol at Makerere University Molecular Diagnostics Laboratory. Results: 28 out of 30 (93.3%) samples generated analyzable genomic sequence reads. We detected SARS-CoV-2 and lineages A (22/28) and B (6/28) from the samples. We further show phylogenetic relatedness of these isolates alongside other 328 Uganda (lineage A = 222, lineage B = 106) SARS-CoV-2 genomes available in GISAID by April 22, 2021 and submitted by the Uganda Virus Research Institute. Conclusions: Our study demonstrated adoption and optimization of the low-cost ARTIC SARS-CoV-2 WGS protocol in a resource limited laboratory setting. This work has set a foundation to enable rapid expansion of SARS-CoV-2 WGS in Uganda as part of the Presidential Scientific Initiative on Epidemics (PRESIDE) CoV-bank project and IBRH3AU.