Full length genomic sanger sequencing and phylogenetic analysis of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Nigeria

Mitochondrial DNA D-Loop Polymorphisms among the Galla Goats Reveals Multiple Maternal Origins with Implication on the Functional Diversity of the HSP70 Gene

Despite much attention given to the history of goat evolution in Kenya, information on the origin, demographic history, dispersal route, and genetic diversity of Galla goats remains unclear. Here, we examined the genetic background, diversity, demographic history, and population genetic variation of Galla goats using mtDNA D-loop and HSP70 single-nucleotide polymorphism markers. The results revealed 90 segregating sites and 68 haplotypes in a 600-bp mtDNA D-loop sequence. The overall mean mitochondrial haplotype diversity was 0.993. The haplotype diversities ranged between 0.8939 ± 0.0777 and 1.0000 ± 0.0221 in all populations supporting high genetic diversity. Mitochondrial phylogenetic analysis revealed three Galla goat haplogroups (A, G, and D), supporting multiple maternal ancestries, of which haplogroup A was the most predominant. Analysis of molecular variance (AMOVA) showed considerable variation within populations at 94.39%, evidence of high genetic diversity. Bimodal mismatch distribution patterns were observed while most populations recorded negative results for Tajima and Fu's Fs neutrality tests supporting population expansion. Genetic variation among populations was also confirmed using HSP70 gene fragment sequences, where six polymorphic sites which defined 21 haplotypes were discovered. Analysis of molecular variance revealed a significant FST index value of 0.134 and a high FIS index value of 0.746, an indication of inbreeding. This information will pave the way for conservation strategies and informed breeding to improve Galla or other goat breeds for climate-smart agriculture.

Genomic surveillance of genes encoding the SARS-CoV-2 spike protein to monitor for emerging variants on Jeju Island, Republic of Korea

Introduction

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has been fueled by new variants emerging from circulating strains. Here, we report results from a genomic surveillance study of SARS-CoV-2 on Jeju Island, Republic of Korea, from February 2021 to September 2022.

Methods

A total of 3,585 SARS-CoV-2 positive samples were analyzed by Sanger sequencing of the gene encoding the spike protein before performing phylogenetic analyses.

Results

We found that the Alpha variant (B.1.1.7) was dominant in May 2021 before being replaced by the Delta variant (B.1.617.2) in July 2021, which was dominant until December 2021 before being replaced by the Omicron variant. Mutations in the spike protein, including N440K and G446S, have been proposed to contribute to immune evasion, accelerating the spread of Omicron variants.

Discussion

Our results from Juju Island, Republic of Korea, are consistent with and contribute to global surveillance efforts crucial for identifying new variants of concern of SARS-CoV-2 and for monitoring the transmission dynamics and characteristics of known strains.

SpikeSeq: A rapid, cost efficient and simple method to identify SARS-CoV-2 variants of concern by Sanger sequencing part of the spike protein gene

In 2020, the novel coronavirus, SARS-CoV-2, caused a pandemic, which is still raging at the time of writing this. Here, we present results from SpikeSeq, the first published Sanger sequencing-based method for the detection of Variants of Concern (VOC) and key mutations, using a 1 kb amplicon from the recognized ARTIC Network primers. The proposed setup relies entirely on materials and methods already in use in diagnostic RT-qPCR labs and on existing commercial infrastructure offering sequencing services. For data analysis, we provide an automated, open source, and browser-based mutation calling software (https://github.com/kblin/covid-spike-classification, https://ssi.biolib.com/covid-spike-classification). We validated the setup on 195 SARS-CoV-2 positive samples, and we were able to profile 85% of RT-qPCR positive samples, where the last 15% largely stemmed from samples with low viral count. We compared the SpikeSeq results to WGS results. SpikeSeq has been used as the primary variant identification tool on > 10.000 SARS-CoV-2 positive clinical samples during 2021. At approximately 4€ per sample in material cost, minimal hands-on time, little data handling, and a short turnaround time, the setup is simple enough to be implemented in any SARS-CoV-2 RT-qPCR diagnostic lab. Our protocol provides results that can be used to choose antibodies in a clinical setting and for the tracking and surveillance of all positive samples for new variants and known ones such as Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1) Delta (B.1.617.2), Omicron BA.1(B.1.1.529), BA.2, BA.4/5, BA.2.75.x, and many more, as of October 2022.

SARS-CoV-2 spike gene Sanger sequencing methodology to identify variants of concern

The global demand for rapid identification of circulating SARS-CoV-2 variants of concern has led to a shortage of commercial kits. Therefore, this study aimed to develop and validate a rapid, cost-efficient genome sequencing protocol to identify circulating SARS-CoV-2 (variants of concern). Sets of primers flanking the SARS-CoV-2 spike gene were designed, verified and then validated using 282 nasopharyngeal positive samples for SARS-CoV-2. Protocol specificity was confirmed by comparing these results with SARS-CoV-2 whole-genome sequencing of the same samples. Out of 282 samples, 123 contained the alpha variant, 78 beta and 13 delta, which were indicted using in-house primers and next-generation sequencing; the numbers of variants found were 100% identical to the reference genome. This protocol is easily adaptable for detection of emerging variants during the pandemic.

The application of a novel 5-in-1 multiplex reverse transcriptase-polymerase chain reaction assay for rapid detection of SARS-CoV-2 and differentiation between variants of concern

OBJECTIVES

We have established a novel 5-in-1 VOC assay to rapidly detect SARS-CoV-2 and immediately distinguish whether positive samples represent variants of concern (VOCs).

METHODS

This assay could distinguish among five VOCs: Alpha, Beta, Gamma, Delta, and Omicron, in a single reaction tube. The five variants exhibit different single nucleotide polymorphisms (SNPs) in their viral genome, which can be used to distinguish them. We selected target SNPs in the spike gene, including N501Y, P681R, K417N, and deletion H69/V70 for the assay.

RESULTS

The limit of detection of each gene locus was 80 copies per polymerase chain reaction. We observed a high consistency among the results when comparing the performance of our 5-in-1 VOC assay, whole gene sequencing, and the Roche VirSNiP SARS-CoV-2 test in retrospectively analyzing 150 clinical SARS-CoV-2 variant positive samples. The 5-in-1 VOC assay offers an alternative and rapid high-throughput test for most diagnostic laboratories in a flexible sample-to-result platform.

CONCLUSION

The assay can also be applied in a commercial platform with the completion of the SARS-CoV-2 confirmation test and identification of its variant within 2.5 hours.

People's willingness to use COVID-19 self-testing in Nigeria: a cross-sectional survey

OBJECTIVES

Nigeria has been badly affected by the COVID-19 pandemic, and the poor testing coverage in the country may make controlling the spread of COVID-19 challenging. The aim of this study was to assess the general public's acceptability of SARS-CoV-2 self-testing as an approach which could help to address this gap.

SETTING

A household-based survey was conducted in five urban and five rural local government areas in the states of Akwa Ibom, Anambra, Benue, Kaduna and Lagos, in mid-2021.

PARTICIPANTS

2126 respondents (969 were female) participated. A five-pronged, probabilistic sampling approach was used to recruit individuals older than 17 years and available to participate when randomly approached in their households by the surveyors. A 35-item questionnaire was used to collect data on their values towards SARS-CoV-2 self-testing. Primary outcomes were: likelihood to use a self-test; willingness to pay for a self-test; and likely actions following a reactive self-test result.

RESULTS

Of the total 2126 respondents, 14 (0.66%) were aware of COVID-19 self-testing, 1738 (81.80%) agreed with the idea of people being able to self-test for COVID-19, 1786 (84.05%) were likely/very likely to use self-tests if available, 1931 (90.87%) would report a positive result and 1875 (88.28%) would isolate if they self-tested positive. Factors significantly associated with the use of a self-test were having a college education or higher (adjusted Odds Ratio (AOR): 1.55; 95% CI: 1.03 to 2.33), full-time employment (AOR: 1.67; 95% CI: 1.06 to 2.63), feeling at moderate/high risk of COVID-19 (AOR: 2.43; 95% CI: 1.70 to 3.47) and presence of individuals at risk of COVID-19 within the household (AOR: 1.38; 95% CI: 1.06 to 1.78).

CONCLUSION

A majority of Nigerians agree with the concept of COVID-19 self-testing and would act to protect public health on self-testing positive. Self-test implementation research is necessary to frame how acceptability impacts uptake of preventive behaviours following a positive and a negative self-test result.

A Simplified Sanger Sequencing Method for Detection of Relevant SARS-CoV-2 Variants

Molecular surveillance of the new coronavirus through new genomic sequencing technologies revealed the circulation of important variants of SARS-CoV-2. Sanger sequencing has been useful in identifying important variants of SARS-CoV-2 without the need for whole-genome sequencing. A sequencing protocol was constructed to cover a region of 1000 base pairs, from a 1120 bp product generated after a two-step RT-PCR assay in samples positive for SARS-CoV-2. Consensus sequence construction and mutation identification were performed. Of all 103 samples sequenced, 69 contained relevant variants represented by 20 BA.1, 13 delta, 22 gamma, and 14 zeta, identified between June 2020 and February 2022. All sequences found were aligned with representative sequences of the variants. Using the Sanger sequencing methodology, we were able to develop a more accessible protocol to assist viral surveillance with a more accessible platform.

Receptor-Binding-Motif-Targeted Sanger Sequencing: a Quick and Cost-Effective Strategy for Molecular Surveillance of SARS-CoV-2 Variants

Whole-genome sequencing (WGS) is the gold standard for characterizing the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome and identification of new variants. However, the cost involved and time needed for WGS prevent routine, rapid clinical use. This study aimed to develop a quick and cost-effective surveillance strategy for SARS-CoV-2 variants in saliva and nasal swab samples by spike protein receptor-binding-motif (RBM)-targeted Sanger sequencing. Saliva and nasal swabs prescreened for the presence of the nucleocapsid (N) gene of SARS-CoV-2 were subjected to RBM-specific single-amplicon generation and Sanger sequencing. Sequences were aligned by CLC Sequence Viewer 8, and variants were identified based upon specific mutation signature. Based on this strategy, the present study identified Alpha, Beta/Gamma, Delta, and Omicron variants in a quick and cost-effective manner.

IMPORTANCE The coronavirus disease 2019 (COVID-19) pandemic resulted in 427 million infections and 5.9 million deaths globally as of 21 February 2022. SARS-CoV-2, the causative agent of the COVID-19 pandemic, frequently mutates and has developed into variants of major public health concerns. Following the Alpha variant (B.1.1.7) infection wave, the Delta variant (B.1.617.2) became prevalent, and now the recently identified Omicron (B.1.1.529) variant is spreading rapidly and forming BA.1, BA.1.1, BA.2, BA.3, BA.4, and BA.5 lineages of concern. Prompt identification of mutational changes in SARS-CoV-2 variants is challenging but critical to managing the disease spread and vaccine/therapeutic modifications. Considering the cost involved and resource limitation of WGS globally, an RBM-targeted Sanger sequencing strategy is adopted in this study for quick molecular surveillance of SARS-CoV-2 variants.

Phylogenetic and genome-wide mutational analysis of SARS-CoV-2 strains circulating in Nigeria: no implications for attenuated COVID-19 outcomes

OBJECTIVES

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19). The COVID-19 incidence and mortality rates are low in Nigeria compared to global trends. This research mapped the evolution of SARS-CoV-2 circulating in Nigeria and globally to determine whether the Nigerian isolates are genetically distinct from strains circulating in regions of the world with a high disease burden.

METHODS

Bayesian phylogenetics using BEAST 2.0, genetic similarity analyses, and genomewide mutational analyses were used to characterize the strains of SARS-CoV-2 isolated in Nigeria.

RESULTS

SARS-CoV-2 strains isolated in Nigeria showed multiple lineages and possible introductions from Europe and Asia. Phylogenetic clustering and sequence similarity analyses demonstrated that Nigerian isolates were not genetically distinct from strains isolated in other parts of the globe. Mutational analysis demonstrated that the D614G mutation in the spike protein, the P323L mutation in open reading frame 1b (and more specifically in NSP12), and the R203K/ G204R mutation pair in the nucleocapsid protein were most prevalent in the Nigerian isolates.

CONCLUSION

The SARS-CoV-2 strains in Nigeria were neither phylogenetically nor genetically distinct from virus strains circulating in other countries of the world. Thus, differences in SARS-CoV-2 genomes are not a plausible explanation for the attenuated COVID-19 outcomes in Nigeria.

SARS-CoV-2 variant detection with ADSSpike

The SARS-CoV-2 coronavirus pandemic has been an unprecedented challenge to global pandemic response and preparedness. With the continuous appearance of new SARS-CoV-2 variants, it is imperative to implement tools for genomic surveillance and diagnosis in order to decrease viral transmission and prevalence. The ADSSpike workflow was developed with the goal of identifying signature SNPs from the S gene associated with SARS-CoV-2 variants through amplicon deep sequencing. Seventy-two samples were sequenced, and 30 mutations were identified. Among those, signature SNPs were linked to 2 Zeta-VOI (P.2) samples and one to the Alpha-VOC (B.1.17). An average depth of 700 reads was found to properlycorrectly identify all SNPs and deletions pertinent to SARS-CoV-2 mutants. ADSSpike is the first workflow to provide a practical, cost-effective, and scalable solution to diagnose SARS-CoV-2 VOC/VOI in the clinical laboratory, adding a valuable tool to public health measures to fight the COVID-19 pandemic for approximately $41.85 USD/reaction.

Consolidating and Upscaling Molecular Research Capacity in Nigeria: On Who's Account?

Molecular research and researchers engage in studies that seek to understand the structures, functions, and interactions of biomolecules as the basis for cellular and systemic effects in living organisms. This research approach was made possible by considerable technological advancements that equip researchers with tools to view biomolecules. Although molecular research holds great promises for improving lives and living, the technological requirements and equipment to undertake molecular research are quite expensive, often requiring a heavy start-up capital or investment. In developing countries such as Nigeria, where the majority of the population lives below the poverty line and research funding is abysmally low, such heavy investments into research that do not provide immediate solutions to societal problems are difficult. This is mostly due to limited resources available to tackle many urgent and pressing needs, and limited perspective and understanding of policymakers, leading to infrastructural and skilled personnel deficit to support molecular research. Despite all these, the field of molecular research continues to grow exponentially globally, hence, funding and investments into this critical life science research area have become imperative. With the rich biodiversity of humans, animals, and plants in Nigeria, and the huge burden of infectious diseases in the country or region, global advances in genomics and proteomics studies will be incomplete without adequate contribution from Nigeria and sub-Saharan Africa region. This paper examines the progression and challenges of undertaking molecular research in Nigeria, and how Nigerian molecular research scientists are tackling these issues, with recommendations for improved molecular research capacity and output in the country or region.

Evaluation of respiratory tract bacterial co-infections in SARS-CoV-2 patients with mild or asymptomatic infection in Lagos, Nigeria

BACKGROUND

A common complication of any respiratory disease by a virus could be a secondary bacterial infection, which is known to cause an increase in severity. It is, however, not clear whether the presence of some opportunistic pathogens called pathobionts contributes to the severity of the disease. In COVID-19 patients, undetected bacterial co-infections may be associated with the severity of the disease. Therefore, we investigated the implications of bacterial co-infections in COVID-19 cases.

RESULTS

This is a cross-sectional study that involved archived specimens collected from nasopharyngeal samples of 150 people for COVID-19 screening in Lagos. DNA extraction from the samples was carried out to determine the presence of five respiratory bacterial pathogens using nested real-time PCR, and data were analysed using the Chi-square test. Of the 150 samples collected, 121 (80.7%) were positive for SARs-CoV-2 infection and 29 were negative. The proportion of patients with bacteria co-infection in COVID-19-negative, asymptomatic, and mild cases were 93.1%, 70.7%, and 67.5%, respectively. There was no statistically significant difference between mild COVID-19 conditions and bacteria co-infection (p = 0.097). There was also no significant difference in the nasal carriage of Staphylococcus aureus, Mycoplasma pneumoniae, and Haemophilus spp. However, there was a statistically significant increase in the carriage of Moraxella catarrhalis and Chlamydophila pneumoniae among COVID-19-negative patients when compared with the positive patients (p value = 0.003 and 0.000 for Moraxella catarrhalis and Chlamydophila pneumoniae, respectively).

CONCLUSIONS

The current study shows that bacterial co-infection and superinfection with COVID-19 are not associated with mild and asymptomatic COVID-19 cases in our setting. However, given the high prevalence of Staphylococcus aureus and Mycoplasma pneumoniae among the mild COVID-19 cases seen in this study, early diagnosis and treatment of these bacterial co-infections are still encouraged to mitigate the effect on the severity of COVID-19.

Nucleic Acid Testing of SARS-CoV-2

The coronavirus disease 2019 (COVID-19) has caused a large global outbreak. It is accordingly important to develop accurate and rapid diagnostic methods. The polymerase chain reaction (PCR)-based method including reverse transcription-polymerase chain reaction (RT-PCR) is the most widely used assay for the detection of SARS-CoV-2 RNA. Along with the RT-PCR method, digital PCR has emerged as a powerful tool to quantify nucleic acid of the virus with high accuracy and sensitivity. Non-PCR based techniques such as reverse transcription loop-mediated isothermal amplification (RT-LAMP) and reverse transcription recombinase polymerase amplification (RT-RPA) are considered to be rapid and simple nucleic acid detection methods and were reviewed in this paper. Non-conventional molecular diagnostic methods including next-generation sequencing (NGS), CRISPR-based assays and nanotechnology are improving the accuracy and sensitivity of COVID-19 diagnosis. In this review, we also focus on standardization of SARS-CoV-2 nucleic acid testing and the activity of the National Metrology Institutes (NMIs) and highlight resources such as reference materials (RM) that provide the values of specified properties. Finally, we summarize the useful resources for convenient COVID-19 molecular diagnostics.