The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Gorilla Gut Microbiota

L'objectif principal de ce travail etait d'explorer les bactéries pathogènes que recèle le tube digestif des gorilles. Pour ce faire, un total de 48 échantillons de selles, provenant du Cameroun, appartenant à 21 gorilles ont été analysés. D'abord la culturomique et le pyroséquençage ont été utilisés pour évaluer exhaustivement la diversité bactérienne. En appliquant la culturomique, 86 conditions de culture dont des milieux fabriqués à base de plantes tropicales, sur un échantillon de selles de gorille, 12 800 colonies microbiennes ont été isolées et testées, et 147 espèces bactériennes identifiées. De nombreux pathogènes opportunistes ont été observés, dont 8 qui sont fréquemment associés à des maladies chez l'homme: Mycobacterium bolletii, Proteus mirabilis, Acinetobacter baumannii, Klebsiella pneumoniae, Serratia marcescens, Escherichia coli, Staphylococcus aureus et Clostridium botulinum. En utilisant la PCR en temps réel pour cribler des pathogènes bactériens dans les 48 échantillons de selles de gorilles, des bactéries fastidieuses telles que Bartonella spp. Borrelia spp., Coxiella burnetii, Tropheryma whipplei ont été observées. Nous avons estimé la prévalence de ces agents pathogènes qui varie entre 4,76% et 85,7%. Ce travail a permis de savoir que l'homme et le gorille ont en commun plusieurs espèces bactériennes dont des pathogènes émergents. Par conséquent, les gorilles sauvages peuvent servir de réservoir et de source pour l'émergence et/ou la réémergence des bactéries pathogènes pour l'homme.The main objective of this work is to explore the gorilla's potential role as a reservoir for pathogenic bacteria. We used both microbial culturomics and pyrosequencing to analyze the gorilla gut bacteria. By applying culturomics to one index gorilla, we tested 12,800 colonies and identified 147 different bacterial species, including 5 new species. Many opportunistic human pathogens were observed, including 8 frequently associated with human disease: Mycobacterium bolletii, Proteus mirabilis, Acinetobacter baumannii, Klebsiella pneumoniae, Serratia marcescens, Escherichia coli, Staphylococcus aureus and Clostridium botulinum. Using specific real-time PCR on 48 gorilla fecal samples, we also observed the fastidious pathogens Bartonella spp. Borrelia spp., Coxiella burnetii, Tropheryma whipplei. Using microsatellite analysis of the gorilla samples, we estimated that the prevalence of these pathogens was between 4.76% and 85.7%. Therefore, the gorilla shares many bacterial pathogens with humans, which suggests that wild gorillas might be a reservoir for the emergence and/or reemergence of these pathogens, especially in areas where human and gorilla habitats overlap and because of the increasing presence of humans in the African equatorial forests

Non-contiguous finished genome sequence and description of Bacillus massiliogorillae sp. nov.

International audienc

Non-contiguous finished genome sequence and description of Gorillibacterium massiliense gen. nov, sp. nov., a new member of the family Paenibacillaceae

International audienceStrain G5T gen. nov., sp. nov. is the type strain of Gorillibacterium massiliense, a newly proposed genus within the family Paenibacillaceae. This strain, whose genome is described here, was isolated in France from a stool sample of a wild Gorilla gorilla subsp. gorilla from Cameroon. G. massiliense is a facultatively anaerobic, Gram negative rod. Here we describe the features of this bacterium, together with the complete genome sequence and annotation. The 5,546,433 bp long genome (1 chromosome but no plasmid) contains 5,145 protein-coding and 76 RNA genes, including 69 tRNA genes

Non-contiguous finished genome sequence and description of Paenibacillus gorillae sp. nov.

International audienceStrain G1T sp. nov. is the type strain of Paenibacillus gorillae a newly proposed species within the genus Paenibacillus. This strain, whose genome is described here, was isolated in France from the fecal sample of a wild western lowland gorilla from Cameroon. P. gorillae is a facultative anaerobic, Gram-negative, rod-shaped bacterium. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 6,257,967 bp long genome (one chromosome but no plasmid) contains 5,856 protein-coding and 62 RNAs genes, including 60 tRNA genes

Non contiguous-finished genome sequence and description of Microbacterium gorillae sp. nov.

International audienceStrain G3(T) (CSUR P207 = DSM 26203) was isolated from the fecal sample of a wild gorilla (Gorilla gorilla subsp gorilla) from Cameroon. It is a Gram-positive, facultative anaerobic short rod. This strain exhibits a 16S rRNA sequence similarity of 98.2 % with Microbacterium thalassium, the closest validly published Microbacterium species and member of the family Microbacteriaceae. Moreover, it shows a low MALDI-TOF-MS score (1.1 to 1.3) that does not allow any identification. Thus, it is likely that this strain represents a new species. Here we describe the phenotypic features of this organism, the complete genome sequence and annotation. The 3,692,770 bp long genome (one chromosome but no plasmid) contains 3,505 protein-coding and 61 RNA genes, including 4 rRNA genes. In addition, digital DNA-DNA hybridization values for the genome of the strain G3(T) against the closest Microbacterium genomes range between 19.7 to 20.5, once again confirming its new status as a new species. On the basis of these polyphasic data, consisting of phenotypic and genomic analyses, we propose the creation of Microbacterium gorillae sp. nov. that contains the strain G3(T)

General characteristics of the study population (n = 99 participants).

General characteristics of the study population (n = 99 participants).</p

GISAID accession numbers associated with this study.

GISAID accession numbers associated with this study.</p

Sequences used from GISAID and acknowledgments.

SARS-CoV-2 has claimed several million lives since its emergence in late 2019. The ongoing evolution of the virus has resulted in the periodic emergence of new viral variants with distinct fitness advantages, including enhanced transmission and immune escape. While several SARS-CoV-2 variants of concern trace their origins back to the African continent—including Beta, Eta, and Omicron–most countries in Africa remain under-sampled in global genomic surveillance efforts. In an effort to begin filling these knowledge gaps, we conducted retrospective viral genomic surveillance in Guinea from October 2020 to August 2021. We found that SARS-CoV-2 clades 20A, 20B, and 20C dominated throughout 2020 until the coincident emergence of the Alpha and Eta variants of concern in January 2021. The Alpha variant remained dominant throughout early 2021 until the arrival of the Delta variant in July. Surprisingly, despite the small sample size of our study, we also found the persistence of the early SARS-CoV-2 clade 19B as late as April 2021. Together, these data help fill in our understanding of the SARS-CoV-2 population dynamics in West Africa early in the COVID-19 pandemic.</div

SARS-CoV-2 sequence abundance and lineage distributions among African regions in GISAID.

A) Monthly number of sequences by lineage and B) monthly lineage frequency distribution using Pango nomenclature for lineages in Guinea compared to the lineages with a frequency >1% observed in surrounding African regions. All GISAID sequences deposited up to July 31st were used to examine the similarity in lineage distribution between Guinea and close by African regions. The number of sequences used per geographical location is indicated in panel A).</p