Studies indicate geographical and evolutionary dispersal of beta-coronavirus from African bats

Nigerian research group finds evidence of long-distance transmission and dispersal between bats Coronavirus Separated in Africa, Europe and Asia, as described in a new paper available on Preprint Server. bioRxiv*..

The pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become the decisive global public health crisis of our time. This virus belongs to an extensive group of coronaviruses and is known to have the potential for zoonotic transmission from animals to humans.

Novel Coronavirus SARS-CoV-2 This Scanning Electron Microscopy image reveals SARS-CoV-2 (yellow) (2019-nCoV, a virus that causes COVID-19) from the surface, isolated from a US patient. Thing. Cells cultured in the laboratory (pink). Colorized image captured at NIAID’s Rocky Mountain Laboratories (RML) in Hamilton, MT. Credit: NIAID

Africa’s rich fauna and biodiversity have created new viral disease hotspots. Additional opportunities for the virus are various bats that act as reservoirs and can spread pathogens efficiently (for example, the African fruit bat is known to cover thousands of miles during its migration cycle). ).

Evidence points to African bats as a potential reservoir for several beta coronaviruses that can trigger serious developmental events. Some studies also suggest that SARS-CoV-2 is likely to be spilled into the human population by a zoonotic event involving a SARS-associated beta coronavirus.

Therefore, Abe Northern Federal Medical Center, Covenant University of Otta, And that Ibadan University in Nigeria It was decided to evaluate the phylogenetic diversity and evolutionary dynamics among African beta-coronavirus bats, and their possible dispersal across the continent.

Evolution tree analysis

Three datasets were generated from the viral pathogen resource database for this study. More specifically, the authors obtained sequences for the partial RNA-dependent RNA polymerase (RdRP) gene of the bat coronavirus from seven African countries, four European countries, and three Asian countries.

Information such as host species, country of origin and date of collection was combined with the sequence data for accurate phylogeny. Cluster analysis was performed using specific software to identify sequence similarities and reduce data duplication.

Phylogenetic trees were inferred using MEGA software for manual and automated sequence alignments, and distribution analysis (both geographical and evolutionary) was implemented by BEAST, a Bayesian phylogenetic molecular sequence analysis platform, Markov. An interactive platform made using Chained Monte Carlo and visualized in SpreaD3.

Virus that jumps over the continent

The most common bat species sampled in this study is the Peters dwarf epaulette fruit bat (Micropteropus pusillus). At the same time, Cameroon was the country with the highest distribution of bat species sampled in this study. However, recognized data gaps must be taken into account when assessing the findings.

Peters Dwarf Fruit Bat (Micropteropus pusillus). Image credit: Dave Montreuil / Shutterstock

“This result does not necessarily represent the true picture of bat species diversity in Africa, due to the lack of bat sequence information due to lack of oversight in some countries,” he warned. The study authors state.

In fact, to date, very little research has been done on bat coronaviruses in Africa, and epidemiological information on African beta-bat coronaviruses is quite sparse.

This study adds additional knowledge about beta-coronavirus sequence strains. This revealed that the majority of African strains are contained in strain D-consisting of strains from Cameroon, the Democratic Republic of the Congo, Kenya, Madagascar and Nigeria. This supports previous reports identifying a single clade circulating in the entire continent.

In addition, the researchers suggested an interspecific transmission between strain D beta coronavirus, allowing potential recombination and rapid evolution of this strain. Also, two distinct strains B and C cycling among African bat species were shown.

Finally, the phylogeographic distribution of bat coronaviruses revealed frequent intercontinental and intracontinental diffusion events. The former shows virus spread from China and Hong Kong to Central and Southern Africa, the latter shows direct spread between Cameroon, the Democratic Republic of the Congo, South Africa and from Cameroon to Madagascar.

Research flaws and conclusions

While these insights are crucial for further tracking of coronaviruses, one major study limitation was the inability to analyze spiked protein sequence data for these viruses. Such an approach would have provided better data on infections and their evolution in infectivity.

Furthermore, the demographics reported in this study do not realistically represent the viral population due to the limited size of the datasets used, and represent the true demographics of the African bat coronavirus. It may not be.

“But we have shown the importance of molecular surveillance of potentially zoonotic viruses such as coronavirus,” the study authors say. “We propose a larger transcontinental study involving the entire beta-coronavirus genome sequence to better understand the factors behind their emergence and zoonotic spillover to humanity,” they conclude.

In any case, it should be recognized that the bat SARS-associated coronavirus will continue to spread to humans. The possibility of another deadly pandemic is certainly rare. However, these possibilities increase with the frequency of such spreads. Therefore, the scientific community must be vigilant.

*Important Notices

bioRxiv It publishes preliminary, non-peer reviewed scientific reports and should not be considered conclusive and should not guide clinical practice / health-related behavior or be treated as established information.