Chinese Horseshoe Bats Are Reservoirs of SARS

Rhinolophus bats related to the evolution of coronaviruses
bat hanging from a tree limb

A new study examined genetic sequences of hundreds of coronaviruses found in bats in China, but ‘cannot’ pinpoint the origin of the SARS-CoV-2 coronavirus, which is causing the COVID-19 disease pandemic.

Bats are presumed reservoirs of diverse coronaviruses (CoVs) including progenitors of Severe Acute Respiratory Syndrome (SARS)-CoV identified in 2002 and novel SARS-CoV-2.

But, this non-peer-reviewed study posted on May 31, 2020, does identify the genus Rhinolophus, also known as Chinese horseshoe bats, as crucial to the evolution of coronaviruses.

“It seems that by phylogeographic, historical, evolutionary bad luck, Rhinolophus ends up being the major reservoir for SARS related coronaviruses,” says study co-author Dr. Peter Daszak.

However, the evolution and diversification of these coronaviruses remain poorly understood. 

These researchers used a Bayesian statistical framework and sequence data from all known bat-CoVs (including 630 novel CoV sequences) to study their macroevolution, cross-species transmission, and dispersal in China. 

They found that host-switching was more frequent and across more distantly related host taxa in alpha- than beta-CoVs, and more highly constrained by phylogenetic distance for beta-CoVs.

And showed that inter-family and -genus switching is most common in Rhinolophidae and the genus Rhinolophus. 

These analyses identify the host taxa and geographic regions that define hotspots of CoV evolutionary diversity in China that could help target bat-CoV discovery for proactive zoonotic disease surveillance. 

Finally, this study presents a phylogenetic analysis suggesting a likely origin for SARS-CoV-2 in Rhinolophus spp. Bats.

These authors declared no competing interest.

SARS-CoV origin news is published by CoronavirusToday.