A recently discovered coronavirus in Brazilian bats has raised concerns due to its similarity to SARS-CoV-2, the virus responsible for COVID-19. This potential zoonotic threat was identified by a collaborative research team from Japan and Brazil in a preliminary study made public last week.
The new virus, known as BRZ batCoV, was found in a species called the Parnell”s mustached bat (Pteronotus parnellii). Researchers conducted genetic sequencing on samples collected from 70 bats across three sites in Brazil between May and August 2019. The analysis revealed that BRZ batCoV is genetically distinct from other known coronaviruses, representing a new subgenus within the betacoronavirus family.
One significant finding is that BRZ batCoV shares a crucial feature with SARS-CoV-2: a functional furin cleavage site (FCS) at the S1/S2 junction of its spike protein. This similarity is concerning because the FCS in SARS-CoV-2 facilitates its ability to infect human cells. The FCS in the newly discovered virus differs from that of SARS-CoV-2 by only one amino acid.
Experts are cautious about the implications of this discovery. The FCS is a hallmark that has been identified in several bat betacoronaviruses, indicating that such features may easily emerge in these viruses. The low level of surveillance in Brazil and other parts of the Americas heightens the risk that BRZ batCoV and similar viruses have been circulating unnoticed.
While the findings have not yet undergone peer review, the researchers emphasize the importance of this work in understanding the diversity and potential zoonotic risks associated with bat coronaviruses. They caution that although the presence of an FCS is significant, the actual infectivity of BRZ batCoV has not been assessed directly, limiting conclusions about its threat to humans.
The study highlights the necessity for enhanced surveillance of coronaviruses in bats, particularly given their history as reservoirs for zoonotic diseases that can lead to pandemics. The authors conclude that their research adds valuable insights into the phylogenetic and functional diversity of bat coronaviruses, underscoring their potential impact on public health.
