Are pangolins the intermediate host of the 2019 novel coronavirus (SARS-CoV-2)?

Abstract

The outbreak of a novel corona Virus Disease 2019 in the city of Wuhan, China has resulted in more than 1.7 million laboratory confirmed cases all over the world. Recent studies showed that SARS-CoV-2 was likely originated from bats, but its intermediate hosts are still largely unknown. In this study, we assembled the complete genome of a coronavirus identified in 3 sick Malayan pangolins. The molecular and phylogenetic analyses showed that this pangolin coronavirus (pangolin-CoV-2020) is genetically related to the SARS-CoV-2 as well as a group of bat coronaviruses but do not support the SARS-CoV-2 emerged directly from the pangolin-CoV-2020. Our study suggests that pangolins are natural hosts of Betacoronaviruses. Large surveillance of coronaviruses in pangolins could improve our understanding of the spectrum of coronaviruses in pangolins. In addition to conservation of wildlife, minimizing the exposures of humans to wildlife will be important to reduce the spillover risks of coronaviruses from wild animals to humans. Author summaryRecently, a novel coronavirus, SARS-CoV-2, caused a still ongoing pandemic. Epidemiological study suggested this virus was associated with a wet market in Wuhan, China. However, the exact source of this virus is still unknown. In this study, we attempted to assemble the complete genome of a coronavirus identified from two groups of sick PLOS PATHOGENSMalayan pangolins, which were likely to be smuggled for black market trade. The molecular and evolutionary analyses showed that this pangolin coronavirus we assembled was genetically associated with the SARS-CoV-2 but was not likely its precursor. This study suggested that pangolins are natural hosts of coronaviruses. Determining the spectrum of coronaviruses in pangolins can help understand the natural history of coronaviruses in wildlife and at the animal-human interface, and facilitate the prevention and control of coronavirus-associated emerging diseases.

The PRRA insert at the S1/S2 site modulates cellular tropism of SARS-CoV-2 and ACE2 usage by the closely related Bat raTG13

“…A newly reported bat RmYN02 shares 93.3% nucleotide identity with SARS-CoV-2 genomewide and 97.2% identity in the 1ab gene (Zhou et al, 2020a). Besides bat CoVs, pangolin/GD/2019 CoV and pangolin/GX/P5L/2017 CoV share up to 90% and 85.2% sequence identity with SARS-CoV-2, respectively (Liu et al, 2020;Zhang et al, 2020). While the origin of the novel coronavirus appears to be in bat reservoirs, there is still no definitive evidence of an intermediate host that could have transmitted the virus to humans.…”

A Comprehensive Classification of Coronaviruses and Inferred Cross-Host Transmissions

“…Pangolins were suggested to be involved in the species jump of SARS-CoV-2 to humans (37,42). However, more recent studies have disputed this notion (37,43,44). Finally, while the links among Hominidae, Mustelidae (minks), and Felidae (tigers) were deduced, it remains to be seen how SARS-CoV-2 viruses were transmitted among them.…”

Might SARS‐CoV‐2 Have Arisen via Serial Passage through an Animal Host or Cell Culture?

“…It found that the novel coronavirus appears to be far more adapted to human ACE2 receptors than those found in bats, which is unexpected given that bats are the virus's assumed source, and which lead the lead research to observe that SARS-CoV-2 was perfectly adapted to infect humans since its first contact with us, and had no apparent need to for any adaptive evolution at all. [46] Although the novel coronavirus also appears to have a high affinity for the pangolin ACE2 receptor, [47] phylogenetic analysis of the neutral sites that best determine shared heritage [48] and a distinctive amino acid sequence both indicate that pangolins are unlikely to have served as an intermediate host, [47] so this affinity is likely due to the convergent motifs that often mark viral evolution and not shared heritage. The unexpected immediate www.advancedsciencenews.com www.bioessays-journal.com affinity for humans was also reflected by another preprint, which observed that SARS-CoV-2 appeared just as adapted to humans at the very start of its epidemic as SARS-CoV was in the latest stages of its emergence, [49] an unexpected finding since viruses are expected to mutate substantially as they acclimate to a new species.…”