Coronaviruses Associated with the Superfamily Musteloidea

Abstract

Among the animal superfamily Musteloidea, which includes those commonly known as mustelids, naturally occurring and species-specific alphacoronavirus infections have been observed in both mink (Mustela vison/Neovison vison) and domestic ferrets (Mustela putorius furo). Ferret systemic coronavirus (FRSCV), in particular, has been associated with a rare but fatal systemic disease. In recent months, it has become apparent that both minks and ferrets are susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a betacoronavirus and the cause of the coronavirus disease 2019 (COVID-19) pandemic. Several mink farms have experienced SARS-CoV-2 outbreaks, and experimental models have demonstrated susceptibility of ferrets to SARS-CoV-2. The potential for pet ferrets to become infected with SARS-CoV-2, however, remains elusive. During the 2002-2003 SARS epidemic, it was also apparent that ferrets were susceptible to SARS-CoV and could be utilized in vaccine development. From a comparative standpoint, understanding the relationships between different infections and disease pathogenesis in the animal superfamily Musteloidea may help elucidate viral infection and transmission mechanisms, as well as treatment and prevention strategies for coronaviruses.

Keywords: Musteloidea; SARS-CoV-2; coronavirus; ferret coronavirus; mink; mustelids.

FIG 1

Coronaviruses of minks and ferrets. Phylogenetic analysis based on the spike protein sequences of representative alpha- and betacoronaviruses, including viruses infecting mustelids. A maximum likelihood (ML) phylogenetic tree was generated based on selected spike protein sequences. Bootstrap values shown at nodes were calculated from 1,000 replicates. The tree is drawn to scale, with branch lengths measured in the number of substitutions per site. SARS-CoV-2 strains in red font denote isolates from minks. Strains of SARS-CoV that were used to experimentally infect ferrets are indicated by an asterisk.

FIG 2

Comparison of mouse, ferret, and nonhuman primates as animal models to study highly pathogenic human coronaviruses. The comparative analysis is based mostly on studies on SARS-CoV-2 infection; however, some parameters are applicable to other human coronaviruses such as SARS-CoV and MERS-CoV. The asterisk denotes that nonhuman primates (NHPs) comprises macaques and African green monkeys.