Researchers from Switzerland, Costa Rica, and Germany carried out a study to understand which animals have the potential to be spillback reservoirs of the novel coronavirus.
Through their study, they found that SARS-CoV-2 only replicated efficiently in cultures grown from two species — the rhesus monkey and the cat.
Researchers said: “This is the first study employing an in vitro AEC culture repository composed of various domestic and wildlife animal species to assess the potential intermediate and spillback host reservoir spectrum of SARS-CoV-2.”
The researchers carried a whole-genome sequencing and found no evidence to suggest that the predominant SARS-CoV-2 strain (the D614G variant) had undergone mutational adaptation to be able to infect the rhesus macaque and cat.
Close surveillance of cats, monkeys, and closely-related species is warranted to understand these species as potential spillback reservoirs for the virus, the researchers said.
The researchers examined SARS-CoV-2 susceptibility in 12 mammalian species.
For the study, the researchers obtained post-mortem tracheobronchial airway tissue from companion animals (cat, dog), candidate animal models (rhesus macaque, ferret, and rabbit), livestock (pig, cattle, goat, llama, camel), and two bat species.
The researchers found that only tracheobronchial cells from the rhesus macaque and cat supported efficient replication of SARS-CoV-2.
The team observed a significant increase in viral RNA load at 72- and 96-hours post-infection in the rhesus macaque and cats, while the remaining species showed either a continuous or decreasing viral RNA load.
The team said that their findings, alongside the earlier documented spillover events, suggest that close surveillance of these animals, including closely-related species in the wild, in captivity, and in household settings is warranted.
A preprint version of the paper is available on the server bioRxiv*.