Evolutionary rate of SARS-CoV-2 increases during zoonotic infection of farmed mink
Authors:
Ashleigh F. Porter (1*), Damian F.J. Purcell (1), Benjamin P. Howden (1,2), Sebastian Duchene (1*).
Affiliations:
- Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia.
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia.
*Corresponding author. Email: [email protected], [email protected]
Abstract:
To investigate genetic signatures of adaptation to the mink host, we characterized the rate heterogeneity in mink-associated SARS-CoV-2. In 2020, the first detected anthropozoonotic spillover event of SARS-CoV-2 occurred in mink farms throughout Europe and North America. Both spill-back of mink-associated lineages into the human population and spread into surrounding wildlife was reported, highlighting the potential formation of a zoonotic reservoir. Our findings suggest the evolutionary rate of SARS-CoV-2 underwent an episodic increase upon introduction to the mink host before returning to the normal range. Furthermore, SARS-CoV-2 lineages could have circulated in the mink population for a month before detection, and during this period, evolutionary rate estimates of 6.57 ×10^(-3) could yield an 8-fold increase of mutations compared to the evolutionary rate of SARS-CoV-2 in humans. We suggest that SARS-CoV-2 undergoes a brief, but significant, increase in evolutionary rate in response to greater selective pressures during species jumps, emphasizing the necessity of monitoring zoonotic SARS-CoV-2 infections.
One-Sentence Summary:
In 2020, SARS-CoV-2 outbreaks were reported in mink farms. During this period of adaptation, the evolutionary rate of SARS-CoV-2 increased for a short interval.
Mink_MS.pdf (2.4 MB)