Susceptibility of sheep to experimental co-infection with the ancestral lineage of SARS-CoV-2 and its alpha variant

• Published in: Emerging microbes & infections Vol. 11; no. 1; pp. 662 - 675
• Main Authors: Gaudreault, Natasha N., Cool, Konner, Trujillo, Jessie D., Morozov, Igor, Meekins, David A., McDowell, Chester, Bold, Dashzeveg, Carossino, Mariano, Balaraman, Velmurugan, Mitzel, Dana, Kwon, Taeyong, Madden, Daniel W., Artiaga, Bianca Libanori, Pogranichniy, Roman M., Roman-Sosa, Gleyder, Wilson, William C., Balasuriya, Udeni B. R., García-Sastre, Adolfo, Richt, Juergen A.
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 01-12-2022; Taylor & Francis Ltd; Taylor & Francis Group
• Subjects: Animals; co-infection; Coinfection - veterinary; Coronaviruses; COVID-19 - veterinary; Disease transmission; Infections; ovine; ruminant; SARS-CoV-2; Severe acute respiratory syndrome coronavirus 2; Sheep; Sheep - virology; susceptibility; transmission; SARS-CoV-2; ruminant; susceptibility; transmission; co-infection; ovine; sheep
• ISSN: 2222-1751; 2222-1751
• DOI: 10.1080/22221751.2022.2037397

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for a global pandemic that has had significant impacts on human health and economies worldwide. SARS-CoV-2 is highly transmissible and the cause of coronavirus disease 2019 in humans. A wide range of animal species have also been shown to be susceptible to SARS-CoV-2 by experimental and/or natural infections. Sheep are a commonly farmed domestic ruminant that have not been thoroughly investigated for their susceptibility to SARS-CoV-2. Therefore, we performed in vitro and in vivo studies which consisted of infection of ruminant-derived cells and experimental challenge of sheep to investigate their susceptibility to SARS-CoV-2. Our results showed that sheep-derived kidney cells support SARS-CoV-2 replication. Furthermore, the experimental challenge of sheep demonstrated limited infection with viral RNA shed in nasal and oral swabs at 1 and 3-days post challenge (DPC); viral RNA was also detected in the respiratory tract and lymphoid tissues at 4 and 8 DPC. Sero-reactivity was observed in some of the principal infected sheep but not the contact sentinels, indicating that transmission to co-mingled naïve sheep was not highly efficient; however, viral RNA was detected in respiratory tract tissues of sentinel animals at 21 DPC. Furthermore, we used a challenge inoculum consisting of a mixture of two SARS-CoV-2 isolates, representatives of the ancestral lineage A and the B.1.1.7-like alpha variant of concern, to study competition of the two virus strains. Our results indicate that sheep show low susceptibility to SARS-CoV-2 infection and that the alpha variant outcompeted the lineage A strain.