Screening for SARS-CoV-2 in different sheep and goat breeds in Türkiye using in-house ELISAs and real-time PCR.

SARS-CoV-2, a type of coronavirus that infects humans, uses its spike protein to bind to the ACE-2 receptor during cell entry, which is highly conserved among vertebrates. Therefore, various animal species are thought to be susceptible to SARS-CoV-2 infection. In this study, we aimed to investigate the presence of SARS-CoV-2 RNA in swab samples using real-time PCR and anti-S1 IgG antibodies in serum samples using an in-house ELISA using recombinant S1 protein. Swab and serum samples were collected from different sheep and goat breeds living in different locations of Türkiye. In order to eliminate false seropositivity due to possible cross-reactions between bovine coronavirus (BCoV) and SARS-CoV-2 spike proteins, seropositive samples were further investigated by another ELISA using a SARS-CoV-2 spike specific peptide. According to the results of ELISA detecting anti-S1 IgG antibodies, 23 sheep serum samples (6.74%; 23/341) and 17 goat serum samples (22.07%; 17/77) were seropositive. After the analysis of these seropositive samples by peptide-ELISA, seroprevalence rates decreased to 3.81% (13/341) in sheep and 3.89% (3/77) in goats. According to the real-time PCR results, no SARS-CoV-2 RNA was detected in swab samples of sheep and goats. In conclusion, although SARS-CoV-2 specific antibodies were detected in sheep and goats, SARS-CoV-2 RNA was not detected and this does not suggest an important role for sheep or goats in the transmission of SARS-CoV-2 to other hosts, including humans.