Bat-associated coronavirus found in pigs in the Iberian Peninsula: insights into potential cross-species transmission.

Coronaviruses (CoVs) are a diverse group of RNA viruses that affect both human and animal health. Swine populations are particularly relevant in the ecology of CoVs, acting as potential intermediate hosts for zoonotic transmission. This study aimed to assess the occurrence of CoVs in farmed pigs in Portugal and Spain. A total of 400 fecal samples were collected from pigs in northern Portugal and northern Spain and screened using a broad-spectrum pan-CoV nested RT-PCR assay. Of these, 18 samples (4.5%) tested positive for CoV, and phylogenetic analyses confirmed their classification within the Alphacoronavirus genus. The detected sequences shared high nucleotide identity with bat-associated Alphacoronaviruses from Portugal, Spain, Italy, and the United Kingdom, emphasizing the importance of continued research on the role of bats in the transmission cycle and the zoonotic potential of Alphacoronaviruses. These findings highlight the importance of ongoing surveillance in swine populations to monitor emerging CoV strains and assess potential zoonotic risks.