SARS-CoV-2 in dogs: gamma variant and its transmission from humans in Ciudad de Buenos Aires, Argentina

Abstract

This article explores SARS-CoV-2 infection in dogs that have had close contact with humans diagnosed with COVID in Argentina. Affirmative molecular identification of the virus was achieved through RT-PCR analysis of oropharyngeal and rectal swabs from the dog as well as a nasal swab from the guardian. Positive results for the dog were confirmed through a LAMP/CRISPR assay and real time PCR. SARS-CoV-2 genomic RNA was successfully obtained from these samples, and the analysis of a partial sequence of the spike gene (ranging from amino acid 428 to 750) allowed us to classify both genomic sequences as Gamma variants, with a single amino acid variation in position 726. We evaluated the specific humoral immune response of the dog by an indirect ELISA using the Argentinian kit COVID AR IgG ELISA test adapted for domestic dogs, and pseudo-neutralization conducted with SARS-CoV-2 pseudotyped particles. We also evaluated the specific cellular immune response of the dog through a lymphoproliferation assay, using purified spike protein as specific stimulus. This work provides evidence of the human-to-dog transmission of SARS-CoV-2 in Argentina, underscoring the One Health concept and reinforcing surveillance methods in pets.