Serum samples from uninfected SPF cats were negative. unknown SARS-CoV-2 exposure was low during the first coronavirus disease wave, our data stress the need for development of continuous serosurveillance for SARS-CoV-2 in these 2 animal species. strong class=”kwd-title” Keywords: severe acute respiratory syndrome coronavirus 2, SARS-CoV-2, coronaviruses, viruses, coronavirus disease, COVID-19, respiratory infections, cats, dogs, serologic screening, ELISA, computer virus neutralization, receptor-binding domain name, nucleocapsid protein, zoonoses, the Netherlands A novel human coronavirus (HCoV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in Wuhan, China, during December 2019 and caused a severe pandemic of coronavirus disease (COVID-19) ( em 1 /em , em 2 /em ). As of January 2021, SARS-CoV-2 had spread to 223 countries and caused 88 million infections, which occurred by human-to-human transmission and mostly affected elderly and immunocompromised persons ( em 3 /em ). SARS-CoV-2 is usually a zoonotic computer virus and was shown able to infect many animal species, such as cats, dogs, ferrets, fruit bats, hamsters, and several nonhuman primates under experimental condition ( em 4 /em C em 6 /em ). Recently, transmission of SARS-CoV-2 from humans to cats and dogs shown by viral RNA or antibody detection has been reported, resulting in asymptomatic infections in dogs, and symptomatic and asymptomatic Rabbit Polyclonal to ADORA1 infections in cats ( em 7 /em C em 15 /em ). There is currently no evidence that pets play a role in spread of the computer virus. Nevertheless, close contacts between owners and domestic pets and interactions between dogs and cats from different households raise the question about the role of these Abemaciclib Metabolites M2 animals in SARS-CoV-2 transmission. Diagnosis of SARS-CoV-2 is currently made by using molecular assays, such as real-time PCR. However, viral nucleic acid is only detectable within a limited timeframe after contamination, and serologic screening of SARS-CoV-2Cspecific antibodies in cats and dogs is needed for insights into the prevalence of this infection and possible modes of transmission (human-to-animal, animal-to-animal, and animal-to-human). We developed and validated SARS-CoV-2Cspecific Abemaciclib Metabolites M2 serologic assays. Serum samples were first tested with ELISAs by using different antigens, including spike protein subunit (S1) of endemic feline Abemaciclib Metabolites M2 and canine coronaviruses and SARS-CoV-2 antigens (S1, receptor binding domain name [RBD], and nucleocapsid [N] protein), and subsequently analyzed by using computer virus neutralization titer (VN) assays with SARS-CoV-2 spike pseudotyped computer virus. Using these assay platforms, we conducted serosurveillance study of SARS-CoV-2 in cats and dogs of unknown SARS-CoV-2 exposure during the first wave of COVID-19 pandemic (AprilCMay 2020) in the Netherlands. Materials and Methods Serum Samples Cat and doggie serum samples collected during 2019 (preCCOVID-19 cohort, n = 45 each) were obtained from the serum lender of Utrecht University or college (Utrecht, the Netherlands). Paired and postinfection serum samples of feline coronavirus (FCoV) type ICinfected specific pathogen-free (SPF) cats (n = 9) were obtained from SPF cats infected with FCoV strain UU2 or RM in a previous study ( em 16 /em ). The SARS-CoV-2Cexposed cohort consisted of 44 serum samples from stray cats roaming on SARS-CoV-2Cpositive mink farms ( em 17 /em ) and 1 serum sample of a doggie from a COVID-19Cconfirmed household. The 2020 cohort is composed of domestic cat and doggie serum or plasma samples (n = 500 each) that were sent to the University or college Veterinary Diagnostic Laboratory or the Veterinary Microbiological Diagnostic Center at Utrecht University or college for routine diagnostics during AprilCMay 2020. Data on SARS-CoV-2 exposure of these animals was not available. All samples were stored at ?20C until use and heat-inactivated at 56C for 30 min before use. Antigen Preparation We produced streptavidinCtagged SARS-CoV-2 S1 and RBD proteins in eukaryotic cells as explained ( em 18 /em , em 19 /em ), and cloned and similarly produced streptavidin-tagged bovine coronavirus (BCoV) S1 and HCoV-229E S1. SARS-CoV-2 N protein was obtained from Sino Biological (https://www.sinobiological.com). We produced mouse Fc-tagged FCoV type I S1, FCoV type II S1, or BCoV S1 proteins as explained ( em 20 /em ). Vesicular stomatitis computer virus (VSV) pseudotyped with SARS-CoV-2 S protein (SARS2-VSV) was prepared as explained ( em 18 /em ) and titrated on Vero E6 cells. ELISA We first screened samples from your 3 cohorts with indirect ELISAs for.