Serological Screening for Coronavirus Infections in Cats

Abstract

Coronaviruses (CoVs) are widespread among mammals and birds and known for their potential for cross-species transmission. In cats, infections with feline coronaviruses (FCoVs) are common. Several non-feline coronaviruses have been reported to infect feline cells as well as cats after experimental infection, supported by their ability to engage the feline receptor ortholog for cell entry. However, whether cats might become naturally infected with CoVs of other species is unknown. We analyzed coronavirus infections in cats by serological monitoring. In total 137 cat serum samples and 25 FCoV type 1 or type 2-specific antisera were screened for the presence of antibodies against the S1 receptor binding subunit of the CoV spike protein, which is immunogenic and possesses low amino acid sequence identity among coronavirus species. Seventy-eight sera were positive for antibodies that recognized one or more coronavirus S1s whereas 1 serum exclusively reacted with human coronavirus 229E (HCoV-229E) and two sera exclusively reacted with porcine delta coronavirus (PDCoV). We observed antigenic cross-reactivity between S1s of type 1 and type 2 FCoVs, and between FCoV type 1 and porcine epidemic diarrhea virus (PEDV). Domain mapping of antibody epitopes indicated the presence of conserved epitope(s) particularly in the CD domains of S1. The cross-reactivity of FCoV type 1 and PEDV was also observed at the level of virus neutralization. To conclude, we provide the first evidence of antigenic cross-reactivity among S1 proteins of coronaviruses, which should be considered in the development of serological diagnoses. In addition, the potential role of cats in cross-species transmission of coronaviruses cannot be excluded.

Screening for SARS‐CoV‐2 antibodies in convalescent plasma in Brazil: Preliminary lessons from a voluntary convalescent donor program

“…Donors approved by the medical examination had also to sign an informed consent form and undergo a series of tests: 38 and used for SARS-CoV studies. [39][40][41][42][43][44] All CPE-VNT procedures were performed in a Biosafety Level 3 laboratory, following World Health Organization recommendations. 45 Neutralizing antibody titers were transformed in natural logarithm (ln) for normal distribution.…”

Serological Screening of Influenza A Virus Antibodies in Cats and Dogs Indicates Frequent Infection with Different Subtypes

“…Sera with OD values higher than 5-fold of the OD value of the corresponding negative sera were considered positive. ELISA results are expressed as ratios of OD450 value of the analyzed sera and the positive cut-off values (OD450 value of serum/positive cut-off value)(38,39). All 7 HA or 7 HA1 proteins were coated on the same ELISA plates making it easy to screen and compare the OD values of individual sera in one assay.…”

Porcine deltacoronavirus nucleocapsid protein species-specifically suppressed IRF7-induced type I interferon production via ubiquitin-proteasomal degradation pathway

“…PDCoV is the emerging deltacoronavirus from swine and has spread in most countries. Under natural conditions, PDCoV is also positive in some cats, which was detected through sera reaction ( Zhao et al, 2019 ). The newly emerged PDCoV also could infect the calves, but without lesions or clinical disease ( Kwonil et al, 2017 ).…”