Double‐Antibody Sandwich Enzyme‐Linked Immunosorbent Assay for Detecting Feline Coronavirus Infection

OBJECTIVES: Double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) is a simple and accurate method for detecting viral pathogens. This study established a DAS-ELISA for the diagnosis of feline coronavirus (FCoV). METHODS: In this study, DAS-ELISA was performed using FCoV S-protein rabbit polyclonal and mouse monoclonal antibodies. The optimal reaction conditions were determined using the chessboard method. The specificity, repeatability and receiver operating characteristic (ROC) curve were used to verify the clinical application potential of the DAS-ELISA. RESULTS: The intra- and inter-assay %CVs were 3.90-14.10 and 2.55-11.02, respectively. In a preliminary specificity evaluation using 12 faecal samples each from cats infected with feline panleukopenia virus, feline calicivirus or feline herpesvirus, the DAS-ELISA showed no detectable cross-reactivity with any of these pathogens. The positive coincidence rate of DAS-ELISA and RT-PCR was 81.3%. The ROC curve showed that the sensitivity, specificity and ROC AUC were 81.3%, 80.0% and 0.861, respectively. CONCLUSION: Collectively, these results suggest that the developed DAS-ELISA can be used to detect FCoV pathogens in clinical samples. This study provides a selection method for the diagnosis of FCoV and a data supplement for epidemiological studies of FCoV.