[Development of a SPA-ELISA method for detecting anti-coronavirus IgG antibodies in serum samples from fulvous fruit bats].

Objective: To develop an simple and sensitive method for detecting anti-coronavirus IgG antibodies in bat sera based on enzyme-linked immunosorbent assay (ELISA).

Methods: A commercial ELISA kit for detecting SARS-CoV antibody was modified for detecting coronavirus antibodies in bat serum samples. The second antibody in the kit was replaced with horseradish peroxidase-conjugated protein-A (HRP-SPA) based on the characteristics of binding between Staphylococcus aureus protein A (SPA) and mammal IgG Fc fragment. The sera of 55 fulvous fruit bats (Rousettus dasymallus) were tested using the SPA-ELISA.

Results: The test results of the positive and negative controls in the kit and the serum samples from convalescent ;patient were consistent with expectation. Coronavirus antibody was detected in 2 out of the 55 bat serum samples. Serum neutralization test confirmed the validity of the SPA-ELISA method.

Conclusion: This SPA-ELISA method is applicable for detecting coronavirus antibody in bat sera.