SPA-ELISA检测棕果蝠血清冠状病毒抗体的研究

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

目的建立一种敏感、简便的检测蝙蝠血清冠状病毒抗体的方法。方法利用葡萄球菌A蛋白(SPA)能够与某些哺乳动物IgG抗体Fc段非特异性结合的特点,对市售人冠状病毒抗体ELISA试剂盒进行改造,建立SPA-ELISA法,使其适用于蝙蝠血清冠状病毒抗体的检测,并对采集到的55份棕果蝠血清冠状病毒抗体进行检测。结果用SPA-ELISA方法对人冠状病毒试剂盒中阳性与阴性对照、SARS病人恢复期血清、空白对照的检测都得到理想的结果,并从55份棕果蝠血清中检测出2例阳性,阳性率为3.64%(2/55),中和试验进一步证实了结果的真实性。结论所建立的方式适用于检测棕果蝠血清冠状病毒抗体。

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.