Acta Agriculturae Zhejiangensis ›› 2025, Vol. 37 ›› Issue (10): 2057-2065.DOI: 10.3969/j.issn.1004-1524.20250139

• Animal Science • Previous Articles     Next Articles

Establishment and application of an indirect ELISA method for detecting antibodies against fowlpox virus ORF127 protein

HUA Jionggang1(), ZHU Yinchu1, YE Jialin2, ZHANG Cun1, CHEN Liu1, NI Zheng1, FU Yuan1, HUO Suxin1, YUN Tao1,*()   

  1. 1. Zhejiang Key Laboratory of Livestock and Poultry Biotech Breeding, Key Laboratory of Livestock and Poultry Resources (Poultry) Evaluation and Utilization, Ministry of Agriculture and Rural Affairs, Zhejiang Engineering Research Center for Poultry Breeding Industry and Green Farming Technology, Institute of Animal Husbandry and Veterinary Sciences, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
    2. International Division, Hangzhou High School, Hangzhou 310020, China
  • Received:2025-02-24 Online:2025-10-25 Published:2025-11-13

Abstract:

To establish a rapid and accurate method for detecting fowlpox virus (FPV) antibodies, this study cloned the antigenic epitope region of FPV ORF127 gene into the pET-28a(+) prokaryotic expression vector. The truncated FPV ORF127 protein was successfully expressed and purified. Using this recombinant protein as a coating antigen, an indirect ELISA was developed through systematic optimization of reaction parameters. The method was comprehensively validated, including specificity, sensitivity, repeatability tests, and clinical serum sample detection. The results showed that the optimal reaction conditions for the indirect ELISA were as follows: coating antigen concentration of 10 μg·mL-1, serum dilution of 1∶100, and enzyme-labeled secondary antibody dilution of 1∶25 000. Specificity tests revealed that except for FPV-positive serum, no cross-reactions were observed with positive sera against six other viruses (Newcastle disease virus, H9 subtype avian influenza virus, infectious bursal disease virus, infectious laryngotracheitis virus, fowl adenovirus type 4, and turkey herpesvirus). Sensitivity tests showed that FPV-positive serum remained detectable at a dilution of 1∶800. Reproducibility tests demonstrated that the intra-assay and inter-assay coefficients of variation were 1.81%-7.07% and 2.12%-7.16%, respectively, both below 10%. Clinical serum sample testing showed a total positivity rate of 79.4% (143/180) among 180 samples. These results indicate that the established indirect ELISA method exhibits high specificity, sensitivity, reproducibility, and stability. It can provides a reliable tool for detecting FPV antibodies in vaccinated flocks and supporting FPV epidemiological investigations.

Key words: fowlpox virus, ORF127 protein, indirect ELISA, antibody

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