A novel Gaussia luciferase immunoprecipitation assay for the detection of Getah virus antibodies in pigs.

Getah virus (GETV), a mosquito-borne pathogen, causes fever, aseptic meningitis, and abortion across various animal species, including pigs, horses, and cattle. Its widespread prevalence in China has resulted in substantial economic losses to the pig industry and poses a growing threat to public health security. Currently, no effective vaccine or antiviral drug for GETV control in China underscores the urgent need for the development of a rapid and sensitive antibody detection method for large-scale screening. In this study, we established a luciferase immunoprecipitation system (LIPS) assay to detect GETV antibodies in pig serum, utilizing Gaussia luciferase (GLuc)-tagged E2 as a diagnostic antigen. After optimizing the reaction conditions for the GLuc-E2-based LIPS assay, we determined the optimal GLuc-E2 input to be 10^7 luminance units and the optimal serum dilution to be 1:100, achieving the highest P/N ratio. Using 106 GETV-positive and 325 GETV-negative pig serum samples, the cutoff value for the S/N ratio was determined to be 13.71, yielding 99.69 % specificity and 100 % sensitivity. This LIPS assay showed no cross-reactivity with antibodies against other major porcine pathogens, including African swine fever virus (ASFV), porcine reproductive and respiratory syndrome virus (PRRSV), Japanese encephalitis virus (JEV), pseudorabies virus (PRV), and porcine circovirus type 2 (PCV2). Furthermore, a seroprevalence surveillance of porcine GETV in Hebei Province, China, validated the utility of this GLuc-E2-based LIPS assay for the diagnosis of GETV infection. In conclusion, we have developed a LIPS assay for GETV antibody detection, which could serve as a reliable tool for GETV detection in both laboratory and field settings.