Establishment and application of an indirect enzyme-linked immunosorbent assay based on tandem expression PrgH-PagN protein to detectinfection in ducks.

Abstract

an important foodborne zoonotic pathogen, can be transmitted both vertically and horizontally. It is difficult to control and effectively decontaminate, and it poses a serious threat to food safety. Therefore, to prevent the spread of salmonellosis, there is an urgent need for a rapid, accurate and sensitive assay to detect the prevalence ofin duck flocks. In this study, we utilized biological software to predictively screen the highly conserved-specific proteins SpiC, PrgH and PagN. The recombinant proteins PrgH, SpiC, PagN were screened for sensitivity based on individual proteins and pairwise combinations (SpiC + PrgH, SpiC + PagN and PrgH + PagN). A specific and sensitive dual-protein combination, PrgH + PagN, was used as an antigen. Subsequently, PrgH-PagN was produced by tandem expression and employed as the coating antigen in an indirect ELISA (iELISA) for detectingantibodies in duck serum. The optimal antigen coating concentration was determined to be 1 μg/ml, with a critical value of OD = 0.154. The cross-reactivity test results showed no evidence of cross-reactivity with known positive serums from ducks infected with. Enteritidis,Typhimurium,. Kottbus,,or. Screening of 611 duck serums was performed to determine an overall positive rate of 22.09%. The final compliance rate of 93.1% was determined by comparison with that of the commercial kit. In conclusion, the PrgH-PagN-iELISA established in the present study was an accurate and reliable method, with high sensitivity and specificity for detecting antibody responses to systemicinfections in ducks.