Establishment of an indirect ELISA method for detecting Salmonella infection based on Sptp protein in poultry

Salmonella is a very important zoonotic pathogen that causes considerable economic losses and endangers food safety in poultry industry. So it is essential to develop an efficient diagnostic method to detect Salmonella infection in poultry. The present study established a novel indirect ELISA based on SptP protein as coating antigen to detect specific anti-Salmonella antibodies in poultry. The established SptP-ELISA exhibited high specificity and sensitivity, capable of detecting anti-SptP antibodies in chicken sera with a maximum dilution of 1:1600 based on the cut-off value. The intra- and inter-assay coefficients of variation (CV) for the SptP-ELISA were both below 10%, which satisfy the requirements. Comparison with clinical serum samples revealed that the established SptP-ELISA and commercial Salmonella ELISA kit displayed completely consistent detection results. In summary, the established SptP-ELISA is a convenient and reliable method for detecting anti-Salmonella antibodies, and could monitor the epidemiology of Salmonella infection in poultry industry.