High sensitivity chemiluminescence enzyme immunoassay for detecting staphylococcal enterotoxin C1 and its application in multi-matrices

Abstract

Staphylococcal enterotoxins (SEs) serve as the primary cause of staphylococcal food poisoning and other foodborne intoxications. Among them, staphylococcal enterotoxin C (SEC) has the highest prevalence in dairy products, leading to multiple outbreaks all around the world. Thus, it is of great significance to develop a highly sensitive, highly specific and easy to operate chemiluminescent sandwich enzyme immunoassay (CLEIA) for detecting staphylococcal enterotoxin C (SEC1). We selected two pairs of anti-SEC1 monoclonal antibodies (mAbs) (SEC1-G8 and SEC1-C4), and a chemiluminescent sandwich enzyme immunoassay (CLEIA) was constructed. This approach can detect SEC1 within a concentration spectrum of 3.2–4000 pg/mL, with the detection limit being 2.1 pg/mL. At three concentrations (3.2, 20, and 400 pg/mL), both the intra- and inter-assay coefficient variations were coming in at 6.31 % and 11.2 % respectively. No cross-reaction was noticed in the SEA, SEB, and SED tests. SEC1 was successfully detected by employing the CLEIA method in spiked matrices and commercial samples, and the average recovery rate ranges from 81.6 % to 108.1 %. Therefore, the highly sensitive, SEC1- specific, and easy-to-operate CLEIA could be a useful tool in the near future for quantifying SEC1 in public health and food safety.

Keywords

• Staphylococcal enterotoxin C1
• Chemiluminescence enzyme immunoassay
• Sensitivity
• Staphylococcal food poisoning
• Application
• Food safety