Bacteris Toxins

Staphylococcal Enterotoxins Detection and Identification

When large numbers of enterotoxigenic staphylococci grow in foods, they may elaborate enough toxin to cause food poisoning after the foods are ingested. The most common symptoms of staphylococcal food poisoning, which usually begin 2-6 h after contaminated food is consumed, are nausea, vomiting, acute prostration, and abdominal cramps. To date, 8 enterotoxins (types A, B, C1, C2, C3, D, E, and H) have been identified as distinct serological entities. Current methods to detect enterotoxins use specific polyclonal or monoclonal antibodies (33,42,43).

Detection Methods and Techniques
1. Microslide gel double diffusion technique
2. Radioimmunoassay agglutination (RIA)
3. Enzyme-linked immunosorbent assay (ELISA)
- "double antibody sandwich" ELISA is the method of choice, because reagents are commercially available in polyvalent and monovalent formats for both toxin screening and serotype specific identification
- An automated enzyme-linked fluorescent immunoassay (ELFA) has been developed and is commercially available. This method has undergone specificity and sensitivity evaluations and has proven to be an effective serological system for the identification of staphylococcal enterotoxin in a wide variety of foods
4. Other methods, which have been used in the identification of the staphylococcal enterotoxins and may have application in foods, are the T-cell proliferation assay, and polyacrylamide gel electrophoresis (PAGE) combined with Western blotting

Summary

Microslide gel double diffusion precipitation test, two manual ELISAs [TecraTM, TransiaTM], an automated qualitative "enzyme-linked fluorescent immunoassay" [ELFATM, VidasTM], and sodium dodecyl sulfate-polyacrylamide gel electrophoresis [SDS-PAGE]-immunoblotting) for the identification of staphylococcal enterotoxin from isolates and from foods. - most common and often practiced and used


Recommended for routine analysis of foods for staphylococcal enterotoxin is the use, initially, of two different polyvalent ELISA kits



Known limits that causes food borne illness

When large numbers of enterotoxigenic staphylococci grow in foods, they may elaborate enough toxin to cause food poisoning after the foods are ingested. The most common symptoms of staphylococcal food poisoning, which usually begin 2-6 h after contaminated food is consumed, are nausea, vomiting, acute prostration, and abdominal cramps. To date, 8 enterotoxins (types A, B, C1, C2, C3, D, E, and H) have been identified as distinct serological entities. Current methods to detect enterotoxins use specific polyclonal or monoclonal antibodies (33,42,43).