Rapid Detection of Staphylococcal Enterotoxins

A wide range of methods are available for a complete Staphylococcal enterotoxin (SET) analysis from purification and concentration of the five different serologic groups (A-E) to identification of each group.

Staphylococcal intoxication is a common cause of foodborne disease outbreaks in many countries. Such intoxication results from ingestion of SET, produced by toxigenic strains of Staphylococcus aureus. There are several types of SET of which A, B, C, D, and E are most frequently linked to food poisoning. SET has almost total resistance to dehydration, proteolytic enzymes, and heat treatment. Common foods prone to staphylococcal food poisoning include meat and poultry, egg, mixed salads, cream pastries and pies, milk, and other dairy products. In many countries SETs are considered to be the second or third most common source of food poisoning outbreaks.

Traditional detection methods are costly, laborious, and lack the level of sensitivity required for industrial use. Raisio Diagnostics (Turku, Finland) offers a wide range of methods for a complete SET analysis from purification and concentration of the five different serological groups (A-E) to identification of each group. The European Union (EU) Community Reference Laboratory (CRL) for milk and milk products has recognized the value of the Transia plate set, and is recommending the use of this Raisio product for official testing of milk and dairy products.

Immunoaffinity columns (IAC) are used for purification and concentration of staphylococcal enterotoxins from various foods prior to detection with Transia SET methods. These columns are used as an alternative to dialysis methods.

The Transia IAC Staphylococcal enterotoxin assay is based on an antibody-antigen reaction. The solid support is a gel coupled with anti-staphylococcal enterotoxin antibodies that bind specifically to enterotoxins A, B, C, D, and E. The eluent from the column can be used directly in the Transia SET tests. The use of an immunoaffinity column improves the sensitivity of the method and reduces the risk for false-positives by minimizing potential cross-reacting substances from the sample. The IAC method is much faster than the dialysis method requiring only two hours for processing the samples up to the analysis step. If the final outcome of the test is negative the columns can be re-used up to three times to save waste and money.

Extreme sensitivity with a detection limit down to 0.1 ng enterotoxins/g sample is achieved by combining Transia IAC with the other Transia detection methods including the Transia plate set, Transia plate set plus, and Transia id set. For running smaller number of samples, a Transia tube set is also available. A Transia enzyme-linked immunosorbant method is also available.


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