Detection of staphylococcal enterotoxins A, B, C, D, and E in foods by radioimnunoassay, using staphyloccal cells containing protein A as immunoadsorbent

Abstract

A sensitive radioimmunoassay utilizing Staphylococcus aureus cells containing protein A as a coprecipitant was developed for the detection and quantitation of staphylococcal enterotoxins A, B, C, D, and E in a variety of foods. The enterotoxins were extracted from the foods by a simple and rapid procedure. The sensitivity of the assay is 1.0 ng or less of enterotoxin per g of food.

Staphylococci in milk and milk products

“…However, methods have been developed which are more sensitive and rapid. These include radioimmunoassay (RIA) (Lindroth & Niskanen 1977;Miller et al 1978), enzyme-linked immunosorbent assay (ELISA) (Notermans et al 1978;Kuo & Silverman 1980), reversed passive haemagglutination assay (RPHA) (Morse & Mah 1967;Yamada et al 1977). They did not come into earlier routine use, however, for various technical reasons such as the requirement for very highly purified reagents which until recently were difficult to obtain and prohibitively expensive and also, in the case of RIA, the need for specialized equipment to measure the radioactive uptake of samples.…”

Monoclonal antibodies to staphylococcal enterotoxins B and C: cross-reactivity and localization of epitopes on tryptic fragments

“…The nontrypsinized material contained some nicked material which is very similar in molecular weight to the fragments generated by trypsin digestion; this native nicking has been observed by other investigators (20). lodinated toxins for the radioimmunoassays (RIAs) were prepared by the method of Miller et al (13), using Na125I (New England Nuclear Corp., Boston, Mass.) and 20 ng of chloramine-T per ml.…”

Evaluation of an alternative extraction procedure for enterotoxin determination in dairy products

“…The quantity of enterotoxin present in the foods involved in food-poisoning outbreaks may vary considerably from less than 1 ng g −1 to more than 50 ng g −1 (Bergdoll 1991). Different immunological methods have been proposed for detecting staphylococcal enterotoxins, including immunodiffusion assays (Casman et al 1979), radioimmunoassays (Miller et al 1978;Janin et al 1985) and enzyme linked immunosorbent assays Correspondence to: Dr A. Meyrand,Unité de Microbiologie Alimentaire et Prévisionnelle,É cole Nationale Vétérinaire de Lyon,1 avenue Bourgelat,B.P. 83,F.…”