Using Reversed Passive Latex Agglutination Method to Detect Enterotoxigenic Staphylococcus aureus and Enterotoxin in Foods

HSI-CHIN KO AND *TSUI-YING CHANC

National Laboratories of Foods and Drugs, Department of Health, Executive Yuan, 161-2, Kuen Yang Street, Nang kang, Taipei, Taiwan, R.O.C.
*College of life Science, National Tsing Hua University, Hsinchu, Taiwan, R.O.C.

ABSTRACT

   A total of 196 food samples including rice products, meat products and dairy products, and 169 food poisoning samples collected from local health bureaus were examined for Staphylococcus aureus. In addition, the enterotoxins produced by the isolates were determined using reversed passive latex agglutination (SET-RPLA). S. aureus was found in 16% (32/196) of food samples from markets and in 32% (54/169) of food poisoning samples. Furthermore, the most frequently found staphylococcal enterotoxin was type A which was detectecd in 50% (9/18) of the isolates from market food and in 81% (34/42) of the isolates from food poisoning samples, Enterotoxin A as low as 5 ng/g could be detected in rice and dairy products, and the recovery was better if SEA was present in foods at a concentration between 10-40 ng/g.

Key words: SET-RPLA, Staphylococcal enterotoxins, Staphylococcus aureus, Food poisoning.