MODERN AND MODIFIED TECHNIQUES FOR STAPHYLOCOCCITOXL SASSAY

Abstract

Evaluation and standardization of different Staphylococcal enterotoxin assay techniques (Microslide double gel-diffusion, Electroimmunodiffusion, Reversed passive latex agglutination and Enzyme linked im.munosorbent assay) were carried out for standard reference enterotoxins A,B and D. Evaluation was achieved' by measuring and compairing the method sensitivity and confirmatory responces. The resulting standard curves and assay by these methods were reapplied on laboratory produced enterotoxins for further evaluation. Evaluation of the applicability of these methods for assay of reference enterotoxins types A,B and D seeded in milk, Domiati and Ras cheeses, were implemented. In addition, assay of enterotoxin A,B and D produced by S.aureus different strains inoculated in raw, pasteurized milk and Domiati, Gouda and Ras cheeses was studied using the different methods. The RPLA and ELISA methods showed the higher sensitlVIy than Microslide double gel-diffusion and Electroimmunodiffusion methods. Moreover, ELISA was found as the most sensitive and confirmatory method for detection of staphylococcal enterotoxins Based on the examination purpose, the most reliable mothods were: 1. ELISA (Sensitivity = I.0 ng/ml, 90 min. to get a results) , was ' the preferable method for very accurate, very fast, testing trace amount of SETs. 2. RPLA (Sensitivity= 1.25-1.5 ng/ml, 24 h. to get a result). was the preferable method for identifying the type of SETs and estimated concentration.