Detection of staphylococcal enterotoxins in foodstuffs of animal origin by ELISA method

Abstract

Many foods of animal origin represent an excellent substrate for growth of Staphylococcus aureus and production of staphylococcal enterotoxins (SE) . Contamination of food of animal origin (milk and meat) with enterotoxigenic strains of coagulase positive staphylococci during the production cycle can lead to production of SE and to the occurrence of foodborne intoxication, due to consumption of the contaminated final product. The objective assessment of potential microbiological risk requires an adequate control of food of animal origin for the presence of S. aureus and staphylococcal enterotoxin. To determine the number of coagulase positive staphylococci, the EN ISO 6888-1 method was applied. For determination of the presence of staphylococcal enterotoxin the ELISA kit Transia was used. Out of 15 investigated milk products, coagulase-positive staphylococci were determined in two cheese samples and two ice cream samples. Staphylococci strains ranged from 2.07±0.06 to 6.78±0.13 log10 cfu/g/ml. Out of ten tested meat samples, three samples contained coagulase positive staphylococci, ranging from 2.60±0.11 to 3.38±0.14 log10 cfu/g. The presence of staphylococcal enterotoxin was determinited in one ice cream sample only, in the quantity of 1.56 ng/ml. This sample contained 2.39±0.03 log10 cfu/g/ml S. auerus.