Collaborative study on the precision of the enumeration of Staphylococcus aureus in food.

In order to compare the precision of the enumeration of Staphylococcus aureus in food with egg yolk tellurite glycine pyruvate agar (ETGP-agar) and with rabbit plasma fibrinogen agar (RPF-agar), a collaborative study was carried out in which 23 laboratories participated. In this study each laboratory examined an identical series of 10 samples of ice cream, artificially contaminated with S. aureus and other Gram-positive cocci at roughly 10(4) per ml.

Growth and enterotoxin production of Staphylococcus aureus in shrimp.

Strains of Staphylococcus aureus isolated from shrimp were examined for phage pattern and enterotoxin production; 63% of the strains isolated from North Sea shrimp were typable with the International and additional set of phages, as were 38% of the strains isolated from South-East Asian shrimp. Staphylococcal enterotoxin(s) (SE) were produced by 48% and 35% of strains isolated from North Sea and South-East Asian shrimp respectively. Growth and enterotoxin production by S.

Collaborative study on the isolation of salmonella from artificially contaminated milk powder.

The suitability of artificially contaminated milk powder as a substrate for salmonella reference samples and its stability under different storage conditions were studied. The need for a reconstitution step in the standard isolation method for salmonellas from milk powders was also investigated. When milk powder was examined in this way with a reconstitution step, differences in laboratory methods and/or storage times had no significant effect on the results after storage at 4 degrees C.

Serum antibodies to enterotoxins produced by Staphylococcus aureus with special reference to enterotoxin F and toxic shock syndrome.

The presence of antibodies to staphylococcal enterotoxins (enterotoxins A through F) in sera of healthy subjects (n = 567) and in sera of patients with toxic shock syndrome (n = 20) was determined. Furthermore, production of enterotoxins by Staphylococcus aureus isolated from humans was investigated. In 46, 86, 78, 41, 20, and 91% of the sera of healthy subjects, antibodies were found against enterotoxins A, B, C, D, E, and F, respectively.

Extraction of Staphylococcal Enterotoxins (SE) From Minced Meat and Subsequent Detection of SE with Enzyme-Linked Immunosorbent Assay (ELISA).

ELISA (enzyme-linked immunosorbent assay) was employed to demonstrate staphylococcal enterotoxins A, B, C and E (SEA, SEB, SEC and SEE) in minced meat (50% beef/50% pork). For unheated minced meat, extraction of the sample with an equal amount of distilled water at pH 4.5 and a subsequent concentration (10-fold) of the extract, readjusted to pH 7.