Temperature limits of growth, TNase and enterotoxin production of Staphylococcus aureus strains isolated from foods.

For 77 strains of Staphylococcus aureus freshly isolated from different foods, growth, enterotoxin and TNase production were determined in intervals of 1.5 degrees C +/- 0.5 degrees C by cultivating them in a temperature-gradient incubator between 5 and 50 degrees C for up to 7 days. All the strains were coagulase, DNase and lysostaphin positive but only 58% formed one or two enterotoxins type SEA, SEB or SEE. All strains grew within 7 days in brain heart infusion and had lower and upper temperature limits for growth and TNase production of between 6.5 and 12.5 degrees C, and 39.5 and 48.5 degrees C respectively. The lower and upper temperature limits for production of enterotoxins were between 14 and 38 degrees C, and between 35 and 44 degrees C respectively. Enterotoxin forming isolates either showed narrow (3 to 4 degrees C) or wide (10 to 20 degrees C) ranges of enterotoxin production, irrespective of their temperature range of growth and TNase production. None of the 12 specific physiological attributes used for differentiation could be correlated to toxin type or the temperature requirement of the toxin production. No correlation between the origin and the physiological characters could be detected.