Production of Staphylcoccal Enterotoxin A and Thermonuclease in Cream Pies

The change in pH, growth of mesophilic bacteria and growth, thermonuclease (TNase) and enterotoxin A (SEA) production by Staphylococcus aureus in artificially inoculated cream pies were investigated. The mesophilic count varied from 10⁴ CFU/g at 20°C to 4.0 × 10⁷ CFU/g at 37°C after 12 h of incubation and from 2 × 10⁶ CFU/g at 20°C to 7 × 10⁸ CFU/g at 37°C after 35 h of incubation. The S. aureus count varied from <10 ² at 20°C to 1.6 × 10⁴ CFU/g at 37°C after 12 h of incubation and from 8 × 10² at 20°C to 5.4 × 10⁶ at 37°C after 35 h of incubation. TNase was detectable after incubation for: 35 h at 20°C (2.9 ng/g), 12 h at 30°C (9.4 ng/g), and 12 h at 37°C (72 ng/g). SEA was detectable after incubation for: 35 h at 20°C (3.9 ng/g), 18 h at 25°C (3.9 ng/g) and 14 h at 30°C (4.8 ng/g).