Modelling the growth boundaries of Staphylococcus aureus: Effect of temperature, pH and water activity

Dynamics of staphylococcal enterotoxin production in model experiments simulating the fresh cheese environment

“…Optimum enterotoxin production occurs at a pH of 6-7 and the minimum pH suitable is about 4.8. At temperatures below 8 °C, the growth of S. aureus was inhibited, with no growth observed at 7.5 °C and at 8 °C, growth only occurred with optimum levels of pH and a w (Valero et al 2009). Staphylococcal counts should reach approximately 10 6 cfu·g -1 to be associated with enterotoxin production (Necidova et al 2009).…”

CommercialCarlinae radixherbal drug: Botanical identity, chemical composition and antimicrobial properties

“…This could be explained by its higher acidity (S. aureus growth is optimal at neutral pH (Valero et al, 2009), combined with the most probably somewhat different chemical composition compared to the other two extracts in water or wine (Table 3). However, vinegar itself had no activity on bacterial growth in these tests.…”

The formation ofStaphylococcus aureusenterotoxin in food environments and advances in risk assessment

“…15,94 These products are highly complex matrices compared with broth, with respect to, e.g., microbial content, salt, pH, nutrient availability, oxygen availability and temperature. 95 Generally, growth of S. aureus is necessary for enterotoxin production, although enterotoxin production does not always accompany growth, and in a few cases toxin production has been observed in non-replicating cell cultures, most recently by Wallin-Carlquist et al 8 in ham products. [96][97][98] Studies have been performed to identify key parameters that prevent or stimulate enterotoxin production in laboratory media and in diverse food products, and a multifaceted network of environmental and genetic factors seems to regulate enterotoxin production.…”

“…112,113 Available kinetic tertiary models can be used to predict growth and lag time based on various input values, for example, temperature, pH, water activity, nitrite concentration and aerobic/anaerobic conditions (PMP) (ComBase Predictor) and temperature in various types of meat (THERM). 114 An alternative approach is to describe the boundary between growth and no growth, 95 or survival/death, 115 the time before growth, 116 or the probability of growth, as a function of environmental parameters. Such models can be useful in the design of food processes to prevent growth and enterotoxin production.…”