Growth of Staphylococcus aureus and enterotoxin production in fresh egg pasta

This study investigated the growth of enterotoxin-producing Staphylococcus aureus and time–temperature combinations necessary for enterotoxin production in artificially and naturally contaminated fresh egg pasta. Egg pasta (35 ± 1 g) inoculated with three strains of enterotoxin-producing S. aureus at two different concentrations (103 CFU/g and 10 CFU/g) were incubated at 20 °C, 30 °C and 37 °C for 34 h. Industrial samples were S. aureus was naturally present at a concentration of 2.5 x 102 CFU/g were incubated under the same conditions. Enterotoxin was produced in all samples inoculated with the three strains of S. aureus incubated at 20 °C for 24 h or 30 °C for 10 h. No enterotoxin was produced in the naturally contaminated samples, even if the S. aureus concentration reached 106–107 CFU/g by the end of the experiment (34 h) indicating that the Staphylococci isolated in the production line were not enterotoxin-producing strains. Practical application: This research focused on the growth and enterotoxin production of Staphylococcus aureus naturally present on fresh egg pasta produced in an industrial line or artificially inoculated with three different strains of this bacterium. Our results confirmed that the staphylococci, naturally contaminating the fresh egg pasta during the production, were not enterotoxin-producing. However, the results obtained using enterotoxin producing strains show that this kind of product can support the development of theses bacteria and enterotoxin production. Therefore, these results should be useful to fresh pasta manufacturers and aid them in setting up their control measures in the Hazard Analysis and Critical Control Point in order to manage the microbial safety of the fresh egg pasta products.