Extended staphylococcal enterotoxin D expression in ham products.

Area of Science:

• Food Microbiology
• Food Safety
• Bacterial Toxinology

Background:

• Staphylococcal enterotoxin D (SED) is a common cause of staphylococcal food poisoning (SFP).
• Understanding SED production in different food matrices is crucial for food safety.
• Ham products are susceptible to Staphylococcus aureus contamination.

Purpose of the Study:

• To investigate the expression and production of SED in various ham products.
• To compare SED levels relative to bacterial growth in different ham types.
• To determine if ham products can accumulate SED to levels causing SFP.

Main Methods:

• Incubation of boiled, smoked, and dry-cured Serrano ham at room temperature for seven days.
• Monitoring Staphylococcus aureus growth and SED expression/production.
• Cultivation of S. aureus in broth under optimal conditions as a reference.
• Quantification of SED per colony-forming unit (CFU).

Main Results:

• Continuous sed expression was observed in boiled and smoked ham, with a secondary increase after five days.
• Smoked ham showed significantly lower SED per CFU compared to boiled ham.
• SED was detected in Serrano ham after five days, despite poor bacterial growth.
• All three ham products contained sufficient SED to potentially cause SFP after five days of incubation.
• SED production was not always directly correlated with bacterial growth levels.

Conclusions:

• SED production varies significantly across different ham products.
• The potential for SFP exists in various ham products due to SED accumulation.
• Bacterial growth and toxin production can be uncoupled, highlighting complex food safety risks.