Properties of Staphylococcus aureus strains from food processing staff

The food processing staff may act as a reservoir of virulent strains of Staphylococcus aureus and contribute to their transmission to foods. The aim of this study was to assess the occurrence and properties of S. aureus in cheese factory staff.

Throat and hand swabs collected from the staff of three different cheese factories were tested. The obtained isolates were characterized on the basis of detection of virulence factors, antimicrobial resistance testing, spa typing, and macrorestriction analysis.

S. aureus was detected in 58% of the hand swab samples (7/12) and in 47% (17/36) of the throat swab samples. No methicillin-resistant S. aureus was detected in the throat or on the hands of the food processing staff. Strains carrying genes responsible for the production of enterotoxins (58%) and/or toxic shock syndrome toxin (25%) were recovered from employees of all three premises. One throat swab isolate was positive for the gene encoding production of exfoliatin A. There was no clonal relationship between S. aureus strains isolated from the throat and hands, which suggests possible contamination of the employees' hands arising from the manufacturing environment.

Good compliance with hygiene guidelines (washing and disinfecting hands and the environment regularly, using gloves and masks, etc.) is a necessary tool for reducing the risk of S. aureus spread by the employees working in the food industry.