Use of Real-Time PCR for the reliable detection and quantification of Staphylococcus aureus in traditional fermented foods.

Staphylococcus aureus is a leading causative agent of gastroenteritis resulting from consumption of contaminated food. Its presence has been observed in many foods produced following traditional procedures, thus representing a concrete threat for the consumers. Recently, Real-Time PCR has been demonstrated to be an innovative, rapid and sensitive method for direct detection and quantification of several food-borne bacteria. The aim of this study was to develop a Real-Time PCR assay to evaluate the occurrence of S. aureus in traditional foods (cheeses and salami) produced in the Lessini Mountains (Verona, Italy) at eight small-scale facilities. Food sample processing, enrichment time, primer sequences and amplification conditions were optimised to obtain a low detection limit of the assay. A high percentage of samples contained S. aureus at a level ranging from 103 to 105 cell/ 25 g. These data emphasizes the necessity of controlling hygienic conditions of productions to assure the safety of traditional foods.