Influence of temperature and surface kind on biofilm formation by Staphylococcus aureus from food-contact surfaces and sensitivity to sanitizers

This study aimed to assess the adhesion, detachment kinetic and biofilm formation of Staphylococcus aureus isolates from food services surfaces on stainless steel and polypropylene surfaces when cultivated in a vegetable-based broth at 7 and 28 °C, and the efficacy of peracetic acid (30 mg/L) and sodium hypochlorite (250 mg/L) in removing the bacterial cells from the matrix of the preformed biofilm. The isolates adhered over 4 Log cfu/cm2 regardless the surface kind and incubation temperature. Cell detachment was around 3 Log cfu/cm2 over the first six contacts with agar characterizing a high persistence of cells on the tested surfaces. Number of cells (5-7 Log cfu/cm2) needed for biofilm formation was noted at all experimental systems already after 3 days of incubation. A range of 2.0-3.3 and 1.5 to 2.1 Log cfu/cm2 was observed in the reduction of cells in biofilm matrix caused by peracetic acid and sodium hypochlorite, respectively. The isolates of S. aureus revealed high capability to adhere and form biofilm on the tested surfaces in both assayed incubation temperature.

► S. aureus from food-contact surfaces formed biofilm on stainless and polypropylene. ► Bacterial count indicated biofilm formation by S. aureus at 7 and 28 °C after 3 days. ► Sanitizers were not effective in totally remove the cells of the biofilm matrix.