<i>Salmonella</i> Biofilm Formation under Fluidic Shear Stress on Different Surface Materials

Abstract

This study characterized biofilm formation of various Salmonella strains on common processing plant surface materials (stainless steel, concrete, rubber, polyethylene) under static and fluidic shear stress conditions. Surface-coupons were immersed in well-plates containing 1 mL of Salmonella (6 log CFU/mL) and incubated aerobically for 48 h at 37 °C in static or shear stress conditions. Biofilm density was determined using crystal violet assay, and biofilm cells were enumerated by plating on tryptic soy agar plates. Biofilms were visualized using scanning electron microscopy. Data were analyzed by SAS 9.4 at a significance level of 0.05. A surface–incubation condition interaction was observed for biofilm density (p 600 was higher under shear stress than static incubation; whereas, on polyethylene, the OD600 was higher under static condition. Enumeration revealed surface–incubation condition (p = 0.024) and surface–strain (p p S. Kentucky on polyethylene had the highest number of cells (7.80 log/coupon) compared to all other strain–surface combinations (p Salmonella biofilm formation is influenced by serotype, surface, and fluidic shear stress.

Keywords

• <i>Salmonella</i>
• biofilm
• crystal violet
• shear stress
• poultry processing