Biofilm Formation of Salmonella typhimurium on Stainless Steel in Red Meat Model and the Effect of Bacteriophage on Bacterial Biofilm

The application of bacteriophage to control and removal of bacterial biofilm is a novel method. The goal of this study was to investigate the effect of the Salmonella typhimurium bacteriophage against biofilm of a multidrug resistance (MDR) Salmonella formed on stainless steel in beef broth. One and 7 days old biofilm were grown at 15, 8 and 4 °C, on the stainless steel in beef broth and the effects of different bacteriophage concentrations (103, 105 and 107 PFU/mL) with two contact times (10 and 15 min) were assayed. Results showed that Salmonella can adhere to stainless steel and form biofilm in the beef broth which was significantly influenced by temperature. Higher biomass of biofilm was developed at 15, 4 and 8 °C, respectively. One-day-old is less dense (~1 logarithmic cycle) than 7-day-old biofilm. No significant difference (P>0.05) in biofilm reduction was observed in samples treated with different concentration as compared with control. Statistical differences were also not observed in the different contact time (10 and 15 min). These results indicated that there was no significant reduction in MDR Salmonella biofilm population developed on stainless steel in the beef broth after using the bacteriophage; it is needed to investigate some combination procedures or increase contact time to improve the biofilm removal activity of bacteriophage.