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

Background and Aims: 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. Materials and Methods: 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: 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). Conclusions: 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.