Anti-biofilm potential of peptides against foodborne pathogens

Abstract

Background: Biofilm is defined as a community where bacterial cells encased in a matrix of extracellular polymeric substances adhere to each other and/or to a surface. In food industry, foodborne pathogens like Salmonella are capable of forming biofilms on open surfaces. We have shown anti-biofilm effects of ε-poly-lysine (PL) and milk serum protein (MSP) against various bacteria. In this study, peptides derived from egg was investigated for anti-biofilm effects on foodborne pathogens. Methods: Effects of several kinds of peptides, including 3 kinds of hydrolysates derived from egg, together with PL and MSP, on biofilm formation of 4 kinds of foodborne pathogens (Escherichia coli O157:H7, S. Typhimurium, Staphylococcus aureus and Listeria monocytogenes) were investigated on microtiter plates through biomass quantification with crystal violet staining. Results: Both 0.01% PL and 0.25% MSP significantly decrease biofilm formation of all the pathogens, while PL was more effective than MSP against gram-negative bacteria. All the hydrolysates showed considerable effect under high concentration (1%), among them hydrolysate 2 was more effective than the others since it inhibited biofilm formation of S.Typhimurium, even under concentration of 0.1%. Conclusion: The egg white hydrolysate contains some antibacterial peptides that could modulate biofilm formation of S.Typhimurium and other pathogens, which could be beneficial to develop new strategies to combat biofilm infections.