Development of a peroxide biodetector for a direct detection of biofilms produced by catalase-positive bacteria on food-contact surfaces

Detection of biofilms on food-contact surfaces is essential for establishing sanitization procedures and avoiding microbial contamination of food products. The objective of our study was to develop a peroxide biodetector, to detect and reveal the presence of biofilms. A positive reaction was observed when biodetector bubbles were formed on stainless steel and polypropylene surfaces. A range of microorganisms able to form biofilms was evaluated. Catalase-positive bacteria: Staphylococcus aureus, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella enterica ser. Typhimurium and Cronobacter sakazakii were employed as well as the catalase-negative bacterium: Lactobacillus brevis. With the exception of C. sakazakii, all catalase-positive foodborne pathogens forming the biofilms showed a positive detection by the biodetector, being 104 CFU cm−2 the minimum microbial load detected. The strongest positive reaction was for P. aeruginosa. Results demonstrated the potential of this biodetector to detect biofilms, particularly when used as a tool in the food industry.