Biofilm Forming Ability of Broiler Chicken Meat Associated Salmonella spp. on Food Contact Surfaces

Biofilms in the meat industry pose a significant impact on public health as many foodborne pathogens can form biofilms on equipment and utensils in meat processing plants. Biofilms formed on contact surfaces could be a continuous source of contaminants to food that come in contact with them. In the present study biofilm-forming ability of different Salmonella spp. isolated from broiler chicken meat from Sri Lanka was quantified, the presence of biofilm-related genes was investigated, and comparative evaluation on the biofilm formation on plastic, stainless steel, and glass surfaces was performed. It was revealed that the biofilm formation increased as a response to the nutrient stress. Quantification of biofilm formation by the microtitre plate method showed 7 strong (30.4%), 11 moderate (47.8%), and 5 weak (21.7%) biofilm formers at low nutrient media (TSB diluted 1:100), whereas there were only 4 moderate biofilm formers and 19 weak biofilm formers found in the undiluted TSB medium. All biofilm formers exhibited the presence of both adrA and gcpA regulatory genes. Investigation on the ability of biofilm formation on glass, stainless steel, and plastic at time points of 48, 96, 144, 192, and 240 hrs post incubation with the contamination of 106 CFU/cm2 revealed a significant (p≤0.05) variation among Salmonella isolates. All the isolates illustrated the highest ability to form biofilms on plastic, whereas that was minimum on stainless steel.