Effect of Food Residues in Biofilm Formation on Stainless Steel and Polystyrene Surfaces by Salmonella enterica Strains Isolated from Poultry Houses.

spp. is a major food-borne pathogen around the world. The ability of to produce biofilm is one of the main obstacles in reducing the prevalence of these bacteria in the food chain. Most of biofilm studies found in the literature used laboratory growth media. However, in the food chain, food residues are the principal source of nutrients of . In this study, the biofilm formation, morphotype, and motility of 13 strains belonging to three different subspecies and isolated from poultry houses was evaluated. To simulate food chain conditions, four different growth media (Tryptic Soy Broth at 1/20 dilution, milk at 1/20 dilution, tomato juice, and chicken meat juice), two different surfaces (stainless steel and polystyrene) and two temperatures (6 °C and 22 °C) were used to evaluate the biofilm formation. The morphotype, motility, and biofilm formation of was temperature-dependent. Biofilm formation was significantly higher with 1/20 Tryptic Soy Broth in all the surfaces and temperatures tested, in comparison with the other growth media. The laboratory growth medium 1/20 Tryptic Soy Broth enhanced biofilm formation in . This could explain the great differences in biofilm formation found between this growth medium and food residues. However, strains were able to produce biofilm on the presence of food residues in all the conditions tested. Therefore, the strain can use food residues to produce biofilm on common surfaces of the food chain. More studies combining more strains and food residues are necessary to fully understand the mechanism used by to produce biofilm on the presence of these sources of nutrients.