2.3. Description of Strains and Activation

S. enterica serotype Typhimurium (ATCC® 14028™), S. enterica serotype Poona (ATCC® BAA-1673™), L. monocytogenes (ATCC® 13932™), and L. monocytogenes (ATCC® 19112™) were used for this study. Strains were kept under 4°C and activated using 9 ml of Tryptic Soy Broth with yeast extract (TSB-YE, Neogen, Culture Media, MI), which were incubated at 37°C for 24 hours. A biconvex drop from each strain was streaked onto the surface of Tryptic Soy Agar (TSA, Neogen Culture Media, MI) plates, using a sterile loop to isolate colonies of the respective strains. To conclude with the activation, one single isolated colony was placed in TSB-YE to enrich the pure colonies of each of the four strains. Finally, a cocktail of the strains was prepared by mixing equal volumes of each culture.