Equipment Contamination - prevention & control, Microscopy, Electron, Scanning, Polypropylenes, Humans, Biofilms - growth & development, Salmonella - physiology, Colony Count, Microbial, Microbial Viability, Food Microbiology, Bacterial Adhesion, Food Contamination - prevention & control, Salmonella - ultrastructure, Salmonella - growth & development