The in vitro antimicrobial activities of phage STP4-a and its stability in simulated environments for different time intervals. (A) In vitro antimicrobial activity for a single strain, Salmonella Typhimurium ATCC 14028. (B) In vitro antimicrobial activity for 6 Salmonella strains. (C) The stability of phage STP4-a in simulated environments. Borders with blue color represented titers of phage in 12 mL simulated digestion preparations (4 mL simulated saliva and 8 mL simulated gastric juice, abbr. “SA + GA”) for 0, 1 h; Borders with red color represented titers of phage 8 mL simulated gastric juice (abbr. “GA”) for 0, 1, 2 h. Borders with green color represented titers of phage 12 mL simulated intestinal fluid (abbr. “IN”) for 0, 3 h.