Bacteriophage control of Salmonella Typhimurium in milk

This study was designed to evaluate the effect of bacteriophage P22 on the inhibition of growth of Salmonella Typhimurium. The P22 belongs to Podoviridae family consisting of a hexagonal head and short tail. The inhibitory effect of phage in milk was noticeable at the early storage period, showing more than 3 log reduction at 4 h and day 3. The pH values of milk treated with P22 were significantly decreased from 6.7 to 6.3 after 24 h incubation at 37 °C, while no significant changes in pH values were observed for the control and bacteriophage treatment throughout the storage at 4 °C for 12 days. The slight color changes were observed in the control and bacteriophage treatment throughout the storage at 4 °C for 12 days and 37 °C for 24 h. These results provide useful information for enhancing microbiological safety and quality of milk and designing effective bacteriophage-based control in food system.