A virulent bacteriophage, specific to pathogenic bacteria Salmonella
Typhimurium ATCC 13311, was isolated from water collected from a swine lagoon. The
bacteriophage, designated ST1, had a broad host range and was stable at the temperature
up to 60°C for 3 min and over a wide pH range (5 to 11). Its genome was double stranded
DNA. Transmission electron microscopy revealed that the bacteriophage had an isometric
head of 70 nm in diameter and a long noncontractile tail of 150 nm long and 7 nm wide.
It was classified as a member of the family Siphoviridae. Bacteriophage ST1 was stable
in soybean milk but not in guava juice and orange juice. When applied together with S.
Typhimurium (106 CFU/ml) in soybean milk, the bacteriophage reduced the bacterial cells
with a dose dependent pattern. The application of more bacteriophage (108 PFU/ml) was
more effective than lower doses (106 and 107 PFU/ml). This study suggests that bacteriophage
ST1 has a potential for being use as a biocontrol agent against S. Typhimurium in
beverages.