The biologically pure vB_Eco_SF18 bacteriophage strain is capable of controlling Escherichia coli in pork.

Abstract

The biologically pure bacteriophage strain vB_Eco_SF18 was isolated from the feces of healthy wild boars in Bac Ninh, Vietnam. The strain has a broad host range against Escherichia coli strains, including non-pathogenic strains (E. coli ATCC 25922, MG1655, K12, BL21) and strains pathogenic to humans (E. coli O151, E. coli O177). The bacteriophage has a nearly spherical, polyhedral head, a long, non-contractile tail, a head diameter of approximately 57.3 nm, a tail length of approximately 140.6 nm, a double-stranded DNA genome of 43,931 bp, belongs to the genus Dhillonvirus, and does not contain virulence genes. The strain achieved approximately 100% lysis of E. coli after 7 hours of culture at an MOI infection rate of 0.0001, had a short latent period, a bloom size of approximately 138 PFU per lysed cell, maintained activity up to 60°C and within a pH range of 6.0-8.0. When applied to pork cuts and minced pork contaminated with E. coli, the vB_Eco_SF18 strain rapidly reduced bacterial density at both 4°C and 30°C after 6 hours, demonstrating potential for application in E. coli control.E. coli causes disease and improves food safety.