Isolation and characterization of a novel phage ST BD for the biological control of Salmonella in dairy food matrices

• Published in: Food control Vol. 168; p. 110848
• Main Authors: Chahar, Madhvi, Rana, Anuj, Gupta, Vinay Kumar, Singh, Anu, Singh, Namita
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2025
• Subjects: Antibacterial; Bacteriophage; Dairy food; Food safety; Salmonella; Whole genome; Salmonella; Whole genome; Food safety; Antibacterial; Dairy food; Bacteriophage
• ISSN: 0956-7135
• DOI: 10.1016/j.foodcont.2024.110848

Bacteriophages are intended as a new approach to control foodborne pathogens in food matrices. In the present study, a novel phage ST BD specific for Salmonella was isolated from buffalo dung samples. The efficiency of plating and scanning electron microscopy analysis revealed the high lytic activity of phage ST BD against Salmonella Typhimurium with a huge burst size (396 PFU/cell) and a short latent period (40 min). Potential phage ST BD showed high stability at 4 °C storage temperature with only 10% reduction in phage activity. Transmission electron microscopy micrographs revealed that phage ST BD belongs to the Myoviridae family. The whole genome sequencing data revealed that phage ST BD was inclined towards completely lytic and showed absence of toxins, antibiotic resistance and virulence genes. Comparative genome analysis suggested that phage ST BD constitutes a novel member of the genus Duplodnaviria and family Myoviridae. Artificially contaminated dairy food matrices such as milk, cheese and paneer treated with high MOI of lytic phage ST BD demonstrated extensive inhibition of Salmonella Typhimurium growth (p ≤ 0.05), resulting in 5.4, 4.6 and 4.1 log CFU/mL reduction, respectively, after 1 day as compared to untreated control and a remarkable reduction was observed after 6 days of phage treatment with subsequent 7.0, 6.9 and 5.6 log CFU/mL of Salmonella growth reduction, respectively, at a storage temperature of 4 °C. The identified novel phage provides a basis for the future development of potential biocontrol candidates against Salmonella in a wide variety of food matrices. •ST BD phage treatment controlled the growth of Salmonella in dairy food products.•ST BD phage genome displayed absence of toxins, resistance and virulence genes.•ST BD phage revealed a wide host range against Salmonella strains.•ST BD phage revealed high burst size and a short latent period.