Characterization of SP-T1 Phage for Potential Biological Control of Salmonella Enteritidis

Abstract

Objectives: Salmonella Enteritidis is a pathogen that causes gastroenteritis and septicemia in humans and animals, causing worldwide health implications. This pathogen often causes fatal foodborne diseases in humans and animals. In recent years, new treatment strategies for bacterial infections have been studied. Bacteriophages might be used as an alternative strategy for battling against bacterial diseases. Methods: A novel SP-T1 phage was isolated, and its lytic activity against Salmonella Enteritidis strains and other enteric bacterial species was evaluated. In addition to its kinetic and genetic characteristics, it is in vivo cytotoxicity and ability to inhibit the development of biofilms were investigated. Results: The gene sequence of the major capsid protein confirmed that the SP-T1 phage belonged to the family Siphoviridae. There was no evidence that phage had a lytic effect on bacteria other than the type of Salmonella used in this investigation. The phage exhibited a short latent period of 15 to 20 min and a burst size of 10 plaque forming unit per infected cell. The phage was resistant to temperatures between 15 and 37 °C and pH levels between 5 and 11. The SP-T1 phage exhibited no adverse effects on EPC cell culture and reduced biofilm formation. Conclusions: Because of its short latent period, appropriate burst size, ability to inhibit biofilm formation, and sensitivity to various temperatures and pH levels, the phage found in this study would be an excellent candidate for phage therapy. These findings are beneficial for improving the microbiological safety and quality of food and creating efficient bacteriophage-based regulation in the food chain. J Microbiol Infect Dis 2023; 12(4):38-46.