Application of a broad range lytic phage LPST94 for biological control of salmonella in foods

Islam, Md. Sharifull; Zhou, Yang; Liang, Lu; Nime, Ishatur; Yan, Ting; Willias, Stephan P.; Mia, Md. Zakaria; Bei, Weicheng; Connerton, Ian F.; Fischetti, Vincent A.; Li, Jinquan

Abstract

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Salmonella, one of the most common food-borne pathogens, is a significant public health and economic burden worldwide. Lytic phages are viable alternatives to conventional technologies for pathogen biocontrol in food products. In this study, 40 Salmonella phages were isolated from environmentally sourced water samples. We characterized the lytic range against Salmonella and among all isolates, phage LPST94 showed the broadest lytic spectrum and the highest lytic activity. Electron microscopy and genome sequencing indicated that LPST94 belongs to the Ackermannviridae family. Further studies showed this phage is robust, tolerating a wide range of pH (4–12) and temperature (30–60◦C) over 60 min. The efficacy of phage LPST94 as a biological control agent was evaluated in various food products (milk, apple juice, chicken breast, and lettuce) inoculated with non-typhoidal Salmonella species at different temperatures. Interestingly, the anti-Salmonella efficacy of phage LPST94 was greater at 4◦C than 25◦C, although the efficacy varied between different food models. Adding phage LPST94 to Salmonella inoculated milk decreased the Salmonella count by 3 log10 CFU/mL at 4◦C and 0.84 to 2.56 log10 CFU/mL at 25◦C using an MOI of 1000 and 10000, respectively. In apple juice, chicken breast, and lettuce, the Salmonella count was decreased by 3 log10 CFU/mL at both 4◦C and 25◦C after applying phage LPST94 at an MOI of 1000 and 10,000, within a timescale of 48 h. The findings demonstrated that phage LPST94 is a promising candidate for biological control agents against pathogenic Salmonella and has the potential to be applied across different food matrices.

Citation

Islam, M. S., Zhou, Y., Liang, L., Nime, I., Yan, T., Willias, S. P., …Li, J. (2020). Application of a broad range lytic phage LPST94 for biological control of salmonella in foods. Microorganisms, 8(2), Article 247. https://doi.org/10.3390/microorganisms8020247

• Journal Article Type: Article
• Acceptance Date: Feb 11, 2020
• Online Publication Date: Feb 13, 2020
• Publication Date: Feb 13, 2020
• Deposit Date: Feb 12, 2020
• Publicly Available Date: Feb 13, 2020
• Journal: Microorganisms
• Electronic ISSN: 2076-2607
• Publisher: MDPI
• Peer Reviewed: Peer Reviewed
• Volume: 8
• Issue: 2
• Article Number: 247
• DOI: https://doi.org/10.3390/microorganisms8020247
• Keywords: phage; LPST94; Salmonella; characterization; biological control
• Public URL: https://nottingham-repository.worktribe.com/output/3952040
• Publisher URL: https://www.mdpi.com/2076-2607/8/2/247