Phage Biocontrol Applications in Food Production and Processing

Abstract

Bacteriophages, or phages, are one of the most -if not the most -ubiquitous organisms on Earth. Interest in various practical applications of bacteriophages has been gaining momentum recently, with perhaps the most attention (and most regulatory approvals) focused on their use to improve food safety. This approach, termed "phage biocontrol" or "bacteriophage biocontrol," includes both pre-and post-harvest application of phages as well as decontamination of the food contact surfaces in food processing facilities. This review focuses on post-harvest applications of phage biocontrol, currently the most commonly used type of phage mediation. We also briefly describe various commercially available phage preparations and discuss the challenges still facing this novel yet promising approach. Phages are Ancient and Abundant in NatureBacteriophages are the viruses that infect bacteria. They were discovered in 1917 by Félix d'Hérelle in 1917 (Salmond andFineran, 2015;Sulakvelidze et al., 2001), who also coined the term "bacteriophage," derived from "bacteria" and the Greek φαγεῖν (phagein) meaning "to eat" or "to devour" bacteria. Numerous studies, including recent metagenomic surveys, suggest that phages are (i) arguably the oldest microorganisms on this planet that likely originated approximately 3 billion years ago (Brüssow, 2007), and (ii) likely the most ubiquitous organisms on Earth, abundant in all life-supporting environments including all natural untreated foods. To give a few examples: (1) There are an estimated 1.5 × 10 8 phage particles per gram of agricultural soil (Ashelford et al., 2003;Williamson et al., 2003); (2) There are an estimated 7 to 15 × 10 6 phages per mL in fresh water lakes (Mohiuddin and Schellhorn, 2015) and 10 6 to 10 9 particles per mL in sea water (Bergh et al., 1989); (3) Bacteriophages are likely present in 100% of fresh unprocessed foods and have been isolated from various food products such as beef, pork, chicken, fresh produce, dairy, and fermented foods (Aw et al., 2016;Park et al., 2011;Zhang et al., 2014); (4) Humans are constantly exposed to phages in their daily lives as highly diverse and abundant phage populations are present on various Curr. Issues Mol. Biol. (2021) 40: 267-302. caister.com/cimb caister.com/cimb 267 Curr. Issues Mol. Biol. Vol. 40

Deploying Viruses against Phytobacteria: Potential Use of Phage Cocktails as a Multifaceted Approach to Combat Resistant Bacterial Plant Pathogens

“…Similarly, a cocktail of phages is widely used to control antibiotic-resistant Staphylococcus aureus and P. aeruginosa in the treatment of chronic otitis infections [64]. In the food industry, phage cocktails are used as an innovative therapeutic approach to treat various foodborne pathogens, such as Salmonella entrica, Listeria monocytogenes, Escherichia coli, Shigellasonnei, and Campylobacter jejuni for pre-and post-harvesting food protection and processing to save millions of lives from food poison-mediated diseases [71][72][73][74]. P1 cocktail consisting of six phage isolations may kill 98% of R. solanacearum through direct application via soil drenching for the biocontrol of bacterial wilt disease of potato and tomato [61,75].…”

Investigation of phage and molasses interactions for the biocontrol ofE. coliO157:H7

“…Phage therapy applications can be used in pre-and post-harvest processes of food as well as food contact surfaces. Phage therapy has crucial advantages against chemical disinfectants used in the food industry applications such as being specific to target pathogen, abundance in nature, having minimal or none harmful effect on natural microflora and minimal or none sensory effect on food (Vikram et al 2020). Combination of phage and molasses can be used to reduce pathogenic bacteria in the food industry, but more comprehensive analyzes are required for optimizing the application.…”

Phages for Africa: The Potential Benefit and Challenges of Phage Therapy for the Livestock Sector in Sub-Saharan Africa

“…The efficacy of bacteriophages as antimicrobials has fostered the approval and commercialization of several products intended for the reduction of different pathogenic bacterial species [83]. Examples of some phage-related products include SalmoFree and SalmoFresh™, both containing Salmonella enterica phages [82,84], ListShield™ designed with Listeria monocytogenes phages [85], as well as phage-derived enzymes such as Lysins, integrases, and excisionases, have received considerable attention as potential antibacterial agents [86]. Phage and phage related products have advantages over antibiotics in many ways; e.g., some applications may require only a single dose since phages can self-amplify.…”