I’m a bit of a sceptic when it comes to the idea that “phage therapy” is going to save us when the antibiotics fail. There have been enough clinical trails now to show that this cannot be true, at least in simple terms. But that’s not to say that bacteriophages don’t have their uses in controlling bacteria. Topical treatment of wounds is one interesting area, and using phages to control bacterial contamination of foods is another area worth exploring.
This paper isolates two relatively broad-spectrum Salmonella phages and tests whether they are effective in reducing contamination of chicken meat, milk and vegetables. And the answer is … somewhat effective. Phage therapy/treatment is not a magic bullet and it’s never going to be. But “more work needs to be done to determine whether phages can be used to disinfect food products“.
Bio-Control of Salmonella Enteritidis in Foods Using Bacteriophages. (2015) Viruses, 7, 4836-4853
Two lytic phages, vB_SenM-PA13076 (PA13076) and vB_SenM-PC2184 (PC2184), were isolated from chicken sewage and characterized with host strains Salmonella Enteritidis (SE) ATCC13076 and CVCC2184, respectively. Transmission electron microscopy revealed that they belonged to the family Myoviridae. The lytic abilities of these two phages in liquid culture showed 104 multiplicity of infection (MOI) was the best in inhibiting bacteria, with PC2184 exhibiting more activity than PA13076. The two phages exhibited broad host range within the genus Salmonella. Phage PA13076 and PC2184 had a lytic effect on 222 (71.4%) and 298 (95.8%) of the 311 epidemic Salmonella isolates, respectively. We tested the effectiveness of phage PA13076 and PC2184 as well as a cocktail combination of both in three different foods (chicken breast, pasteurized whole milk and Chinese cabbage) contaminated with SE. Samples were spiked with 1 × 104 CFU individual SE or a mixture of strains (ATCC13076 and CVCC2184), then treated with 1 × 108 PFU individual phage or a two phage cocktail, and incubated at 4 °C or 25 °C for 5 h. In general, the inhibitory effect of phage and phage cocktail was better at 4 °C than that at 25 °C, whereas the opposite result was observed in Chinese cabbage, and phage cocktail was better than either single phage. A significant reduction in bacterial numbers (1.5–4 log CFU/sample, p < 0.05) was observed in all tested foods. The two phages on the three food samples were relatively stable, especially at 4 ºC, with the phages exhibiting the greatest stability in milk. Our research shows that our phages have potential effectiveness as a bio-control agent of Salmonella in foods.