Phage preparation for managing Salmonella in foods

Salmonellae continue to be one of the leading worldwide causes of foodborne bacterial diseases. They cause 1.2-1.4 million annual cases of salmonellosis in the USA, with associated costs estimated to be as high as $12.8 billion/year (in 1998 dollars). Despite continued and escalating efforts to curb diseases caused by foodborne bacterial pathogens, salmonellae continue to produce foodborne illness at an alarming and increasing rate. In this context, although the overall incidence of foodborne diseases has been declining in the United States, the 2010 report from the FoodNet indicated that the incidence of laboratory-confirmed Salmonella infections continued to increase by approximately 3%, causing 1.2 million U.S. illnesses in that year and being the most common cause of hospitalization and death tracked by the FoodNet. In fact, the incidence of Salmonella-elicited disease during 2010 was nearly 3-fold more than the 2010 national health objective target, and current outbreaks of salmonellosis continue to occur on a regular basis. Moreover, in a disturbing recent development, a Salmonella Typhimurium strain isolated from contaminated ground beef (which was implicated in a multistate outbreak during the fall of 2011) was found to be resistant to several commonly prescribed antibiotics. This is an alarming development because disease caused by such multidrug-resistant strains is associated with an increase in the risk of hospitalization or possible treatment failure in infected individuals. This finding, together with the continuing increase in the incidence of salmonellosis in the United States despite current efforts to curtail that disease, underscores the importance of developing novel intervention strategies and products capable of eliminating or significantly reducing Salmonella in various foods without promoting the emergence of antibiotic-resistant mutants. Any such products should be effective, cheap, safe, environmentally friendly, and easy to use - and there would also be potential advantages for products that target specific Salmonella serotypes; e.g., serotypes predominantly associated with human illness. We believe that a bacteriophage-based preparation/approach may be one such modality. With the partial support from the NIFA USDA Phase I grant, we developed a bacteriophage-based preparation (designated "SalmoFresh") lytic for Salmonella. During our preliminary studies, we found that SalmoFresh consistently and significantly reduced Salmonella levels in various poultry products by as much as 98%. The goals of our currently proposed Phase II project are to (i) obtain additional data concerning the efficacy of SalmoFresh treatment of various foods that are at high risk of Salmonella contamination, and (ii) obtain pertinent regulatory approvals that will enable us to make SalmoFresh available to the food industry and, thus, help to reduce foodborne contamination with Salmonella. We believe that SalmoFresh has the potential to help significantly reduce Salmonella contamination of various foods (including poultry products) and, therefore, to have a significant impact on improving food safety and public health.