S18: Bacteriophages for Improving Food Safety: Safety By Nature™

Lytic bacteriophages/phages (viruses that kill bacteria) are the oldest and most ubiquitous microorganisms on Earth.  Because of their potent, highly specific antibacterial activity, phages may provide an all natural, nontoxic, and effective means for significantly reducing or eliminating bacterial pathogens present in various foods or food processing facilities.  Several phage-based products have been recently introduced, including ListShield™ and Listex™ (both targeting Listeria monocytogenes) and EcoShield™ (targets Escherichia coli O157: H7), and several others are in various stages of regulatory approvals / development.  These products, when properly applied, reduce significantly the levels of their bacterial hosts contaminating various foods and/or various hard surfaces in food processing facilities and other food establishments.  For example, EcoShield treatment significantly reduced (p = <0.05) the concentration of viable E. coli O157:H7 in experimentally contaminated tomato, spinach, broccoli, and ground beef specimens.  The observed reductions ranged from 94% for the tomato specimens to 100% for spinach, and were typically 95-100% for ground beef.  Similarly, ListShield treatment reduced the concentration of L. monocytogenes by >100-fold in >15 different experimentally contaminated foods (including poultry and meat products, fruits and vegetables, and smoked salmon) and, in several cases, it completely eliminated the bacterium.  Neither of the currently marketed phage preparations altered the treated foods’ flavors, aromas, or appearances.  The presentation will review information about the effectiveness of bacteriophages in specific foods and food processing settings, and will discuss regulatory and safety issues concerning the use of bacteriophages in the food industry.