Food-borne pathogens, health and role of dietary phytochemicals

Infectious diseases transmitted by food have become a major public health concern in recent years. In the USA alone, there are an estimated 6-33 million cases each year. The list of responsible agents continues to grow. In the past 20 years some dozen new pathogens that are primarily food-borne have been identified. Fruits and vegetables, often from the global food market, have been added to the traditional vehicles of food-borne illness; that is, undercooked meat, poultry, seafood, or unpasteurized milk. Such products are minimally processed and have fewer barriers to microbial growth such as salt, sugar or preservatives. The evolution of the epidemiology of food-borne illness requires a rethinking of traditional, though still valid, solutions for their prevention. Among various strategies to prevent food-borne pathogens, use of dietary phytochemicals is promising. The major obstacle in the use of dietary phytochemical is the consistency of phytochemicals in different foods due to their natural genetic variation. We have developed a novel tissue-culture-based selection strategy to isolate elite phenolic phytochemical-producing clonal lines of species belonging to the family Lamiaceae. Among several species we have targeted elite clonal lines of thyme (Thymus vulgaris) and oregano (Origanum vulgare) against Escherichia coli and Clostridium perfrigens in fresh and processed meats. We are also evaluating high phenolic profile-containing clonal lines of basil (Ocimum basilicum) to inhibit gastric ulcer-causing Helicobacter pylori. Other elite lines of the members of the family Lamiaceae, rosemary (Rosmarinus officinalis) and salvia (Salvia officinalis) also hold promise against a wide range of food pathogens such as Salmonella species in poultry products and Vibrio species in seafood.