Investigate importance of Salmonella genes.By knocking out certain Salmonella genes, USDA/ARS researchers (Food Safety and Health Research Unit, Albany, CA) may discover which genes are crucial to this microbe's ability to attack foods. The research, which is being conducted with the sprouted seeds of broccoli, radish radish, herbaceous plant (Raphanus sativus) belonging to the family Cruciferae (mustard family), with an edible, pungent root sliced in salads or used as a relish. , alfalfa alfalfa (ălfăl`fə) or lucern (l  sûn`), perennial leguminous plant (Medicago sativa and mung bean mung bean n. 1. An Asian plant (Vigna radiata) in the pea family, widely cultivated for its edible seeds and pods. It is the chief source of bean sprouts. 2. The seeds or pods of this plant. , could lead to new and more effective tactics for thwarting Salmonella not only in sprouts, but in other fresh produce, and perhaps even in meat and poultry. The ARS investigation into the key Salmonella genes may be novel. So far, the experiments, in which genes have been knocked out of lab strains of the pathogen, have yielded a Salmonella that is only 10% as effective in colonizing fresh sprouts. Now scientists need to determine which of the 4000 to 5000 Salmonella genes are missing or disabled in that strain. The researchers expect that help in answering that question will come from scientists elsewhere who are collaborating in an international effort to determine the makeup and function of all Salmonella genes. Besides adding color, taste and texture to salads, sandwiches, soups and other dishes, sprouts provide protein, fiber and antioxidants Antioxidants Substances that reduce the damage of the highly reactive free radicals that are the byproducts of the cells. Mentioned in: Aging, Nutritional Supplements antioxidants, n. , such as vitamin C vitamin C or ascorbic acid Water-soluble organic compound important in animal metabolism. Most animals produce it in their bodies, but humans, other primates, and guinea pigs need it in the diet to prevent scurvy. . We've learned that treating alfalfa seeds and sprouts with a combination of irradiation and chlorine effectively safeguards them against contamination by E. coli E. coli: see Escherichia coli. E. coli in full Escherichia coli Species of bacterium that inhabits the stomach and intestines. E. coli can be transmitted by water, milk, food, or flies and other insects. O157:H7 and Salmonella. In tests, a treatment of irradiation and a chlorine solution not only killed both organisms, but also extended the shelf life of sprouts from about five days to more than a week. The finding is good news for sprout growers. Since 1995, raw alfalfa sprouts have been recognized as a source of foodborne illness in the United States, with several outbreaks of both E. coli O157:H7 and Salmonella occurring. Since sprouts can't withstand abrasive physical washing because of their fragility, cleaning the seed has become the primary focus of safety efforts. In the tests, the scientists used the irradiation dose approved for irradiating meat. The best way to eliminate pathogens would be a combination of irradiation and sanitation treatments. This is because sprouts can be contaminated contaminated, v 1. made radioactive by the addition of small quantities of radioactive material. 2. made contaminated by adding infective or radiographic materials. 3. an infective surface or object. internally, which would prevent a surface disinfectant alone from working effectively. Further information. Amy Charkowski; phone: 510-559-5647; fax: 510-559-5777; email: amy@pw.usda.gov. |
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