Competative Exclusion in Sprouts

Byknocking out certain Salmonella genes, ARS food safety

researchers may discover genes are crucial tothis microbe’s ability to attack foods

AmyO. Charkowski

FoodSafety and Health Research Unit, Albany, CA

September 18, 2000

Theresearch, which is being conducted with the sprouted seeds of broccoli, radish,alfalfa, and mung bean, could lead to new and more effective tactics to thwartSalmonella not only in sprouts, but in other fresh produce-and perhaps even inmeats and poultry-as well. The ARS investigation into the key Salmonella genesmay be unique. So far, the experiments in which a gene or genes have beenknocked out of lab strains of the pathogen have yielded a Salmonella that isonly one-tenth as effective in colonizing fresh sprouts. Now scientists need todetermine which of the 4,000 to 5,000 Salmonella genes are missing or disabledin that strain. The researchers expect that help in answering this question willcome from scientists elsewhere who are collaborating in an international effortto determine the makeup and function of all Salmonella genes. Besides addingcolor, taste, and texture to salads, sandwiches, soups, and other dishes,sprouts provide protein, fiber, and antioxidants such as vitamin C.