August 29, 2000

Food safety practices and programs must be based on sound science to effectively prevent or control the occurrence of microbial pathogens and their toxic metabolites in food and respond efficiently to foodborne disease outbreaks. The President’s Food Safety Initiative has provided increased funding for research and risk assessment activities intended to identify and to address priority research needs related to enhancing the microbiological safety of the food supply.

Five broad areas in research and three broad areas in risk assessment development have been identified in which significant knowledge gaps or the lack of appropriate scientific data, methods, or models will require a concerted interagency research effort.

A copy of the FDA’s Center for Food Safety and Applied Nutrition Three-Year Plan for Research in Support of the National Food Safety Initiative and Produce and Imported Food Safety Initiative can be found on the Center for Food Safety and Applied Nutrition's website (http://www.cfsan.fda.gov).

Significant Accomplishments from our research efforts include:

• Developed an improved PCR method for the detection of Cyclospora. Use of this method provided the first isolation of this pathogen from a food product associated with human illness. This new method has been used by FDA and the Centers for Disease Control and Prevention.
• Developed and successfully tested a highly sensitive, simple method for the detecting emetic toxic produced by Bacillus cereus in highly complex foods, such as burritos, pizza, and infant formula.
• Developed a protocol for analyzing sprout irrigation water as a means of monitoring contamination of sprouts by pathogenic bacteria (Salmonella, E. coli 0157:H7 and Listeria monocytogenes.
• Successfully applied a RT-PCR method to the detection of Hepatitis A virus in shellfish, water and cilantro.
• Developed a multiplex PCR method (method capable of testing for multiple genetic features) to characterize new and unusual strains of pathogenic E. coli. This method simultaneously characterizes five genetic features: shiga-like toxins (Stx1 and Stx2), intimin (eaeA), virulence plasmid (p0157), and uidA. This method allows FDA to recognize and consider a much broader range of enterohemorrhagic E. coli than is possible by the current 0157:H7-specific methods that FDA currently uses.
• Developed alternative assays to animal tests; a cytotoxicity assay and a sodium channel binding displacement assay, as potential replacements for the marine breve toxin mouse assay.
• Improved the analytical method for detection of Vibrio parahaemolyticus and transferred this technology to FDA and State regulatory laboratories.
• Demonstrated that surface heating is an effective method to improve safety of apple juice by reducing microorganisms, including E. coli 0157:H7. An accompanying thermal penetration model was developed which showed that there is minimal penetration of heat below the surface of apples during use of the inactivation technique.
• Developed an improved procedure for the quantification of a natural toxin--patulin in fruit juices and demonstrated that patulin levels on apples are a reasonable indicator for dropped and bruised apples.
• Determined that a Salmonella enteritidis population with a higher rate of mutation (mutator population) has an adaptive advantage over non-mutator counterparts during the course of infection of C57B1/10 mice. The ability of the mutator pathogen to generate genetic variants during infection may be a prime means by which this pathogen avoids antibodies and other antimicrobial measures, and thus escapes the host's immune defenses.
• Evaluated the inactivation of C. botulinum spores using high-pressure techniques (appropriate combinations of time, temperature, and pressure). These techniques may be utilized to preserve taste and quality as well as improve safety of the product.
• Collaboratively, with the University of Mississippi, developed a test strip assay for linear diamines (cadaverine and putrescine) in tuna. The test strip is used to indicate spoilage.
• Established a mouse model to describe the immune response to staphylococcal enterotoxin.
• Collaboratively with the Joint Institute for Food Safety and Applied Nutrition, held a public meeting to evaluate the needs of the risk assessment community and launched a risk analysis clearinghouse web site.
• Initiated risk assessments for Listeria monocytogenes and Vibrio parahaemolyticus.
• Evaluated the potential for Salmonella Hartford and Escherichia coli 0157:H7 to infiltrate and grow in intact fruit. Provided the data to FDA regulatory scientists and the National Advisory Committee on Microbiological Criteria for Foods to assist them in addressing public comments related to the proposed Juice HACCP Rule.
• Identified a pre-enrichment broth for the simultaneous recovery of both Salmonella and Listeria, which is superior to other media for recovering Salmonella from certain dairy products (liquid milk), resulting in substantial time and cost savings. This technology has been successfully used by both FDA and industry laboratories.

Through the availability of increased funds, the President's Food Safety Initiative has advanced our acquisition of scientific knowledge and techniques that are invaluable to expanding our understanding of food safety and food safety issues. In particular, these accomplishments serve to illustrate the diversity and the focus of the Center's research efforts to support and advance the goals of the National Food Safety Initiative and the Produce and Imported Food Safety Initiative. Furthermore, these examples illustrate the effort the Agency is expending to ensure food safety practices and programs are based on sound, high quality science.

Food Safety Initiative Staff E-mail: chammett@cfsan.fda.gov

Office Number: (202) 260-8920 · FAX (202) 260-9653 CFSAN Web site: http://www.cfsan.fda.gov/