FSI research projects are conceived, planned, directed, and evaluated using three guiding principles. First, the research must entail scientific excellence. Results that come from FDA laboratories must serve as the basis for regulatory policy and legal action. As a consequence FDA strives for the highest quality that can withstand critical evaluation. Second, the research must be relevant. Research projects need to provide mission critical data to support regulatory programs that are designed to lower the incidence of foodborne illness. And third, FSI research must help to meet the priorities of the Center. Those priorities are reevaluated annually by the Office of Science, which works closely with the CFSAN leadership team, who provide the overall direction for all Center activities.

Quantitative risk assessment of microbiological hazards, like research, is a key component of the FSI effort. This emerging discipline is a mathematical approach that can provide risk managers with information about the likelihood and severity of public health problems. Quantitative risk assessment merges data derived from field and laboratory studies with theoretical models. One exciting product of a quantitative risk assessment is the formulation of computer models that can provide risk managers with the ability to conduct "what-if" scenarios. Such analysis permits managers to evaluate different risk management options and to estimate the public health impact of each option. Within CFSAN, microbial risk assessment activities are managed together with research. This ensures that tactical research planning is linked to the development of databases required for microbial risk assessments.

This "three year plan research update" captures past progress on intramural and extramural FSI projects for 1999-2000, current activities in 2000-2001, and anticipated activities for 2001-2002. A few of the many FSI research and risk assessment activities are briefly highlighted below to introduce the reader to the nature and scope of these efforts.

Within CFSAN the FSI Research and Risk Assessment Staff is responsible for planning, coordinating and evaluating CFSAN's food safety research and risk assessment activities. Two important organizational changes have occurred to the Food Safety Initiative Staff during 2000. The first was the unexpected departure in August 2000 of the FSI Director, Dr. Susan Alpert. At Dr. Alpert's suggestion, her departure was used as an opportunity to realign the Research and Risk Assessment portion of the Food Safety Initiatives Staff into a component of the Office of Science (OSCI). The FSI Research and Risk Assessment Staff will continue to serve as the focal point for coordinating CFSAN's food safety research programs. It is anticipated that the relocation of these activities to the OSCI will further ensure that the FSI research and risk assessment coordination and planning endeavors are seemlessly integrated into CFSAN's total programmatic efforts.

FSI supported research efforts can be broadly divided into intramural and extramural activities. Particular effort is made to focus food safety research on those gaps in our scientific knowledge that limit our ability to effectively assess and assure the safety of the United States food supply. Programmatic priorities are identified that will help fill these critical knowledge gaps and the Center's research resources are evaluated to determine if the needed research activities can be supported within the center. Whenever possible increased interagency communication and research coordination efforts and extramural grants and cooperative agreements are used to ensure that those priorities beyond the immediate resources of the center are nevertheless pursued and fulfilled.

In addition to these research efforts, during 2000 a concerted interagency effort was expended on the drafting of a joint FDA and USDA risk assessment for Listeria monocytogenes. Also, CFSAN prepared and published its own draft risk assessment for the shellfish associated marine aquatic bacterial pathogen, Vibrio parahaemolyticus.

• The Food Safety Risk Analysis Clearinghouse, a joint effort of CFSAN and the University of Maryland under the auspices of the Joint Institute for Food Safety and Applied Nutrition (JIFSAN), is now an online resource found at www.foodriskclearinghouse.umd.edu. This resource supports risk analysis professionals who are seeking data, methods, and models for risk analysis.

• Published draft risk assessment documents and interpretative summaries for Listeria monocytogenes in ready-to-eat foods and Vibrio parahaemolyticus in raw molluscan shellfish. These risk assessments significantly advance the discipline of microbial risk assessment and could be used to evaluate research area needs and public health policy. The documents are available electronically at www.foodsafety.gov and www.foodriskclearinghouse.umd.edu.

FSI research priorities continue to focus on the following areas:

• Methods for Improved Detection and Enumeration of Pathogens
  
• The impact of Food Handling, Distribution, and Storage on Food Safety
  
• Prevention Techniques to Avoid, Reduce and/or Eliminate Pathogens
  
• Understanding Antibiotic Drug Resistance
  
• Understanding Resistance to Traditional Preservation Technologies

The following project highlights provide examples of only a few of the many research accomplishments or efforts that are being pursued in these areas. The relevant project number is listed in bold type after each highlight.

• Developed an alternative method to animal and tissue culture assays for the detection and quantitation of the emetic toxin produced by Bacillus cereus. (1)

• Significantly increased sensitivity and specificity has been achieved using modified RNA isolation and amplification procedures in the method for detecting Hepatitis A virus in shellfish and produce. (1)

• Initiated development of DNA chip microarrays, and demonstrated that discrimination between Salmonella, Shigella and pathogenic E. coli including 0157:H7 can be achieved using primers for six genes encoding antigenic determinants and virulence factors. (1)

• Developed a protocol and succesfully tested a method for use in testing large volumes of unpasteurized juices for the presence or absence of E. coli to verify effectiveness of HACCP. (2)

• Determined the growth and survival potential of Staphylococcus aureus, Listeria monocytogenes and Campylobacter jejuni on cilantro, lettuce and green peppers that were stored at refrigerated temperatures in air, vacuum and high carbon dioxide atmospheres. (3)

• Demonstrated that spent irrigation wash water can be used to rapidly detect the presence of food pathogens in sprouts. (3)

• Developed an improved procedure for the quantification of the natural toxin patulin in fruit juices and demonstrated that patulin levels in apples are a reasonable indicator for dropped and/or moldy apples. (3)

• Completed a study that demonstrated there was no significant difference in the effect of gamma and electron-beam irradiation at 5-50 kGy doses on migration of low molecular weight oligomers from packaging materials into food simulating solvents. (3)

• Evaluated Vibrio tubiashii (isolated from diseased mollusks) for virulence factors that may enable it to be a human pathogen. A cytolysin (cytotoxin/hemolysin) that is related to the Vibrio vulnificus cytolysin, and a hemagglutinin similar to the hemagglutinins of other pathogenic vibrios were purified and characterized. (5)

• In collaboration with Cornell University and Centers for Disease Control a method for the UV-inactivation of Cryptosporidium parvum in apple cider was developed which has the potential to treat large volumes of cider with a greater than 5 log level of inactivation of this parasite. (6)

• Published a PCR method for extracting and detecting viruses from oysters that proved effective in the investigation of an outbreak consisting of 171 cases. The identical clinical strain of Norwalk-like virus was identified in recalled oysters, where it was present at low levels, confirming the oysters as the source of the outbreak. (7)

• Completed data analysis and submitted final report to the ISSC on the project, "Vibrio vulnificus and Vibrio parahaemolyticus in Retail Shell Oysters, A National Survey". Data from this study were used in the V. parahaemolyticus Risk Assessment. (8)

• Demonstrated a synergistic effect between pulsed electric field (PEF) energy and thermal energy on the destruction of Listeria monocytogenes that increased reduction from 1 log at temperatures below 55 °C to 4 logs due to PEF energy alone at 55 °C. In contrast a maximum 3 log reduction was found for E. coli O157:H7 due to PEF energy alone while no synergism with thermal energy was noted. (9)

• Two Fusarium metabolites were isolated for toxicological studies. (10)

• Methods were developed or evaluated for ochratoxin A in wine and beer, patulin in apple juice, and moniliformin in corn. (10)

• Preliminary data indicated that food matrix does have an effect on the dose of Salmonella required to cause disease. (11)

• Demonstrated progress on adapting an electronic sensor instrument ("electronic nose") to distinguish several levels of spoilage in fish while also recognizing the fish species. (12)

• Established the importance of house flies as an environmental risk factor at the farm level in the transmission of Salmonella Enteritidis in table eggs. (14)

• Funding for large-scale studies of Salmonella in chicken was obtained through the USDA in collaboration with University of Maryland and USDA's Agricultural Research Service (ARS). (15)

• In collaboration with the University of Georgia, a model was developed using Rhesus monkeys to determine the dose response and immune parameters associated with Listeria monocytogenes-induced stillbirths. (17)

• Several in vitro assays were developed to determine L. monocytogenes virulence. (17)

New Intramural Programs

An intramural Awards for Technical Support program was initiated in 2000. This program provides the opportunity for CFSAN researchers to compete for funds to support either post doctoral or temporary laboratory technician assistance. Six awards were made in particular areas of program interest and concern including, enteric viruses, marine biotoxins, mycotoxin control, and emerging technologies for rapid detection of pathogens. A more complete description of these projects is presented in Appendix C.

• Development of an instantaneous fluorescence assay to detect PCR-amplified Norwalk-like virus and Hepatitis A virus in seafood.

• Profile of gene expression in Hepatitis A virus infected cells.

• Optimizing strand displacement amplification (SDA) for pathogen detection and quantification in the field.

• Determination of mutagenic potentials in milk from lactating dairy cows fed, aflatoxin-containing, aflatoxin-decontaminated, and aflatoxin-free feed.

• The concentration of pathogens from food and environmental samples to support their "real time" detection.

• The characterization of pathogenic aquatic eucaryotes and their toxins.

Selected New Cooperative Agreements

• FD-U-00-1942-01; Development of Methods for Virus Extraction from Foods, awarded to Lillian Marcus Stark, Florida Department of Health. Although advances have been made in detecting Norwalk-like viruses in foods, currently there are no standardized methods suitable for routine monitoring and outbreak investigation. This project proposes to develop simple, reliable methods for extraction and detection of viruses from a variety of food products.

• FD-U-00-1950-01; Home Refrigeration Knowledge and Practice of Consumers, awarded to Sandra L. Godwin, Tennessee State University. The goal is to obtain information to support the science behind the U.S. Public Health Service Food Code, which provides guidance to the retail and food service industry, as well as information to support guidance to the consumer.

• FD-U-00-1964-01; Surrogates for Evaluating Efficacy of Thermal Processes, awarded to David Ernest Gombas, National Food Processors Association. The National Food Processors Association has established process recommendations for pasteurization of juices, and thermal processing of hot dog batter, chicken meat and surimi-based imitation crab. This study will be conducted (1) to identify potential surrogate organisms for evaluating adequacy of the recommended health processes and (2) to evaluate the utility of their use for validating the processes in inoculated pack studies.

Selected Continuing Cooperative Projects

• FD-U-001622-01; Development of a Risk Assessment Dose-Response Model for Food borne Listeria monocytogenes, awarded to Mary Alice Smith, University of Georgia. The goal of this proposal is to develop a dose-response model of L. monocytogenes using pregnant rhesus monkey as surrogates for immunocompromised subpopulations.

• FD-U-001626-01; Disinfection of Alfalfa Seeds and Sprouts, awarded to Larry R. Beuchat, University of Georgia. The objective of this study is to determine the effectiveness of several food-grade chemicals and natural antimicrobials in killing E. coli O157:H7 and Salmonella spp. during the treatment of alfalfa seeds and/or sprouts for the purpose of minimizing the risk of illness.

• FD-U-001627-01; Natural Variation in Escherichia coli O157:H7, awarded to Frederick Blattner, University of Wisconsin. The purpose of this award was to determine sequence information of Escherichia coli O157:H7 to provide unique insights into the evolution, survival, and growth of this pathogen with respect to its virulence factors. (see Nature, January 25, 2001, Volume 409, pages 529-533)

Selected Completed Cooperative Projects

Unpasteurized Apple Cider - was a unique two year collaboration that leveraged resources among FDA, USDA-Agricultural Research Service, California Department of Health Services, El Dorado County-California, University of California at Davis, the Illinois Institute of Technology, and other institutions. FDA leased a small cider mill, moved a mobile laboratory on-site and provided laboratory and cider making expertise to permit researchers to conduct studies in a commercial situation. Technical contributions provided a better understanding of harvest, washing, pressing, and post pressing treatments that serve as the basis for the Juice HACCP regulation and guidance to industry and to FDA inspection personnel.

Dose-response Data from Foodborne Illness Outbreaks - was a collaborative effort with the Department of Public Health, City of Chicago and the State of Illinois. A study was completed to develop a framework document describing a system for obtaining dose-response data by intensively studying foodborne illness outbreaks.

Each entry provides a narrative description of the research area the project is intended to address, a series of "deliverables" that can serve as milestones for evaluating progress, and the resources devoted to each project. In the electronic version of the document instant access to the specific page location of a project is available by "double clicking" on the desired item in the table of contents. The administrative liaison(s) responsible for oversight, coordination, and reporting activities associated with each project is identified. Questions concerning the research plan projects or accomplishments may be directed to Dr. Art Miller, Dr. John Newland, or the specific project Administrative Liaison.

Table of Contents

Hypertext updated by dav 2001-OCT-04