Dr. Robert Buchanan, senior science advisor to the Center for Food Safety and Applied Nutrition (CFSAN) of the Food and Drug Administration (FDA), shared his thoughts about advances in food science research and where science will lead us into the next century.

Q: Over the past 100 years what have been the major scientific breakthroughs in food science?

A: In 1906, with the passage of the Pure Food and Drug Act, the government was able to gain control over the economic adulteration of food and inappropriate use of chemicals. From there, the entire discipline of food science developed to the point today where there is a system in place that identifies risks in foods. We have moved from a system that began as "buyer beware" to HACCP—Hazard Analysis and Critical Control Points, which is based on the producer anticipating hazards and preventing them. There is now a safety net under the entire food system.

Microbiology was a new science at the turn of the century. Chemistry and toxicology had not been around too long. Here is a good example of the progress we are making: During the last 25 years the standard technique for isolating low levels of Listeria in food took one month. Now, gene-based systems can identify Listeria in six hours. This has helped reduce by 60 percent the incidence of listeriosis in the last 10 years.

Q: Where do you expect science to take us as we look ahead to 2010—the first decade of the new century?

A: Nothing in the food industry stays the same. Food changes, the marketplace changes, the demographics of the population changes. This results in new challenges and new food safety problems. Science will provide us an ability to anticipate and rapidly respond to threats to public health. The translation of knowledge we've gained in the last ten years will turn into practical solutions in the next ten years. For example, in the 1990's it became apparent that foodborne pathogens start on the farm. It is now the job of science to identify those pathogens and identify methods for reducing or eliminating them.

Q: We hear talk all the time about a science-based inspection system. What does that really mean?

A: We will enhance the science-base of our food safety system by providing inspectors and investigators with scientific tools, new ways of looking at information, and looking at information in a more scientific manner, such as risk assessment. We want to provide scientific data and concepts to the policy-makers so that regulations are sound.

Q: How will we know if the food supply is getting safer?

A: That question is fraught with dilemma. If you look at the incidence of disease, it is going down. However, we now have improved surveillance techniques and a greater ability to detect outbreaks. We are making improvements faster in surveillance than we are in prevention. I believe we will start to see the numbers drop—we already are—as the preventative strategies take effect. In the last few years, for example, we have seen the number of illnesses from Salmonella Enteritidis in eggs decline 44 percent.

Q: If there continues to be "emerging pathogens," will we ever "win the war" against foodborne illness? Can we come up with adequate prevention systems?

E. coli O157:H7 A bacterium that can produce a deadly toxin.

A: The continuing emergence of highly infectious pathogens presents new challenges. We can't rest on our laurels. We have learned some pretty important lessons about infectious disease in general. Now we are learning about multi-antibiotic resistant bacteria—an important area of concern. The globalization of the food trade results in unique challenges. We now must concern ourselves with emerging pathogens around the world because they will likely get to our borders. We no longer have geographical barriers to disease. We will need to develop other systems to replace those.

To understand how much the world has changed we need to go back to the 1950's and the creation of the dinner salad. Before the 1950's raw salads were not a big item in the diet. Raw agricultural commodities were not readily available year-round. Even people who lived on farms ate very little fresh produce. People had to cook their food extensively to avoid getting sick.

Cantaloupe is another good example of how change in nutritional recommendations and consumer preference is creating challenges for food safety. If you go back 30 years, cantaloupes were available two weeks a year on a local basis. Now consumers want cantaloupes year-round and get them. They are available because of transportation improvements between North and South America.

I am not suggesting we give up fresh fruits and vegetables, they are a critical component of a healthy diet. However, we need to realize there will always be changes in the food system that will impact food safety, and we need to be ready for them.

Q: It seems as though the list of foods "at-risk" consumers should avoid is growing. Do you think that list will continue to grow?

A: No, I don't believe the list will continue to grow. As problems become apparent we mobilize the scientists to seek answers. For example, there is now a consumer advisory out about eating raw sprouts. Our researchers are working with industry to improve the safety of sprout production. The scientific knowledge gained has allowed FDA to recently develop and release detailed guidance on how to produce safer sprouts. Once industry conforms to those recommendations the public health advisory may no longer be needed.

In FY 99, FDA's Center for Veterinary Medicine (CVM) conducted food safety research programs in two distinct thematic areas: 1) antibiotic resistance in the pre and postapproval animal production environments and 2) the microbial quality of animal feeds. Antibiotic resistance as it relates to zoonotic pathogens is directly related to CVM's mission, regulating the safe and effective use of drugs for use in foodproducing animals. Development of antibiotic resistance in zoonotic pathogens is a critical human food safety issue impinging on the safe use of antimicrobials. CVM also regulates animal food. "As many feed components for foodproducing animals harbor foodborne pathogens such as Salmonella, it is important to understand the potential role feed may play in transmission of zoonotic pathogens to man," stated David Wagner, Ph.D., a research animal scientist at CVM. Wagner also noted that "it is also important to understand how microbes associated with feed commodities influence the development and dissemination of antibiotic resistance within the environment."

Pamela Chamberlain, DVM, DABT, an FDA food safety toxicologist, collects blood from a lactating dairy cow for a study of drug clearance into milk.

Intramural research efforts on antibiotic resistance have centered on development of research to monitor, or identify, the patterns and types of antibiotic-resistant zoonotic pathogens at the retail and animal production levels and studies focusing on development and dissemination of antibiotic resistance within the animal production environment. "This twopronged approach is designed to provide information about the types of resistant pathogens reaching the consumer which, when coupled with the other research results, will help to formulate prudent use strategies to minimize or mitigate resistance development," noted David White, Ph.D., a research microbiologist at CVM. Current monitoring activities are focused on characterizing the microbial quality of animal feeds and the types of antibiotic susceptibility patterns among E. coli, Salmonella, and Enterococcus spp. isolates obtained from retail ground beef, ground turkey, ground pork and farmraised fish. Additional monitoring activities are focused on characterizing susceptibility patterns to veterinary E. coli, Salmonella, and Enterococcus isolates from swine and poultry production facilities.

Another surveillance activity is CVM's participation in the PulseNet program sponsored by CDC. "CVM's involvement with this epidemiological surveillance tool provides a critical link to the animal production environment for traceback studies during outbreaks of foodborne illness. Research efforts on development and dissemination of antibiotic resistance in shiga-like toxin producing Escherichia coli (STEC), Enterococci, and Salmonella spp. as a consequence of antibiotic use in aquaculture, swine and poultry facilities are also underway.

CVM's extramural research program is designed to complement and augment its intramural research plan. Six of the FY 99 projects are designed to elucidate the prevalence and risk factors associated with the dissemination of antibiotic resistant Salmonella, E. coli O157:H7 and Enterococci within the animal.

"It will take a multi-faceted approach to solve the international problem of sprout safety, but it can be done," said Michelle Smith, Ph.D., an FDA policy expert on sprouts. The need to find an answer is real. Since 1995 over 1,000 illnesses in the U.S. attributed to the consumption of raw sprouts have been reported.

"In FY 99 a comprehensive sprout policy was formulated that includes a mix of research, education, guidance, and if necessary, regulation," said Smith. "Recent surveys and research have provided valuable information on seed contamination, current industry practices, and treatments and tests that can reduce the risk of sprouts serving as a vehicle for foodborne illness."

Smith said laboratory science has built a solid foundation for understanding of the problem and will offer new strategies for the elimination of microbiological hazards on sprouts.

Mary Lou Tortorello, Ph.D. and Karl Reineke harvesting sprouts at the National Center for Food Safety and Technology in Illinois.

Much of the sprout research is being conducted at the National Center for Food Safety and Technology (NCFST)—a consortium of government, industry and academia devoted to food safety research—in Summit-Argo, Ill. In FY 99, the center focused its work on prevention and intervention strategies and exploring alternatives to chlorination. These include thermal processing, disinfection with hydrogen peroxide and electron beam treatment. Most treatments would be affordable even by the small firms that dominate the industry. E-beam treatment would take place in bulk at a seed company or distribution plant.

NCFST also worked on validating rapid test kits for detecting pathogens in sprouts and spent irrigation water, the water that has flowed around and between sprouts during their production.

In FY 99 FDA collaborated with the California Department of Health and the sprout industry to produce a training video for sprout producers. The video is based on California's sprout training program and will be consistent with FDA's guidance. Distribution is scheduled to begin in Spring of 2000.

As FY 99 concluded, FDA was in the process of finalizing guidance for the sprout industry. In developing the guidance document FDA relied on the May 1999 paper, Microbiological Safety Evaluations and Recommendations on Sprouted Seeds, adopted by the National Advisory Committee on Microbiological Criteria for Foods. The report includes findings and recommendations to reduce microbial food safety hazards associated with sprouts.

Since Fall 1998, FDA has been conducting collaborative research to improve the safety of unpasteurized apple juice in response to its proposed requirement for a 5-log pathogen reduction process for juice producers who do not pasteurize their juice. Arthur Miller Ph.D., FSI research and risk assessment lead, identified six research goals:

(1) identify good harvest and manufacturing practices;

(2) develop tools to confirm effectiveness of pathogen control measures;

(3) determine the efficacy of current practices;

(4) establish critical control points;

(5) set critical limits; and

(6) identify technologies to lower incidence and levels of microbial pathogens in unpasteurized apple cider.

Cathy Melvin, an FDA microbiologist, samples apples at the Placerville, Calif., research facility

Research is being conducted at a leased commercial cider mill located near Placerville, Calif. Partners with FDA in this effort include the California Department of Health; the El Dorado County (Calif.) Department of Agriculture; the University of California at Davis; the Illinois Institute of Technology National Center for Food Safety and Technology; and USDA's Agricultural Research Service, Eastern Regional Research Center. FDA's mobile laboratory provided on-site analytical support to research teams.

The researchers have been counting bacteria, yeasts, molds and determining mycotoxin levels at several stages of juice making. The project covers several processing methods, including washing of apples using chlorination, ozone treatment, ultraviolet light treatment, and surface heat treatment, either by hot water or steam.

Miller said that many of the findings are not surprising, such as the fact that there are higher microbial loads on dropped apples versus tree-picked apples, and there are also significant increases in bacterial counts in fruit with bird pecks.

"A major achievement this year was the identification of a non-pathogenic E. coli with an antibiotic resistance marker. The strain has been inoculated onto apples and used to determine effectiveness of various intervention technologies," said Miller.

Promising pre-pressing research results include the use of hot water to wash apples, resulting in a 2-log reduction of bacteria on apple surfaces. Cornell University research on post-processing technologies indicates that UV light can produce up to a 5-log reduction.

Plant sanitation is an important factor in reducing the accumulation of bacteria, yeast and molds. Miller said that FDA research shows accumulation on the seam of the conveyor belt, dump tank, the hammer mill and filter cloths, pomace pump and collection and bottling tanks.

In July 1999, FDA hosted a meeting on improving the safety of fresh apple cider and shared research results with industry representatives.

"By next year there should be technologies that are validated and ready to go for industry to achieve a significant pathogen reduction," said Miller. "Without the use of heat pasteurization of cider, a combination of linked preventive and intervention measures will have to be used."

Not all research is conducted in a laboratory. As part of the President's Food Safety Initiative, FDA and USDA's National Agricultural Statistics Service were directed to work together to establish a baseline description of current agricultural practices used in the production of fresh fruits and vegetables in the United States. Plans were to establish this baseline by interviewing growers and packers of fresh fruits and vegetables and to conduct a survey every two years to measure change in agricultural practices.

In FY 99 a pilot survey of growers and packers was conducted in California and New York. According to Sara Fein, consumer science specialist with FDA's Consumer Research Team, "The purpose of the pilot survey was to test the survey instrument, sampling procedures and data collection procedures to ensure the results will provide the desired information." California and New York were selected for the pilot because of the diversity of growing conditions, crops and industry characteristics.

The criteria used in selecting the targeted fruits or vegetables include: (1) produce that are included in the top 20 fruits and vegetables consumed in the United States; (2) produce that use the greatest number of planted acres in the United States; and (3) produce that is traditionally consumed uncooked.

In 2000, 14 states will be in the national survey. These states are Arizona, California, Florida, Georgia, Michigan, New Jersey, New York, North Carolina, Oregon, Pennsylvania, South Carolina, Texas, Washington and Wisconsin.

Fein said the data from the national survey will be used to identify and support food safety research priorities and to develop educational outreach programs for growers and packers.

Risk assessment is a valuable tool for evaluating the public health impact of microbial contamination of food. In FY 99 three new risk assessments were undertaken.

• Listeria monocytogenes — a bacterium that occurs widely in both the agricultural and food processing environments. Although frequently present in raw foods of both plant and animal origin, it also can be present in cooked foods due to post-processing contamination. Ingestion of L. monocytogenes can cause serious human illness, particularly for pregnant women, the elderly or those who are chronically ill or have compromised immune systems. The risk assessment will seek and analyze three types of information: information concerning the epidemiology of foodborne listeriosis; information concerning the level of L. monocytogenes contamination of food and consumption levels of such foods; and information regarding the human health consequences of such exposure. The goal of this risk assessment is to provide FDA with the information needed to review current programs relating to the regulation of L. monocytogenes contamination in foods to ensure that such programs provide maximum public health protection.

• Vibrio parahaemolyticus — a bacterium that requires salt to grow. It is found in tidal water environments. It can be present in several types of seafood, including molluscan shellfish. The organism causes acute gastroenteritis in consumers, and, in some, can also cause septicemia and very rarely death. The risk assessment will determine the relationships between molluscan shellfish, V. parahaemolyticus and illness; assess the exposure to pathogenic V. parahaemolyticus; and produce estimates of illness for levels of pathogenic V. parahaemolyticus likely to be consumed by different subpopulations. FDA expects the risk assessment to provide the scientific underpinnings FDA needs to develop food safety policies that reduce the risk of disease resulting from the ingestion of V. parahaemolytiocus in molluscan shellfish and other seafood consumed raw.

• Foodborne pathogens associated with the use of antimicrobials in food producing animals — Food animals receive antimicrobials for growth promotion and control or treatment of infectious diseases. Food animals can carry organisms that are harmful to humans and these organisms may develop resistance when the animal is exposed to antibiotics. These resistant organisms can contaminate food products at slaughter and then infect humans who ingest the food. FDA is evaluating the risk to human health from resistant foodborne pathogens associated with the use of antimicrobials in food producing animals. FDA will use this formula to model the risk of increased duration of human illness due to resistant Campylobacter infections attributable to the use of fluoroquinolones in chickens. The model used in this assessment is a prototype for assessing risk due to the transfer of resistant foodborne pathogens from animals to humans. The goal is to protect public health by ensuring that significant human antimicrobial therapies are not compromised due to the use of antimicrobials in food animals, while providing for the safe use of antimicrobials in animals.

On July 3, 1998, President Clinton directed the Department of Health and Human Services (DHHS) and the Department of Agriculture (USDA) to develop a plan to create a Joint Institute for Food Safety Research (JIFSR). The goal of JIFSR is to (1) coordinate planning and priority setting for food safety research among the two Departments, other government agencies, and the private sector and (2) foster effective translation of research results into practice along the farm-to-table continuum.

In June 1999, the President received a report outlining the concept of JIFSR, and providing a proposed structure, operating principles, goals and outcomes and an implementation schedule.

"The result of a coordinated research effort will be the more efficient delivery of the scientific information needed to develop effective food safety guidance, policies, and regulations in support of public health goals," said V. Kelly Bunning, Ph.D., Food Safety Initiative (FSI) deputy lead scientist. Bunning explained that DHHS and USDA will have joint leadership of JIFSR and will use existing resources to support it.