IAFP 2003
Session Summaries

Members of the IAFP Student Professional Development Group assisted the convenors by serving as Session Monitors at IAFP 2003. Student Monitors prepared the following session summaries for presentation in Food Protection Trends.

Plenary Session – Breaking the Cycle of Foodborne Illness: The War on Pathogens
S01 – Use of Food Safety Objectives and Other Risk-based Approaches to Reduce Foodborne Listeriosis
S02 – Intervention Strategies for Ready-to-Eat Meat Products
S03 – Hazard Identification in the Fresh Produce Industry
S04 – Recipe for Food Safety at Retail
S05 – Effective Food Worker Hygiene Interventions: A Risk Assessment Approach
S06 – Investigative Molecular Techniques and Their Application to Food Safety
S07 – Current Issues in the Microbiological Safety of Dairy Foods – From Farm to Table
S08 – Hot Topics in Seafood Quality and Safety
S09 – New Horizons in Diagnostic Food Microbiology
S10 – Food Allergens: Past, Present and Future
S11 – Costs of Industry and Government Food Safety Actions: What is at Stake?
S12 – Spoilage and Pathogenic Fungi and Yeasts
S13 – Assuring Food Safety and Security
S14 – Applied Microbiological Genomics for Food Safety and Quality
S15 – Campylobacter: A Pathogen in Need of Resolution
S16 – Microbial Stress Response to Intervention Technologies
S17 – Current Issues in Food Toxicology
S18 – Science-based Shelf-life Dating of Ready-to-Eat Refrigerated Foods
S19 – All the Latest Jazz – Recent Foodborne Disease Outbreaks
S20 – Food on the Move
S21 – Aquaculture:  Safety and Quality Issues
S22 – The Evolution of Foodborne Pathogens
S23 — Natural Antimicrobials — Current Trends and Future Perspectives
S24 – Risk Communication – Putting Food Safety in Perspective
S25 – Emerging Issues in Water Quality for the Food Industry
T01 – Microbiological Methods
T02 – Food Safety Management and Communication
T03 – Produce Microbiology
T04 — Food Handling in the Domestic Food Service Environment
T05 – Foodborne Pathogens
T06 – Risk Modeling

Plenary Session – Breaking the Cycle of Foodborne Illness: The War on Pathogens
Dr. Elsa Murano, USDA

Renee M. Raiden, Virginia Tech and Benjamin Chapman, University of Guelph

At the plenary session during the IAFP Annual Meeting, Dr. Elsa Murano, the current under secretary for food safety at the United States Department of Agriculture (USDA) spoke of the past, present and future of food safety in the US. She informed the audience that while the United States has the safest food supply in the world, we still must work harder in the future to attempt to continue reducing and/or eradicate incidence of foodborne illness. She began with several main accomplishments that have been met while working towards this goal.

The first accomplishment stated was the improvement of management and control of regulatory programs. There are currently 107 trained consumer safety officers in the Food Safety Inspection Service (FSIS), and an automated import information system is being implemented. The agency gave assurance that all policy decisions are, and will be based on science. Proof of this is seen in the new regulations for procedures of Salmonella testing, new ground beef regulations, as well as the zero-tolerance ruling for Listeria monocytogenes in ready-to-eat meat products. Another accomplishment has been in the improvement of coordination between food safety agencies and other public health agencies. Recently there has been a memorandum of agreement signed between states to aid in cooperation during recalls. A fourth accomplishment mentioned was the enhancement of public education of food safety issues. Consumer education has been achieved through press conferences, live broadcast interviews and cooking demonstrations. In addition a new USDA food safety mobile has been created to travel the across the US and aid in food safety demonstrations. Finally, the USDA has strengthened coordination between government agencies as a response to the heightened terror threat since September 11th in order to protect meat, poultry and egg products from intentional contamination.

Dr. Murano announced that a new FSIS initiative that is currently being implemented. As part of the initiative, the agency is striving to update training programs and create a public health focus by integrating the scientific and technical principals in food safety. This includes a HACCP validation program. Improvements in training will include locating training facilities as close to employee worksites as possible and implicating regional and interactive computer training sessions. Finally the agency will strive to place a priority on risk assessments and attempt to coordinate these with other government and public health agencies.

Finally, Dr. Murano completed her presentation by discussing how to take food safety to an enhanced level in the future. Suggestions include being able to anticipate hazards in the future and predict their risks, in attempts to ensure corrective measures are taken. Coordination between government, public health organizations and industry is essential to ensuring food safety in the US forward in the future.

S01 – Use of Food Safety Objectives and Other Risk-based Approaches to Reduce Foodborne Listeriosis

Leslie K. Thompson, Kansas State University and Yohan Yoon, Colorado State University

The first steps in developing a food safety plan to control Listeria monocytogenes are identifying a baseline, identifying at-risk populations, and identifying “High-Risk” foods along with other considerations such as virulence and dose response. Some control strategies are to reformulate foods, prevent post-packaging contamination, achieve acceptable storage times, and educate those who would be most susceptible to listeriosis. Recently, hazard characterization issues raised in 96% of all cases of listeriosis include virulence, human infectivity, host susceptibility, and infective dose. The infective dose response is based on the interaction between the food matrix, the pathogen, and the host. For Listeria, the infective dose is accepted as high but there are some outbreak cases where the infective dose was low due to lack of testing methods for L. monocytogenes. Therefore, a better understanding of physiology and stress response as well as improved detection may change the thoughts on infective dose.

The factors that are considered in primary exposure assessments of L. monocytogenes are prevalence and population of the microorganism; amount and frequency of food consumed; and potential for growth of L. monocytogenes at refrigeration temperatures are all. In an exposure model, all segments of the food system have a role from farm to table. Each step of the process can increase, decrease or maintain microbial population in the food. Time, temperature, food matrix, pH, acidity, water activity, preservatives, competitive flora, and processing treatments are all essential to determining the possibility of risk in a food. An important part of the continuum that has not been studied well is the persistence of the organism in the home. In addition, there is a need to establish information regarding food safety objectives and microbial criteria, and the impact of risk assessment. Also, food safety activities should be linked to public health outcomes. A food safety objective is the maximum frequency and/or concentration of a microbial hazard in a food at the moment of consumption that appropriately provides a level of protection established as both a scientific and society decision. A risk assessment articulates a public health goal, and a level of exposure must be calculated to achieve that goal. It must then be determined if this is feasible and can industry implement the standard. To reduce listeriosis the goal of strategies should be to reduce exposure of high-risk individuals, prevent growth, prevent contamination, educate, formulate food to prevent or slow growth of organisms, and limit time-temperature abuse. Because human behavior is a major factor in incidences of listeriosis, educating consumers and food handlers about knowing risks and prevent strategies should also be incorporated into food safety programs.

S02 – Intervention Strategies for Ready-to-Eat Meat Products

Adriana Velasquez, University of Nebraska-Lincoln and Marcos Sanchez, University of Nebraska-Lincoln

The session included topics related to intervention technologies that are used by Ready-to-Eat (RTE) meat processors to control the presence and populations of pathogenic bacteria. Technologies such as post-packaging thermal pasteurization, ingredient formulation, and non-thermal processes were discussed in the session. Initially, Bruce Tompkin from ConAgra discussed the development of Food Safety Objectives (FSO) in Ready-to-Eat meats.

The presentation focused on the presence of Listeria monocytogenes (Lm) in these types of products, including non-cured poultry products. The use of FSOs should be considered for in pack pasteurization processes, for the use of additives incorporated to retard or prevent the growth of Lm and for the validation of code dates for safety.  The second presentation included two speakers from Wayne Chemical Co. David Herweyer and Oliver Reeban. The talk focused on the use of chemicals and other sanitizers in manufacturing operations. Videos demonstrating the application of different sanitizing agents on equipment and plant facilities were shown. The presentation concentrated on a product based on Alkalyne Hydrogen Peroxide (AHP). AHP was shown to be effective to control L. monocytogenes in plants due to strong oxidizing activity. Some other recommendations were detailed including the elimination of all standing water in manufacturing facilities, the atomization of plant rooms from ceiling to floor to avoid cross contamination, and the usage of plastic wheels instead of rubber due to the potential damage that could be caused by the sanitizing agent. Kathleen Glass from the University of Wisconsin provided a thorough summary of the different additives used in ready-to-eat operations to control pathogens. In order to select the appropriate additive to be sued in an operation, it was recommended to consider several issues including regulations, labeling requirements, consumer acceptance, allergen potential, functionality, sensory effects, costs, packaging, processing storage conditions, pathogen of concern and the efficacy of the product. Efficacy should be estimated based on several properties including solubility, dissociation constant, product pH, synergistic effects between additives, temperature and the potential presence of resistant populations of bacteria. Several additives and associated benefits in meat products were discussed, including the use of nitrites, lactates, diacetates, citrates, phosphates, bacteriocins and new products such as lactoferrin and monolaurin.

Lisa Szabo from Food Science Australia described various non-thermal intervention options to be used in ready-to-eat meat products. One of them is Pulsed Electric Field, which causes the buildup of electrical charge at the cell membrane of the bacterial cells, increasing its permeability, causing the eventual death of the cell due to leakage. Limitations associated with this technology include the lack of inactivation of spores and some food enzymes. Another described example was high-powered ultrasound, which causes cells to collapse due to changes in pressure. This option appears to be environmental friendly but could cause problems due to the possible lack of uniformity of treatment throughout the product. Dr. Harshavardhan Thippareddi from the University of Nebraska-Lincoln presented various alternatives for the thermal post-pasteurization interventions of ready-to-eat meats. Type and composition of the product, packaging, orientation and package design are among the aspects that will determine the appropriate intervention technology to be used. From a different perspective, Kevin Nanke from SureBeam Corporation described the mechanism and effects on the product involved in irradiation of food. He mentioned the increasing consumer awareness of electronic irradiation as well as the growing acceptance of irradiated products available in the market.

S03 – Hazard Identification in the Fresh Produce Industry

Montserrat Hernandez, Universidad Autonoma de Queretaro, and Glenner Richards, University of Georgia

The presentations that were made during this session identified potential sources of foodborne pathogens that contaminate produce and examined pre- and postharvest factors that are potential hazards for the safety of fresh produce. Drs. Barry Michaels (Georgia Pacific) and Ewen Todd (MSU) discussed the significance of food worker hygiene. Lack of barriers, such as gloves, was identified as the main source of pre- and postharvest contamination. Activities in some Central and South American countries where raspberries, cantaloupes and mangoes have been identified as vehicles of foodborne diseases were observed. Problems associated with field worker hygiene in these areas included high endemic rates, lack of chlorinated water, lack of appropriate supplies and facilities, training difficulties and domestic issues such as child care.

Dr. Trevor Suslow (UC Davis) focused on the prediction of bacterial pathogen presence and behavior. Index, indicator and surrogate organisms were defined and described. An on-farm reservoir microbial survey was undertaken to develop baseline data of non-pathogenic E. coli. The results presented indicated that there is no correlation between E. coli and thermo-tolerant coliforms found in on-farm reservoirs. Positive E. coli/coliform results from water and plant samples were not an indicator of fecal contamination. Without confirmation, MPN tests greatly overestimate E. coli, because there are interfering genera. The survival of pathogens on produce was dependent on the arriving population.

Dr. Lee-Ann Jaykus (NCSU) presented data from a multi-institutional collaborative field study (Clean Greens) to assess the microbiological quality of domestic produce (433 samples–cantaloupes and leafy greens). Microbiological quality of produce in the field varied among and between produce types. Salmonella was detected only on cantaloupes, while Listeria monocytogenes was not isolated from any samples. Most farms and sheds used good agricultural practices, however the contamination level on cantaloupes increased during postharvest processing (washing). This was associated with the wash water quality.

Dr. Jack Guzewich (FDA/CFSAN) highlighted FDA findings with respect to farm investigations of foodborne disease outbreaks associated with produce. Outbreaks associated with produce of domestic and foreign origin continue to occur. The major factors involved are worker hygiene, wild and domestic animal presence in the fields as well as postharvest handling facilities, harvest tools and equipment and water sources. Water quality was identified as the main issue of concern.

Dr. Yuhuan Chen (NFPA) discussed the results of a survey conducted in two states (Maryland and California). Overall, there was low prevalence (0.74%) of Listeria monocytogenes in bagged vegetables in both states. However, there were differences between locations (MD: 0.5%; CA: 0.9%). The data collected has been used by NFPA to conduct Listeria monocytogenes risk assessment, FDA/FSIS to perform risk modeling and FSIS in-plant dynamic model for deli meats.

Dr. Mark Walderhaug (FDA/CFSAN) described the information needs for transportation and distribution component of a produce risk assessment. It was concluded that the difficulty of the transportation and distribution module was dependent on the risk manager’s wants and needs. Data collection was expensive and could affect the company’s competitive advantage. Transparency of some risk assessment may have to be sacrificed for security concerns. Currently, there is no complete risk assessment from farm to fork for produce.

S04 – Recipe for Food Safety at Retail

Kristen Matak, Virginia Tech and Angie Hartman, Virginia Tech

The number of Americans choosing to buy ready-prepared and ready-to-eat meals has dramatically increased in the past decade. According to Fred Reimers of H.E. Butt Grocery Company, there has been a shift in supermarkets to a central market where over 2,000 meals are served daily. Freshly prepared meals called “home meal replacements” have become increasingly common and therefore the manufacturing process of foods is no longer limited to the “manufacturer.” Steve Otwell, from the University of Florida, suggested that the introduction of HACCP at the retail level will survive only if there is a good foundation of prerequisite programs based on science-based guidance and uniformity of regulations from state to state. To make progress in the world of food safety at the retail level, there must be a certain amount of change. Frank Yiannas of Walt Disney World offered that education of consumers and employees may be facilitated using innovative approaches such as the newly developed international food safety icons to communicate food safety and HACCP principles. The use of the internet and automated processes of digitally recording/collecting data have proven to be helpful in controlling food safety at the retail level by improving accuracy in monitoring, recognizing trends, and the ability to compare daily HACCP reports. Joe Eifert of Virginia Tech spoke in detail about the innovative International Food Safety Symbols, which are pictures alone or in combination with bilingual words that the non-English speaking workers can understand, regardless of native language, so they can perform proper food safety practices. Some of the symbols currently being used include: do not cross contaminate, do not come to work sick, and danger temperatures for food. In addition, future icons representing reheating food properly, poison/toxic substance, correct refrigeration temperature, discard date/times, and do not thaw at room temperature are being developed.

The prevalence of foodborne allergies is on the rise. Since allergens can cause health and regulatory risks, customer dissatisfaction, and business risk, the FDA requires that an ingredient must be declared on the label if an allergen is added to a food as an ingredient. Ernie McCollugh explained how managing allergies in the retail environment using the Allergen Prevention Program would help prevent allergens from becoming a problem. This program includes an allergen awareness team, training, raw material program, rework rules, packaging controls, labeling controls, and sanitation programs. Pete Snyder spoke about Food Code Variances, in cases where processes in the Food Code are modified to meet retail needs. This program is important because processors need to be allowed to perform any process that can be both validated as safe and documented by the Retail/Food Process Authorities. To perform a process variance, the manager must first expose the kitchen staff to control hazards and provide a HACCP plan. The kitchen staff must then be trained so they can begin the controlled process. Then HACCP self-inspections are performed to determine the degree of hazard so that improved HACCP action can be taken. Finally, the HACCP authority trains employees so the owner and food handlers can control hazards. Many steps are being taken to increase the level of food protection at the retail level. The importance of proper food handling has not gone unnoticed to those in charge of food safety and quality. These programs and future programs will continue to evolve so that our food supply is as safe as it can be.

S05 – Effective Food Worker Hygiene Interventions: A Risk Assessment Approach

Jarret Stopforth, Colorado State University and Yohan Yoon, Colorado State University

The safety of our food supply is constantly threatened by introduction of pathogens inherently associated with the product or as a result of environmental contamination. Among some of the most common sources of food product contamination include pests, equipment, facilities, animals and people. In any food processing facility it is inevitable that product will be subjected to human contact and may face potential contamination as a result. The risk of contaminating food and potentially introducing pathogenic bacteria is increased when food workers are infected with a communicable foodborne disease. The risk factors (and extent) associated with infected food workers transmitting disease include: (a) the lack of barriers in food preparation (90%), (b) bare hand contact with food (59%), (c) excessive handling with produce and salad preparation (31%), (d) asymptomatic carrier of disease (31%), (e) symptomatic carrier of disease (26%), and (f) preparation involving more than one food worker (23%). The progression of foodborne disease involving the food worker originates with an infected worker carrying a communicable disease which subsequently contaminates the environment, in turn contaminating other food workers, and all of which have the potential to contaminate the food and result in a rolling outbreak. It is suggested that restaurant food handlers may pose a significant risk to food product safety due to the misconception that food safety knowledge through educational programs implies safe food handling practices. The main factors linked to improper food handling practices by restaurant workers are: (a) working while ill, (b) improper handwashing, (c) cross-contamination, (d) improper glove use, (e) inadequate temperature monitoring, (f) inadequate reheating procedures, (g) improper product holding, and (h) inadequate cooling. When considering transmission of foodborne illness through food worker contamination, it is essential to consider risk assessment with both quantitative and especially qualitative data (QRMA). The factors for consideration using QMRA for mitigation strategy are directly related to the individual food handler and include: (a) exclusion of worker when infected, (b) restriction when infected, (c) hygienic practices, (d) vaccination programs, and (e) cross-contamination potential. Data for use in determining transmission potential using QMRA is based on probabilities of risk reduction or promotion with the inclusion or exclusion of certain preventative strategies. The problem with using this technique is the variability of the data, i.e., differences in contamination load (high vs. low soil) the effectiveness of hygienic practices changes but the variability of the data changes accordingly. It is estimated that 97% of foodborne illness in food establishments is due to poor food handling practices and this creates a demand for training and evaluation of food worker and manager training as it is believed that better trained managers result in production of safer food. It is important for risk assessment models to include attitude and behavioral content defined by certain psychological terms and other considerations for the models are the factors influencing training implementation and training design and delivery.

In developing countries, street vending of food is a major problem; however, it is important as a source of income and a way of life. The major cause of food safety problems in these environments include: (a) lack of education and facilities, (b) lack of training, (c) lack of compliance / enforcement, (d) inadequate facilities, and (e) inadequate infrastructure. The benefit of improving personal hygiene activities outweighs the cost of improvements as it is more profitable to prevent rather than try to cure the outcome of foodborne outbreaks which bear the burden of cost related to medical bills, loss in productivity, public health investigation, stock losses and litigation. It would be more sensible to forgo the cost of hygienic supplies (i.e. soap, towels...) than face a higher potential risk of foodborne disease outbreak.

S06 – Investigative Molecular Techniques and Their Application to Food Safety

Renee M. Raiden, Virginia Tech and Justin Ransom, Colorado State University

As the field of food science advances, molecular techniques will become essential to both detecting foodborne outbreaks and in laboratory research. This symposium exhibited how molecular techniques may be applied to food safety. Lee-Ann Jaykus from North Carolina State University gave an overview of commonly used molecular techniques including polymerase chain reaction (PCR) and pulsed field gel electrophoresis (PFGE). These techniques are being used to detect the presence of several key emerging pathogens that have been difficult to culture using traditional techniques, including Noroviruses, Cyclospora cayetanensis, Campylobacter jejuni, and Listeria monocytogenes. The use of genetic processes in investigating these pathogens was stressed and she stated that although these are expensive methods, they can significantly aid in investigative microbiology.

Martin Wiedmann from Cornell University gave an overview of molecular subtyping. In the past serotyping based on surface antigens was used as the only subtyping method, but currently researchers are using DNA-based methods, ribotyping, and PFGE to subtype bacteria. Currently the most important subtyping program for food safety is PulseNet, a collaboration between the CDC, USDA, and FDA to use PFGE for identifying strains of microorganisms to help determine if outbreaks are related. He stated that the future of investigative molecular techniques lies in DNA based sequencing of specific genes associated with specific microorganisms.

Don Schaffner from Rutgers University complemented the symposium topic by presenting a risk assessment model that incorporates molecular biology data that may be implemented by researchers in the future. As more information is gathered about the genetics of foodborne pathogens, more data about virulence, survival under stress conditions, and other factors will be available to construct risk assessment models that may be more specific to a microorganisms and food.

The role of molecular techniques in the food industry was discussed at length by Vickie Lewandowski from Kraft Foods. She described that molecular techniques could replace time-consuming conventional techniques and would provide heightened sensitivity and specificity for detection of pathogens. She noted that the widely publicized Listeria monocytogenes outbreak in fall of 2002 was tracked using PFGE, and researchers were able to link the outbreaks to each other. The creation of a confidential industry-wide database of PFGE patterns of L. monocytogenes may also provide industry with a resource to quickly identify potential outbreaks. She stressed the importance of the use of more than one method to be used for confirmation due to varying sensitivities.

Finally Franco Pagotto from Health Canada discussed DNA microarray technology. This technology involves specific DNA probes attached to a slide or membrane. Target DNA is labeled and color change is seen when the target DNA and the probes are bound. Microarray can provide vast information about the genetics of foodborne pathogens in a relatively short period of time.

S07 – Current Issues in the Microbiological Safety of Dairy Foods – From Farm to Table

Kristen Matak, Virginia Tech and Adriana Velasquez, University of Nebraska-Lincoln

Despite the fact that dairy products are widely distributed and consumed in high quantity, very few major incidences of microbial outbreaks have occurred. However, concerns over the emergence of resistant foodborne pathogens and the possibility of agricultural bioterrorism have given risk managers the task of providing safe quality foods without increasing production costs or imposing more restrictions on international trade. This is a subject that must be addressed at each phase of the food production cycle including at the farm level. Kathryn Boor of Cornell University described the findings of a literature review to understand the science behind current regulations for the production of dairy products. The importance of guidelines for the safe production of dairy products was realized early on, and in 1924 the Pasteurized Milk Ordinance (PMO) was developed. In these guidelines, the standards for the thermal treatment of milk were set according to the findings of a 1957 study by Enright that assured the destruction of Coxiella burnetti. Kathleen Kaufman of Cornell discussed the need for programs that assure food safety on the farm as well. One such program mentioned was the New York State Cattle Health Assurance Program. This program addresses three principles of biosecurity at the farm level: (1) preventing disease from entering the farm, (2) preventing disease from spreading within the animal environment, and (3) ensuring the quality of the product going off the farm. Mark Carter from Kraft Foods expressed the need for continued effort to eliminate problems in the processing plant environment. This would include, but not be limited to, validation of processes in the plant, conducting environmental sampling, assuring the quality of raw ingredients, and using indicator organisms to determine quality/safety. In recent years, much research has focused on the safety of the currently available production technologies of food items. Dr. Michael Digeronimo, from Dover Brook Associates explained the safety concerns of aseptic processing and packaging, a usual choice used during production of low acid foods. He highlighted the importance of the criteria that aseptic packaging materials should meet in order to ensure safety of both the product and the consumer. It is also required that the material also offers stability through the absence of chemical interactions with the food and its source must be acceptable for the consumer. Determining factors on the efficiency of the system include consistency during commercial sterilization of the materials to be used as well as in keeping aseptic conditions in the packaging environment. In order to ensure microbiological safety of cheeses manufactured with raw milk, the USDA mandates that the products must age for 60 days at no less than 2ºC before being consumed. The results of various studies cited by Dr. Catherine Donelly from the University of Vermont show that some pathogens including E. coli O157:H7 and Listeria monocytogenes can survive and grow under these conditions. Although post-process contamination is believed to be the greater threat to the safety of these products, screening of incoming raw milk and regular testing for Listeria monocytogenes are highly recommended. Dr. Martin Wiedmann from Cornell University discussed the need for a development of an understanding the farm to table transmission of pathogens in order to improve the system. He also highlighted the importance of being able to predict the effects that changes in the pathogen, the host, the environment and the food will have on foodborne diseases and their transmission.

S08 – Hot Topics in Seafood Quality and Safety

John Allan, University of Georgia and Hoan Jen Pang, Rutgers University

George Flick (Virginia Tech) discussed histamine production in fish. There are difficulties in tracing outbreaks due to scombrotoxin since record keeping is very poor with regard to where/how the fish were caught, how they were handled after catching, temperatures of the water in which they were caught and temperature they were held at before processing. There is a lack of research performed on scombrotoxins in fish. Some of the problems with the published studies include: (1) lack of fish history, (2) mis-identification of the microorganisms which produce histamines, (3) lack of a standard protocol for histamine testing, and (4) inconsistencies in published results. Dr. Flick pointed out that the dynamics of histamine production are unknown. Carbon monoxide-packaged fish keeps the color of the fish appealing but masks the quality degradation associated with scombroid decomposition. He recommends an expert panel be established to review research and develop protocols for processes from harvesting to consumption.

David Green (North Carolina State University) presented information on scombrotoxin production and prevention. Control is HACCP-based and limits time of exposure to temperatures associated with toxin production. The primary control is temperature which functions to limit production of histamine by bacteria. Scombrotoxin production is associated more with high temperature/short time spoilage than with low temperature /long time spoilage. Examples of control methods that can be used include: (1) evisceration of whole fish and gill removal, (2) freezing of fish, (3) high pressure treatment, (4) competitive enzymes, (5) coding of date and point of harvest, and (6) good hygiene.

Andy DePaola (FDA) discussed risk assessment of Vibrio spp. in oysters. Vibrio risk assessment performed by Codex Alimentarius should provide an excellent source for development of intervention strategies to reduce V. vulnificus illness based on several observations, including: consistent reporting of illness compared to other foodborne diseases, one predominant vehicle (oysters), raw consumption eliminates cook variability and corresponding uncertainty in thermal treatment, and Beta poison fit of model for dose response agrees with the seasonality of cases.

Rita Schoeny (EPA) discussed methyl mercury occurrence in seafood, which causes the most concern of all other heavy metals. The majority of the methyl mercury found in the environment comes from combustion point sources (87%). Methyl mercury accumulates up through the food chain with the muscle tissues of larger predatory fish having the highest levels.

Mike Russell (Gene Scan USA) made a presentation on the detection of genetically modified foods. PCR-based methods rely on genetically modified DNA (GM-DNA) being present in the food. ELISA methods, which are cheaper and easier to use, can be developed to detect protein products from GM-DNA, but require larger amounts of the protein to be present as compared to the amount of DNA need for PCR methods. Real time PCR methods give a relative amount (%) of GM-DNA in the total species DNA of the specimen being tested. The sampling size is very important for determining the presence of GM-DNA and labs should have good quality control programs established to minimize false negative results.

Douglas Marshall (Mississippi State University) spoke on the safety of ready-to-eat seafood. Controlling bacterial pathogens in seafood can be done through various means including, elimination of the microorganism from surfaces through rinses (i.e., lactic acid) and steam treatment, and through inhibition i.e., lowering temperature, adding competitor organisms, modified atmosphere packaging, and the addition of antimicrobials. To control viral levels in product, fecal contamination in the environment must be minimized. High pressure treatments have shown promising results in reducing viral loads, especially in raw oysters. Parasites can be destroyed by freezing and cooking parameters established by FDA.

S09 – New Horizons in Diagnostic Food Microbiology

Laura Bauermeister, Auburn University and Ethan Solomon, Rutgers University

The goal of this symposium was to provide an update on a variety of new technologies that have been developed to speed the microbiological analysis of foods. These include real-time PCR, biosensors, microarray technologies, and the replacement of serotyping with molecular methods. In his overview, Dr. Peter Feng summarized the difficulties associated with performing rapid methods: interference by normal flora present in the sample, the complexity of the food matrix, and the low numbers of the target organism. Because of these hurdles, most rapid methods still require a culture-enrichment step prior to analysis. Next-generation methods are focused on the shortening or elimination of the enrichment step. A second limitation of the current methods is the variation in assay efficiency; an abundance of rapid methods, and no clear comparative or collaborative evaluation between methods. Lastly, Dr. Feng illustrated how the increased speed and sensitivity of rapid methods create a regulatory dilemma for government agencies and the food industry. The use of standard methodology passes many foods that may not pass under the conditions of rapid methods. In the next lecture, Dr. Pina Fratamico explained the differences of real-time over traditional PCR. Real-time PCR utilizes fluorescent reporter probes that increase in proportion to the amount of PCR product. Advantages over traditional PCR are that real-time can be used to quantify the amount of initial template, real-time eliminates the need for time-consuming post-processing, and that it is extremely sensitive. She then demonstrated the rapid detection of Escherichia coli O157:H7 using a multiplex real-time PCR. The organism was detected in ground beef enrichments after 8 hours. Dr. Marianne Kramer presented the use of evanescent-wave fiber optic biosensors to detect pathogens directly from dirty sample homogenates. The complexities of the food matrix as well as the presence of particulate matter that may skew the results of conventional methods are not detrimental to the sensitivity and specificity of biosensors. She then demonstrated the use of a newly developed biosensor to detect Salmonella from spent sprout-irrigation water. Dr. Patricia Griffin lectured on the use of molecular techniques to type Salmonella isolates. Traditional Salmonella classification has been based on the characterization of the O and H antigens, known as serotyping. Serotyping is a tedious and time-consuming process. To take advantage of the simplicity of DNA technology, Dr. Griffin and her colleagues have developed specific probes based on the sequence of flagellar and O-antigen genes. Their goal is to develop probes for all of the common Salmonella serotypes in the United States. The applications of microarrays in the food industry was presented by Dr. Claude Mabilat. Microarrays (biochips) are extremely powerful tools to differentiate target organisms from backround flora. Advantages of biochips include great accuracy and robustness (redundancy). In the last lecture, Dr. Michael Brodsky presented the need for the accreditation and validation of analytical methods. Methods of analysis are extremely varied between laboratories and even within laboratories. Dr. Brodsky encourages the use of “fit for purpose” methods. The creation of eCAM (electronic compilation of analytical methods) will enable laboratories to select from a web-based list of proper methods.

S10 – Food Allergens: Past, Present and Future

Adriana Velasquez, University of Nebraska-Lincoln and Montserrat Hernandez, Universidad Autonoma de Queretaro

This session focused on the importance of food allergens and their impact on human health and the food industry. Susan L. Hefle from the University of Nebraska-Lincoln, mentioned that for sensitive individuals, the presence of allergens in food is potentially life threatening. Currently, there is no known cure for this sensitivity and the only successful method to manage allergic reactions is through avoidance of foods containing the allergen. Formulated foods, however, present a different challenge.

In such cases, the individual relies on accurate ingredient labeling. Dr. Kenneth Falci from FDA-CFSAN, emphasized the need to increase awareness of food allergens. He also mentioned that the major goal of the FDA-CFSAN is to provide guidance to industry and regulators on how to manage allergens through appropriate manufacturing and labeling practices. As part of these efforts, the FDA is conducting food allergen education programs for both consumers and industry employees. The agency also is developing a strategy for clear, easy-to-understand labeling of food allergens.

FDA-CFSAN awareness efforts currently focus on the eight foods that are most frequently implicated in serious allergic responses: milk, eggs, fish, wheat, tree nuts, legumes (particularly, peanuts and soybeans), crustaceans and mollusks. Allergenic proteins in these eight foods are estimated to cause 90% of the allergic reactions in the US Some of these foods, such as milk and eggs, are often used as ingredients in formulated products. Dr. Jupiter Yeung from NFPA mentioned that a number of test kits are manufactured in the US for commercial use and there are some other kits under development. Although there is not a test kit for each allergen in the food supply, kits are available for peanut, milk and egg protein. Although plans include standard development for other allergenic proteins, much work is needed to achieve this goal.

Bob Richardson, from General Mills, discussed the importance of sanitary design related to food allergens. He suggested the use of parallel modules to ensure the isolation and careful control of the path of allergenic ingredients when present in the plant. Also, as in all other food safety scenarios, training of engineers and employees is highly recommended.

Mark Moorman from W.K. Kellogg mentioned that the highest incidence of food allergenic reactions occur in children. He mentioned that the most common reasons for product recalls are incorrect ingredient statements, mixed foods, and/or inadequate allergen sanitation in the plant. The type, concentration, and form of the allergen are some of the determining factors in the sanitation of food plants to ensure the prevention of contamination.

Sheila Cohn from the National Restaurant Association reviewed the facts related to food allergens and the food service industry. She mentioned and suggested the use of the existing Food Allergy Training Guide, an already available resource for food establishments. The Food Allergy Initiative and Anaphylaxis Network created this set of guidelines in 2001. She also explained that the possibility of cross contamination is very unlikely to be completely eliminated in some restaurants due to multiple uses of utensils. As a consequence, special menu labeling could actually lead to a false sense of security by consumers since the lack of allergenic agents cannot be completely guaranteed.

S11 – Costs of Industry and Government Food Safety Actions: What is at Stake?

John Allen, University of Georgia and Justin R. Ransom, Colorado State University

Amber Jessup (FDA-CFSAN) discussed how human costs from foodborne illness are derived. These costs include loss of productivity, medical costs, etc. To determine the value of a life there are several approaches that can be used. A Hedonic approach can be used to determine how much people are willing to pay for a safety measure (e.g. irradiation of ground beef) to be put in place knowing that it could prevent illness or even death. The “Quality Adjusted Life Years” method places increased value on younger individuals due to the future years of productivity remaining for them.

Speaker Stan Bailey (USDA-ARS) presented costs associated with on-farm intervention strategies to reduce pathogen contamination. Some of these costs include: vaccines, facility improvements, monitoring programs, increased personnel, and sanitation and cleaning procedures. Producers also must factor in the costs of not performing certain interventions as well, which requires risk analysis and management strategies. Interventions can also provide certain cost savings related to prevented recalls, litigation, and bad publicity. Initiating interventions must require complete management commitment.

Larry Cohen (Kraft Foods) discussed the costs of in-plant interventions. These costs include sanitation, equipment/facility design, and personnel training. Deciding when and how thoroughly to perform plant sanitation protocols can control some of these costs. For instance, intensified deep cleaning of the environment and equipment with complete shutdown of production might only be performed every few weeks with a less intense cleaning daily or weekly—of course this would vary from plant to plant. Regulatory enforcement can lead to increased costs as well (i.e., a positive Listeria monocytogenes result requiring intervention).

Lori Ledenback (Kraft Foods) compared costs associated with in-house versus contract laboratory testing. Factors to consider include: overhead, labor, shipping of specimens, and the cost of obtaining results. To maintain the quality of results, proficiency samples are needed which require oversight and review. Audits can be done internally or through contracting with an outside reviewer. But, impartiality in conducting audits must be strictly adhered to. Flexibility in testing should be considered as well as certain times of the year may be busier than others and require higher turnaround time of lab results.

Phil Spinelli (USDA-FSIS) presented on the federal mandate requiring that government agencies must show the costs associated with new food regulations before being able to implement them. An economic assessment is required in order to identify where the market is failing to control a certain risk and then to aid in developing regulation to correct the failure. Also, an assessment is used to gather information about the economic impact of a regulation on industry, society, and government. The economic assessment consists of identifying the baseline level of a certain risk and then determining how it will change with new regulation.

Jenny Scott (NFPA) spoke about the costs of intervention versus recalls from the industry perspective. Market forces, food regulations, and liability laws drive the industry to pay the costs associated with intervention strategies (e.g. packaging, testing, environmental control, holding product during testing, etc.). The costs recalls are both direct and indirect. Direct costs include loss of product, cost of handling recalled product, wasted labor time, and other operational costs. Indirect costs include damage to brand reputation, decrease in stock value, and litigation expenses. A company must therefore weigh the financial costs/benefits associated with deciding to implement an intervention to determine what approach best suits the future needs of the company. 

S12 – Spoilage and Pathogenic Fungi and Yeasts

Megan Hereford, Virginia Tech and Angela Hartman, Virginia Tech

Ailsa Hocking spoke about ochratoxin, a kidney toxin that is formed by unrelated species of Aspergillus ochreus, Penicillium verrucosum, Aspergillus carbonarius and Aspergillus niger. While most isolates from A. ochreus do not produce toxin, the majority of isolates of A. carbonarius and A. niger form varied levels of ochratoxin, and isolates of P. verrucosum may produce the major source of Ochratoxin A. While fungicides are ineffective, rapid drying is probably the most effective control and milling reduces ochratoxin by 30–60%. Due to ochratoxin production and spoilage by fungi, Maribeth Cousin stated that there is a need to identify fungi, detect mycotoxin producers, use online monitoring, and use detection for biosecurity concerns. Rapid methods such as flow cytometry, detection of acids, enzymes, or volatiles produced by the fungi, or immunological methods such as fluorescent microscopy, ELISA, and latex agglutination are commonly used for general fungal detection, detection of specific genus/species, or for mycotoxin producers.

Larry Beuchat spoke about metabiotic associations of fungi and foodborne pathogens. A metabiotic association occurs when the growth of one or more microbes causes an environmental change that favors the growth of the other microbe. It has been shown that spoilage molds in tomatoes are capable of raising the pH so that Clostridium botulinum can grow and produce toxin. It was also shown that 20.2% of healthy portions, 26.4 % of decayed portions, and 67% of Alternaria spoiled portions of fruit and vegetables were found to contain Salmonella.

Lloyd Bullerman spoke of the economic impact and control of Fungi and mycotoxins in food. The presence of fungi in food can lead to significant costs for food producers. Approximately 5 to 10% of the world food supply is lost annually due to the presence of fungi and mycotoxins, and FAO estimates that about 25% of the world’s food crops are affected by fungi. The total yearly cost in the US is estimated in the hundreds of millions to billions. The most common fungi found in foods are Aspergillus spp. that cause losses in corn, peanuts, and cottonseeds, among others. This organism has a worldwide occurrence. Fusarium, which produces fumonisins, causes losses in corn and corn products and is found in all corn growing regions. Ochratoxin produced by Aspergillus and Penicillum spp. effects wheat, barley, green coffee, raisins, wine and beer.

Deepak Bhatnagar spoke of another problem caused by fungi, the production of aflatoxin in foods, which can occur pre or post harvest. This toxin has been shown to cause cancer in humans and animals, and aflatoxin B1 shows acute toxicity. The three lines of defense against aflatoxin are: preventing toxigenic fungus from getting to the crop; preventing the toxigenic fungus from invading the crop; and controlling toxin formation if it enters the plant. The proposed solution for achieving these three goals is genomics.

Dr. Stanley Brul spoke of use of genomics to develop novel antifungals for food use. He noted that fungi might be utilized for production of value added components in food, as well as it can spoil food or produce toxic compounds. Through use of genomics, spoilage in products may be prevented, making fungus more sensitive to preservatives, both natural and added.

S13 – Assuring Food Safety and Security

Sally Foong, Iowa State University and Angela Hartman, Virginia Tech

Overall strategy for FDA is awareness, prevention, protection, response, and recovery. Threat assessment models are based upon the Battelle Study, FDA-CFSAN Assessment Tools, IFT Task Order, and intelligence gathering. Critical needs for analytical methods (screening the fields and laboratories) are from sampling, behavior in foods, and validation of methods. Rapid detection can be carried out using lateral flow devices, biosensors, molecular methods, ELISA, LC-MS, GC-MS, g-ray detectors, and a or b detectors. Product security systems include product authentication (overt, covert, or forensic); tamper evidence (labels, tapes, seals); and trace and tracking systems (digital, barcodes, and electronic codes). Recovery systems validate disinfectant, decontaminate production areas, involve factors influencing disinfectant, and validation. Laboratory networks include FERN (Food Emergency Response Network).

Food safety is an issue of accidental or natural occurrence. Food security is an intentional threat, which involves personnel, product, and property. An increase in screening and supervision of the human element is needed. Risk assessment matrix is used to deal with food security risks. Currently, there is a need to assess or evaluate current practices, to identify weaknesses, and to implement controls. The NFPA assists the industry by implementing the 3 “Ls” which are “Light it, lock it, and limit access”. Better communication network; better secure information sharing, collaboration, cooperation, and coordination through intelligence, threat assessments, vulnerability assessments, and rankings; laboratory capacity and competency; and tools (both scientific and behavioral) are important in assuring food safety/security.

Livestock operations are possible weapons of mass destruction. “B-NICE” is the acronym for biological (zoonotics), nuclear, incendiary, chemical, and explosives as other methods of destruction. Transportation and distribution of livestock is the key. Assessment of terrorism threats is based on intent, capability, and vulnerability in determining when the threats are credible. North Carolina Homeland Security Initiatives include task forces, teams, and training programs or exercises. Food security issues involve public-private partnerships, role of physicians and medical examiners, rapid detection and accurate patient history, state and federal laboratories, surveillance in-plant and on farm, access to retail or food business or customer database, and industry staff food security training. Transportation security issues include trucks, loads, bulks; distribution; and drivers’ background checks.

Homeland Security is to protect the food supply in the United States. Terrorists can exploit multiple pathways in terms of weapons of mass destruction. Attacks on food supply other than being an easy target, cause sickness and death, disruption without deaths, and destroy brand names. Distinguishing between natural occurrence and intentional threat is difficult. The FSIS Directive Food Security Monitoring Procedure (Liberty Shield) enhances inspection activity, surveillance of in-distribution and import facilities, laboratory sampling for threat agents, and surveillance of human illnesses. Public Health Security and Bioterrorism protects the food supply by improving international meat inspection, recruitment from overseas in food production, and otherwise expand capacity to protect against the threat of bioterrorism. The FSIS Surveillance activities include consumer complaint monitoring systems, FoodNet, district veterinary medical specialists, epidemiology officers, regulating sampling data, and CDC.

S14 – Applied Microbiological Genomics for Food Safety and Quality

Laura Baurmiester, Auburn University and David Rasmussen, University of Tennessee

Dr. Stanley Brul of the University of Amsterdam and the Unilever Research group opened the session with the topic, “The Challenge of Genomics in Food Microbiology”. Also presented was a history of genetic advancements, milestones, ranging from 1859 to the present, noting the rapid change in our understanding of molecular structures and how 200–300 microbial genomes are know currently.

Dr. Brul next addressed the issue of biomarkers and their significance in the medical field, as well as potential use in the food industry. Biomarkers were noted for being useful for elucidating the effects of processing, identifying desirable fermentation traits, as well as discovering gene functions and cellular mechanisms.

Micro-arrays are an alternative to PCR, which can only look at one biomarker at a time, for the simultaneous examination of the expression of an organism’s entire genome under specified conditions. Different production methodologies for probe manufacturing were explained, comparing oligonucleotide synthesis verses pre-fabricated spotted arrays, with the pre-fabricated arrays being cheaper, yet having lower specificity than the synthesized probes.

Finally, an example of the application of micro-array technology was provided by a discussion of predictive behavior of Bacillus subtilis based upon gene expression during sporulation. Differences between a wild type strain and a heat resistant endospore in the presence of metals or minerals were detected by micro-array technology, otherwise known as “transcriptomics”.

The second speaker, Dr. Servé Notermans of the TNO Nutrition and Food Research Institute (in The Netherlands), provided the next seminar, “Predictive Microbiology based on Genomics: exploring a new technology.” After a brief history of microbiology was given, genomics was defined as the analysis of (genetic) patterns by pattern recognition via multivariate analysis. Micro-array technology was again for the focus of the discussion. Micro-arrays were derived from dot-blot hybridization, being spotted arrays of an organisms genome made available through high-throughput PCR amplification, yet now having 40,000 gene probes able to be spotted on each slide.

Dr. Notermans discussed how the bacterium can act as a sensor, exhibiting variable gene expression depending upon the conditions the bacterium is exposed to. RNA expression is tested for after a bacterium is grown in different growth parameters, including temperature, pH, time, and water activity. Repeated measurements of gene expression of a bacterium under various conditions then can provide a database of gene expression patterns at those different conditions. Micro-array technology may then be predictive for gene expression at a given set of conditions for a specific bacterium upon comparison of the databank for the specific microbe. Genomics (transcriptomics) therefore is an excellent tool for the access of emerging capacity of a microbe.

Dr. Paul Takhistov of Rutgers University provided the final discussion of the afternoon, “Cell-based Assay and Biosensors as the New Tools for the Detection and Qualification in Food Microbiology.” Biosensors are devices that incorporate a biological sensing element connected to a transducer. BioMEMS detectors were discussed followed by a three types of tranducers: optical, electrical/electrochemical, mechanical. Dr. Takhistov discussed the advantage of BioMEMS over micro-arrays, as it provides continual monitoring capabilities. Flow cytometry and Nano-patterned Gold Surface were also discussed. Dr. Takhistov noted the advantages of having real-time sensors and the robustness of cell based assay sensors. Also discussed were numerous technologies relating to cell-based assays and biosensors.

S15 – Campylobacter: A Pathogen in Need of Resolution

 Ethan Solomon, Rutgers University and Yohan Yoon, Colorado State University

This session focused on the pathogen Campylobacter. The speakers were ordered so that the audience was first given a background on the sources and ecology of the organism, then in-depth coverage of the difficulties associated with microbiological analysis and detection of Campylobacter. This was followed by a fascinating talk on the goals of the poultry industry regarding Campylobacter. Finally, the application of quantitative risk assessment to understanding the ecology of the organism and risk factors for human illness was presented. The order of the speakers did an excellent job of bringing out the true “farm to table” difficulties associated with this pathogen, and why any resolution is still seemingly out of reach.

Although Campylobacter is the most frequently reported agent of foodborne gastroenteritis, its importance has been understated compared to other organisms. The level of infection of Campylobacter has decreased 24% since 1996; however, the consumption of poultry products and raw milk as well as international travel continue to be associated with Campylobacter infection. The degree to which cross-contamination plays a role in infection is still unknown and is difficult to study using case-control. Also the level of person-to-person spread is unknown. These are areas requiring study in order to further reduce the level of Campylobacter. Dr. Eric Line discussed the difficulties associated with cultural methods for the detection of Campylobacter. Although more than 40 formulations for selective media for Campylobacter have been published, there is no standard methodology for the organism, further complicating intervention strategies. Contamination and low levels of target organisms hamper cultural methods for the detection of Campylobacter. Therefore, recently, new non-cultural methods have been put forth for the detection of Campylobacter. These methods may be extremely useful in understanding the ecology of the organism. The use of RT-PCR and its advantages over traditional PCR was also presented, detecting mRNA as an indicator of viable cells.  

In industry, risk assessment is necessary to characterize the ecology of the organism in order to devise better intervention strategies and reduce the incidence of human illness. A further need in the poultry industry is better carcass enumeration methods as well as the st