Source: COLORADO STATE UNIVERSITY submitted to
UNDERSTANDING AND CONTROLLING LISTERIA MONOCYTOGENES TRANSMISSION THROUGH READY-TO-EAT MEAT PRODUCTS FROM PROCESSING PLANT TO CONSUMER
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0203989
Grant No.
2005-51110-03278
Project No.
COL0-2005-02111
Proposal No.
2005-02111
Multistate No.
(N/A)
Program Code
111
Project Start Date
Sep 15, 2005
Project End Date
Aug 31, 2010
Grant Year
2005
Project Director
Sofos, J. N.
Recipient Organization
COLORADO STATE UNIVERSITY
(N/A)
FORT COLLINS,CO 80523
Performing Department
ANIMAL SCIENCE
Non Technical Summary
An estimated 2,493 cases of listeriosis and 499 deaths occur annually in the US. Listeria monocytogenes, the causative agent of this infection, is present in food processing environments and may contaminate ready-to-eat (RTE) meat and poultry products and other foods. In addition, this causative agent of meningitis, abortions and stillbirths, has the ability to survive and multiply in adverse environments, such as under refrigeration. The research, education and outreach activities of this multidisciplinary group of scientists from several institutions and states aim to identify ways to reduce the risk of listeriosis associated with consumption of RTE meat and poultry products. The target audience includes those involved in the RTE meat product continuum, such as processing, retail and foodservice industries, extension personnel, and consumer/health care providers. Expected outcomes include educational manuals, computer programs for modeling, pamphlets and electronic training materials with comprehensive approaches for L. monocytogenes control in RTE meats.
Animal Health Component
45%
Research Effort Categories
Basic
15%
Applied
45%
Developmental
40%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
5044010302015%
5045010302020%
7124010110045%
7125010302020%
Goals / Objectives
Contamination of ready-to-eat (RTE) meat and poultry products with Listeria monocytogenes appears to be predominantly due to post-processing contamination from food system associated environments (e.g., at the processing plant, at retail, in consumer homes) or due to cross-contamination. Major outbreaks, including fatalities, that have been associated with consumption of RTE meat and poultry products in recent years, have led to initiatives undertaken by regulatory authorities and the meat industry in an effort to control L. monocytogenes presence, survival and growth in RTE products. While these efforts may have reduced the incidence of listeriosis over the last few years, considerable additional efforts are needed to further reduce L. monocytogenes transmission. The goals of this multidisciplinary, collaborative effort, among scientists from several institutions and states, include research, education and outreach components aimed at reducing the risk of RTE meat and poultry products associated listeriosis, by intervening at the processing, foodservice, and consumer level. The proposed research, education and outreach activities will complement and extend the recent Food and Drug Administration/US Department of Agriculture (FDA/USDA) L. monocytogenes risk assessment and the new US Department of Agriculture Food Safety and Inspection Service (USDA-FSIS) L. monocytogenes control final rule, to achieve continued control of the risk of listeriosis associated with consumption of RTE meats. The goals will be accomplished through the following objectives: (1) understanding and controlling L. monocytogenes transmission at processing, where the overall goal is to define, develop, and communicate the most effective (cost vs. risk reduction) L. monocytogenes control strategies for RTE meat and poultry processors; (2) understanding and controlling L. monocytogenes transmission at foodservice and retail, where the overall goal is to define, develop, and communicate the most effective L. monocytogenes risk reduction strategies for RTE meat and poultry at retail/foodservice; (3) understanding and controlling L. monocytogenes transmission at the consumer level, where the overall goal is to define, develop, and communicate the most effective and applicable L. monocytogenes risk reduction strategies at this level of the food chain; (4) food systems analysis, where the overall goal is to develop a mathematical model of L. monocytogenes transmission from RTE processing plants to consumers in order to allow improved prediction of effective intervention strategies with regard to overall risk reduction; (5) economics of L. monocytogenes control strategies throughout the RTE meat and poultry food system, where the overall goal is to develop a comprehensive analysis of the costs and feasibility of selected L. monocytogenes control alternatives; and, (6) undergraduate and graduate teaching, where the overall goal is to train students with the expertise in Listeria control strategies from processing plant to consumer.
Project Methods
Execution of the project will start with the following initial activities: (1) a comprehensive review of the literature to update existing reviews as well as the FDA/USDA risk assessment at the time of initiation of the project; (2) an industry survey to determine current concerns, issues, practices, vulnerabilities and needs for Listeria control; (3) a foodservice and retail industry survey to determine current concerns, issues, practices, vulnerabilities and needs for Listeria control; (4) an extension outreach survey on current state of knowledge and practices of health care providers in advising those at risk of listeriosis; and, (5) a conference of 1.5 days to bring together interested stakeholders from the public health, academic, industry, and regulatory sectors to discuss the issues and to develop a best approach to address the objectives. These initial tasks will be followed by research, outreach and teaching activities to satisfy the outlined objectives, which will be accomplished by four core-units: (1) L. monocytogenes risks and controls in RTE meat and poultry products at the processing, distribution, retail, foodservice and consumer level; (2) genomics and molecular subtyping; (3) outreach and education; and, (4) mathematical modeling and economics. Standard detection and subtyping methods for L. monocytogenes and Listeria spp. will be used to test environmental and product samples from at least six processing establishments and 8-10 retail operations. Data will be used to analyze contamination patterns, to determine sources/spread and persistence of L. monocytogenes and Listeria spp., and to develop mathematical transmission models. Research efforts will also focus on evaluating the present USDA-FSIS strategy, as described in the final rule, of combining lethality and listeriostatic approaches with a particular emphasis on control of low levels of contamination, including resistance, injury, repair and outgrowth, and furthermore, refining the final rule options and alternative approaches to maximize listeriosis risk reduction. Outreach activities, through workshops and WWW-based training materials, will focus on training and communication of existing and new knowledge on the most effective L. monocytogenes risk reduction strategies to processors, retail and deli operators, and managers, and health inspectors. Furthermore, outreach activities will focus on educating high risk consumers and their health care or food service providers. In addition to the initial conference, at least one symposium at a national scientific meeting will be organized to present findings and recommendations of the work, upon completion of the project. The conference and symposium will be documented in proceedings available on CD and on appropriate web pages. The expected outcome of the above activities will be educational manuals, computer programs for modeling, pamphlets and electronic training materials with comprehensive approaches for L. monocytogenes control in RTE meat and poultry products, and they will target or have components applicable to processors, foodservice/retail operators of various sizes, and consumer/heath care providers.

Progress 09/15/05 to 08/31/10

Outputs
OUTPUTS: This collaborative project undertaken by scientists from five institutions included research, outreach, and education components aimed at reducing the risk of listeriosis by intervening at the processing, retail/foodservice, and consumer levels. A workshop of more than 70 stakeholder participants from the public health, academic, industry, and regulatory sectors contributed input to project objectives. Research activities addressed and provided knowledge on the prevalence/sources/transmission of Listeria monocytogenes in retail and small/very small meat processing environments, survival/growth of the pathogen on commercially-available ready-to-eat (RTE) meat products, antimicrobial controls that can be applied at the processing level, the effect of consumer practices (e.g., thawing and reheating) on survival of L. monocytogenes on RTE products; survival of the pathogen on food contact surfaces found in the home; and the effectiveness of commercially-available sanitizers for inactivation of L. monocytogenes biofilms. A revised quantitative risk assessment for L. monocytogenes in deli meats was developed that models the risk for three types of deli meats (ham, turkey, and roast beef), as well as L. monocytogenes contamination and growth from production to consumption while considering product-specific growth kinetics parameters; the model was also used to assess how reformulation of these deli meat categories with lactate-diacetate impacts the number of human listeriosis cases. Outreach education included: in-plant training of employees of five small/very small meat processing plants in three states; 20 webinars (39-381 participants), and at least 10 hands-on industry (12-34 attendees) and two train-the-trainer (20-23 attendees) workshops (held in conjunction with trade/scientific associations) on control of L. monocytogenes in RTE meat products; three webinars on "Promoting Safe Food Practices during Pregnancy, with Emphasis on Listeria" for 325 health professionals; 15 workshops in Colorado (219 seniors); 11 focus groups with child-bearing age (n=42) and senior (n=43) women in Colorado and Ohio on "Consumer Assessment of Safety and Date Labeling Statements on Ready-to-eat Meat and Poultry Products"; a nationwide web-based survey (269 dietary managers, 499 registered nurses or dietitians) to assess knowledge on L. monocytogenes, precautions taken to enhance food safety, and food safety training needs; development of a 3-minute web module designed to help pregnant women keep foods safe to eat; and symposia. Up to this point, the project has resulted in 25 peer-reviewed publications, two book chapters, 51 poster or oral presentations, five press releases, and several popular press articles, research reports, and invited presentations at national and international meetings. Participants trained, at least in part, include nine Ph.D. and nine M.S. students, seven postdocs/research associates, and seven visiting scientists. Results of research, outreach, and education activities will be valuable to regulators, industry, healthcare providers and advisors of susceptible human populations, and contribute to reduction of the incidence of listeriosis. PARTICIPANTS: Principal investigator: John N. Sofos (Colorado State University). Other Colorado State University investigators involved included Patricia A. Kendall, Kendra K. Nightingale, John A. Scanga, and Ifigenia Geornaras. Partner organizations and collaborators included: Martin Wiedmann (Cornell University), Harshavardhan Thippareddi (University of Nebraska-Lincoln), Lydia C. Medeiros (The Ohio State University), Elizabeth A.E. Boyle (Kansas State University), and Dennis Burson (University of Nebraska-Lincoln). Research associates, postdoctoral fellows, graduate and undergraduate students, and visiting scientists that have conducted research and/or were supported by the project: Khaled Abou-Zeid, Ioanna Barmpalia-Davis, Oleksandr Byelashov, Brandon Carlson, Serap Cosansu, Hristo Daskalov, Gianna Duran, Antonia Gounadaki, Camelia Grosulescu, Shivani Gupta, Renata Ivanek, Kyung Yuk Ko, Ukrit Laosiripornwattana, Yvan Le Marc, Jenna Lenhart, Alexandra Lianou, Galatios Moschonas, George-John Nychas, Sachi Parikh, Abani Pradhan, Mawill Rodriguez-Marval, Brian Sauders, Karl Schwab, Cangliang Shen, Catherine Simpson Beauchamp, Panagiotis Skandamis, Soula Tassou, Hanaa Thigeel, Alicia Valdez, Shanna Williams, Hua Yang, and Yohan Yoon. TARGET AUDIENCES: Audiences targeted were the ready-to-eat meat and poultry processing industry, especially small/very small processors, the retail industry, healthcare providers, seniors, pregnant women, other scientists, extension personnel, and regulatory agencies. Data were presented at various national and international conferences. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Foodborne illness due to Listeria monocytogenes does not occur frequently (2,493 estimated cases per year) in the United States; however, when it occurs, 20-30 percent of the cases result in death (499 per year). Pregnant women and their fetuses, the elderly, and individuals with suppressed immune systems are at increased risk for infection. A large number of listeriosis cases have been linked to consumption of ready-to-eat (RTE) meat products, and specifically, deli meats and frankfurters have been involved in multistate outbreaks and large-volume product recalls in the United States. The presence of L. monocytogenes on RTE meat products is primarily due to re-contamination or cross-contamination from equipment and/or environmental sources during processes that follow product cooking (e.g., slicing and re-packaging). Control of the pathogen is difficult because it is able to persist in processing environments for long periods of time, and is able to grow at refrigeration temperatures. This multi-component project, encompassing research, education, and outreach activities, and involving scientists from several institutions and states, was aimed at reducing the risk of L. monocytogenes from production to consumption. Research activities completed under this project have provided knowledge on the prevalence, diversity, and ecology of L. monocytogenes in environments of small/very small meat processing plants and retail establishments; survival/growth kinetics (lag time and growth rate) of the pathogen on 26 commercial RTE meat products (formulated without or with lactate-diacetate) from various companies; antimicrobial ingredients (existing and novel) that can be included in product formulations or be applied to products post-processing to inactivate or inhibit growth of L. monocytogenes; and consumer practices (e.g., microwave oven or stove-top reheating of frankfurters, and sanitation of food contact surfaces) that can reduce the risk of L. monocytogenes infection in the home. The pathogen survival/growth kinetics data collected from the commercially-available RTE meat products were used to develop models to predict pathogen populations in various RTE meat products as a function of product type, antimicrobials, storage temperature and time, and were also used to develop a revised quantitative risk assessment for L. monocytogenes in deli meats. Outreach and education activities included in-plant training for meat processors, hands-on and train-the-trainer workshops, and webinars targeted at industry personnel for controlling L. monocytogenes in RTE meat products. Workshops and webinars targeted at health professionals, seniors and pregnant women addressed ways to reduce the risk of listeriosis in high-risk population groups. Overall, the results of research studies and outreach activities under this project will be valuable to risk assessors for updating risk assessments, the meat industry and regulators in their efforts to implement strategies to control the pathogen in RTE meat products, and health professionals/providers, advisors of susceptible human populations, and consumers in their efforts to reduce the incidence of listeriosis.

Publications

  • Shen, C. 2010. Control of Escherichia coli O157:H7 and Listeria monocytogenes in meat and poultry products with chemicals and heating treatments. Ph.D. Dissertation, Department of Animal Sciences, Colorado State University, Fort Collins, CO.
  • Simpson Beauchamp, C. 2010. Growth and control of Escherichia coli O157:H7 in processing environments and fresh beef products and of Listeria monocytogenes on processed meats during home storage and thawing. Ph.D. Dissertation, Department of Animal Sciences, Colorado State University, Fort Collins, CO.
  • Byelashov, O.A., Daskalov, H., Geornaras, I., Kendall, P.A., Belk, K.E., Scanga, J.A., Smith, G.C., and Sofos, J.N. 2010. Reduction of Listeria monocytogenes on frankfurters treated with lactic acid solutions of various temperatures. Food Microbiol. 27:783-790.
  • Cosansu, S., Geornaras, I., Ayhan, K., and Sofos, J.N. 2010. Control of Listeria monocytogenes by bacteriocin-producing Pediococcus acidilactici 13 and its antimicrobial substance in a dry fermented sausage sucuk and in turkey breast. J. Food Nutrit. Res. 49:206-214.
  • Pradhan, A.K., Ivanek, R., Grohn, Y.T., Bukowski, R., Geornaras, I., Sofos, J.N., and Wiedmann, M. 2010. Quantitative risk assessment of listeriosis-associated deaths due to Listeria monocytogenes contamination of deli meats originating from manufacture and retail. J. Food Prot. 73:620-630.
  • Rodriguez-Marval, M., Kendall, P.A., Belk, K.E., and Sofos, J.N. 2010. Inactivation of Listeria monocytogenes during reheating of frankfurters with hot water before consumption. Food Prot. Trends 30:16-24.
  • Sauders, B.D., Sanchez, M.D., Rice, D.H., Corby, J., Stich, S., Fortes, E.D., Roof, S.E., and Wiedmann, M. 2009. Prevalence and molecular diversity of Listeria monocytogenes in retail establishments. J. Food Prot. 72:2337-2349.
  • Simpson Beauchamp, C., Byelashov, O.A., Geornaras, I., Kendall, P.A., Scanga, J.A., Belk, K.E., Smith, G.C., and Sofos, J.N. 2010. Fate of Listeria monocytogenes during freezing, thawing and home storage of frankfurters. Food Microbiol. 27:144-149.
  • Sofos, J.N. 2010. Multiple antimicrobial hurdle issues. Proceedings of the XVII Congreso Nacional de Microbiologia de los Alimentos, September 19-22, Valladolid, Spain, p. 17-19.
  • Buffer, J.L., Medeiros, L.C., Kendall, P.A., and Sofos, J. 2009. Dietitians are not consistently providing food safety education to at-risk populations. 2009 ADA Food & Nutrition Conference & Expo, October 17-20, Denver, CO. Abstract.
  • Chorianopoulos, N., Giaouris, S., Skandamis, P., Sofos, J., and Nychas, G. 2010. Effect of Listeria monocytogenes acid-tolerance response on its adherent survival under food processing-related stresses and on the subsequent disinfection of attached cells with standard acid and natural sanitizers. 97th Annual Meeting of the International Association for Food Protection, August 1-4, Anaheim, CA. Abstract No. P1-59.
  • Sofos, J.N. 2009. Transferring research results to industry for hazard control. Presented at the 11th Congreso Internacional, Inocuidad de Alimentos, XXVI Reunion Nacional de Microbiologia, Higiene y Toxicologia de los Alimentos, November 5-7, Puerto Vallarta, Jalisco, Mexico.
  • Sofos, J.N. 2009. Intervention strategies to control foodborne pathogens. Presented at the Asia Pacific Symposium on Food Safety 2009; hosted by the Korea Food and Drug Administration, and organized by the Korean Society of Food Hygiene and Safety, and Korean International Association for Food Protection Affiliate, November 11-13, Seoul, Korea.
  • Sofos, J.N. 2010. Overview of current meat hygiene and safety risks and summary of recent studies on biofilms, and control of Escherichia coli O157:H7 in nonintact, and Listeria monocytogenes in ready-to-eat, meat products. Presented at the 56th International Congress of Meat Science and Technology, August 15-20, Jeju, Korea.
  • Sofos, J.N. 2010. Food safety collaboration among academic, government and industry. Presented at the China International Food Safety & Quality Conference & Expo 2010, November 10-11, Shanghai, China.
  • Wiedmann, M. 2009. Listeria monocytogenes at the retail: from public health impact to transmission. Presented at the Arkansas Association for Food Protection Annual Meeting and Symposium, October 8-9, 2009, Tyson Foods headquarters, Springdale, AR.
  • Wiedmann, M. 2009. Listeria monocytogenes - it exists virtually everywhere, but how do we effectively find and control it Presented at the Maple Leaf Foods Food Safety Symposium - "Enhancing our Food Safety Knowledge and Capabilities to Produce Safer Food", October 23, Mississauga, Ontario, Canada.
  • Wiedmann, M. 2009. Improving food safety: research needs. Presented at the 2009 Meat Industry Research Conference, October 27-28, Chicago, IL.
  • Ivanek, R., Grohn, Y.T., Wiedmann, M., and Wells, M.T. 2009. Modeling Listeria monocytogenes cross-contamination dynamics within a quantitative risk assessment. Society for Risk Analysis Annual Meeting, December 6-9, Baltimore, MD. Abstract No. T3-F.3.
  • Kendall, P., Baker, S., Scharff, R., LeJeune, J., Sofos, J., and Medeiros, L. 2010. Impact of education on food safety knowledge and behavior of low-income English- and Spanish-speaking pregnant women. 2010 Food Safety Education Conference, March 23-26, Atlanta, GA. Abstract.
  • Pradhan, A.K., Ivanek, R., Grohn, Y.T., Bukowski, R., Geornaras, I., Sofos, J., and Wiedmann, M. 2009. Quantitative risk assessment on the effect of Listeria monocytogenes contamination in deli meats originating from manufacture and retail, on listeriosis cases. Society for Risk Analysis Annual Meeting, December 6-9, Baltimore, MD. Abstract No. P.86.
  • Skandamis, P.N., Gounadaki, A.S., Geornaras, I., and Sofos, J.N. 2010. Effect of planktonic and immobilized growth on the adaptive acid tolerance response of Listeria monocytogenes strains. 97th Annual Meeting of the International Association for Food Protection, August 1-4, Anaheim, CA. Abstract No. P2-120.
  • Sofos, J.N., Geornaras, I., Kendall, P.A., and Medeiros, L.C. 2010. Approaches for control of Listeria monocytogenes in the home environment. 2010 Food Safety Education Conference, March 23-26, Atlanta, GA. Abstract.
  • Wiedmann, M. 2009. Use of molecular subtyping and surveillance data to support risk assessments for Listeria monocytogenes. Society for Risk Analysis Annual Meeting, December 6-9, Baltimore, MD. Abstract No. T2-F.2.
  • Buffer, J., Medeiros, L., Schroeder, M., Kendall, P., LeJeune, J., and Sofos, J. 2010. Cleaning & sanitizing the kitchen using inexpensive household food-safe products. Factsheet.


Progress 09/15/08 to 09/14/09

Outputs
OUTPUTS: Scientists from five institutions and states are involved in this project, which includes research, outreach and education components aimed at reducing the risk of listeriosis by intervening at the processing, retail/foodservice, and consumer levels. A few of the accomplishments include: Identification of parameters (power level and time) for reheating of frankfurters in a microwave oven for inactivation of Listeria monocytogenes at the consumer level. Also, survival of the pathogen on food contact surfaces found in the home, and the effectiveness of commercially-available sanitizers for inactivation of L. monocytogenes biofilms was assessed. Year-2 of a longitudinal study of five small/very small meat processing plants in three states, to evaluate sources/transmission of L. monocytogenes has been completed. Overall, L. monocytogenes was isolated from 4.4 percent (range of 0 to 7.6 percent) of 896 samples (food contact and non-food contact surfaces, and finished products). In order to provide an improved quantitative risk assessment for L. monocytogenes in deli meats, a revised risk assessment was developed that models (i) the risk for three subcategories of deli meats (i.e., ham, turkey, and roast beef), and, (ii) L. monocytogenes contamination and growth from production to consumption while considering product-specific growth kinetics parameters (i.e., lag phase and exponential growth rate). The model was also used to assess how reformulation of these deli meat categories with antimicrobials (i.e., lactate-diacetate) impacts the number of human listeriosis cases. Results indicated that (i) various deli meat product types differ in their ability to support L. monocytogenes growth and their estimated per annum risk to human health; thus, they should be separated into different categories in a risk assessment, and, (ii) reformulation with antimicrobials reduces listeriosis cases by an estimated 2.5- to 7.8-fold; however, even with reformulation, deli meats would still cause a considerable number of illnesses. A webinar (381 participants; organized by www.meatingplace.com) and a 1-day hands-on live industry workshop (18 participants; The Ohio State University) was held. Topics covered in the webinar included an overview of the problem of L. monocytogenes contamination in ready-to-eat meat products, regulatory requirements, and physical and chemical interventions for pathogen control. A 3-minute web module designed to help pregnant women keep foods safe to eat was developed. The module, which contains information about listeriosis and ways to prevent it, offers advice on how to avoid foodborne illness during pregnancy, which foods are safe to eat, cleaning and food preparation tips, and how to safely store foods. Women who completed a post-module survey (98 respondents) found the module convenient and informative (93 percent strongly agreed/agreed). Most said they gained useful information from viewing the module (86 percent strongly agreed/agreed) and would recommend it to their friends (86 percent). They also said that they would be willing to watch more food safety related modules online (73 percent) or at their doctors' offices (94 percent). PARTICIPANTS: Principal investigator: John N. Sofos (Colorado State University). Other Colorado State University investigators involved include Patricia A. Kendall, Kendra K. Nightingale, and Ifigenia Geornaras. Partner organizations and collaborators include: Martin Wiedmann (Cornell University), Harshavardhan Thippareddi (University of Nebraska-Lincoln), Lydia C. Medeiros (The Ohio State University), Elizabeth A.E. Boyle (Kansas State University), and Dennis Burson (University of Nebraska-Lincoln). Research associates, postdoctoral fellows, and graduate and undergraduate students conducting research and/or supported by the project: Khaled Abou-Zeid, Oleksandr A. Byelashov, Antonia Gounadaki, Camelia Grosulescu, Renata Ivanek, Kyung Yuk Ko, Galatios Moschonas, Abani Pradhan, Karl Schwab, Cangliang Shen, Panagiotis Skandamis, Alicia C. Valdez and, Hua Yang. TARGET AUDIENCES: Audiences targeted were the ready-to-eat meat and poultry processing industry, especially small/very small processors, the retail industry, healthcare providers, seniors, pregnant women, other scientists, extension personnel, and regulatory agencies. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Listeriosis, the infection caused by Listeria monocytogenes, is rare among healthy individuals; however, it can lead to severe consequences, even death (20-30 percent fatality rate), in susceptible population groups including fetuses, neonates, the elderly, and individuals with weakened immune systems. Furthermore, listeriosis can result in miscarriages or stillbirths in pregnant women. Based on current estimates, there are 2,493 cases (99 percent of them foodborne) of listeriosis per year in the U.S., and of these, 499 result in death. Foodborne listeriosis is, thus, an important public health concern. Contamination and control of L. monocytogenes in foods is difficult due to the ubiquitous nature of the organism and its ability to grow under refrigeration temperatures. Ready-to-eat (RTE) meat and poultry products have been involved in fatal multistate listeriosis outbreaks and large-volume product recalls in the U.S. Although the cooking process that RTE meat products undergo kills bacterial pathogens, when properly applied, re-contamination or cross-contamination may accidentally be introduced during processes that follow cooking (e.g., slicing and re-packaging), from equipment and/or environmental sources. The infectious dose of L. monocytogenes is not known, and since, by definition, RTE meat products are intended to be consumed without further heating, contamination of such foods with even low levels of the pathogen, may result in illness or death in susceptible groups. Although regulatory requirements for RTE meat processors are in place to control L. monocytogenes presence and survival/growth on products, illnesses (mostly sporadic) and product recalls continue to occur. This multi-component project, encompassing research, education and outreach activities, and involving scientists from several institutions and states, is aimed at reducing the risk of listeriosis associated with consumption of RTE meat products. Target audiences include those involved with processing and retail/foodservice, and extension personnel, healthcare providers and consumers. Field and laboratory research activities evaluate transmission/sources of L. monocytogenes in small/very small processing and retail environments, its survival/growth potential on commercially-available RTE meat products, and chemical and/or physical treatments for its control at the production, distribution and consumption levels. Outreach and education activities include workshops and webinars targeted at industry personnel, extension agents, health professionals and high-risk consumers (e.g., seniors and pregnant women) for reducing the risk of listeriosis. A nationwide web-based needs assessment survey of 269 dietary managers, 267 registered dietitians and 232 registered nurses will help elucidate their knowledge of L. monocytogenes, food safety education provided to patients, precautions taken to enhance food safety (dietary managers), and food safety training needs. Results of research, outreach and education activities under this project are valuable to regulators, industry, healthcare providers and high-risk populations, and contribute to reduction of the incidence of listeriosis.

Publications

  • Williams, S.K., Roof, S., Boyle, E.A., Thippareddi, H., Burson, D.E., Nightingale, K.K., Wiedmann, M., and Sofos, J.N. 2009. Molecular detection of Listeria monocytogenes in small and very small ready-to-eat meat processing plants. 96th Annual Meeting of the International Association for Food Protection, July 12-15, Grapevine, TX. Abstract No. T8-08.
  • Mayer, K., Boyle, E., Burson, D., and Thippareddi, H. 2009. Validation documents for using antimicrobial agents in ready-to-eat meat and poultry products to control Listeria monocytogenes. Available at: http://www.ksre.ksu.edu/library/fntr2/ep152.pdf. Accessed 7 September, 2009.
  • Axman, T., Getty, K.J.K, Lobaton-Sulabo, A.S., Harper, N.M., and Boyle, E.A.E. 2009. Effect of packaging and storage time on survival of Listeria monocytogenes on shelf-stable whole muscle jerky. 14th Annual K-State Research Forum, Kansas State University, Manhattan, KS, March 6.
  • Medeiros, L. 2009. L. monocytogenes - Why should we care Consumer issues and perceptions. Presented at a workshop on Control of Listeria monocytogenes on Ready-to-Eat Meat and Poultry Products, July 21, The Ohio State University, Columbus, OH.
  • Thippareddi, H. 2009. Listeria monocytogenes: the organism, the issue and the need to control it in ready-to-eat meat and poultry processing environment and the RTE products. Presented at a special symposium organized by the Poultry and Pork Processor Associations in Chile, 23 January, Santiago, Chile.
  • Thippareddi, H. 2009. Listeria monocytogenes - The organism and its implications to RTE meat and poultry processors. Presented at a workshop on Control of Listeria monocytogenes on Ready-to-Eat Meat and Poultry Products, July 21, The Ohio State University, Columbus, OH.
  • Thippareddi, H. 2009. L. monocytogenes in RTE meats - Regulatory update. Presented at a workshop on Control of Listeria monocytogenes on Ready-to-Eat Meat and Poultry Products, July 21, The Ohio State University, Columbus, OH.
  • Thippareddi, H. 2009. Preparing for a food safety assessment - What can you do Presented at a workshop on Control of Listeria monocytogenes on Ready-to-Eat Meat and Poultry Products, July 21, The Ohio State University, Columbus, OH.
  • Thippareddi, H. 2009. Control of Listeria through sanitary equipment and facility design and sanitation best practices. Presented at a workshop on Control of Listeria monocytogenes on Ready-to-Eat Meat and Poultry Products, July 21, The Ohio State University, Columbus, OH.
  • Williams, S.K., Nightingale, K.K., Sofos, J.N., Scanga, J.A., Roof, S., Wiedmann, M., Thippareddi, H., Burson, D., and Boyle, E.A. 2009. Molecular ecology of Listeria in small and very small ready-to-eat meat processing plants. 109th General Meeting of the American Society for Microbiology, May 17-21, Philadelphia, PA. Abstract No. P-058.
  • Thippareddi, H. 2009. Data analysis, root cause identification and corrective actions. Presented at a workshop on Control of Listeria monocytogenes on Ready-to-Eat Meat and Poultry Products, July 21, The Ohio State University, Columbus, OH.
  • Thippareddi, H. 2009. Validation and verification of intervention strategies. Presented at a workshop on Control of Listeria monocytogenes on Ready-to-Eat Meat and Poultry Products, July 21, The Ohio State University, Columbus, OH.
  • Thippareddi, H. 2009. Listeria control: old problem, new solutions. Webinar on Keeping Listeria at Bay: the Battle that Ready-to-eat Processors Can't Afford to Lose, organized by www.meatingplace.com, September 9. Available at: http://www.meatingplace.com/Webinars/init.aspx. Accessed 9 September, 2009.
  • Wiedmann, M. 2009. L. monocytogenes at retail - subtype data and transmission. Meeting on Listeria monocytogenes in Retail Deli: Research and Risk Assessment, organized by FMI and JIFSAN, January 14, College Park, MD.
  • Wiedmann, M. 2009. New insight in the origin of Listeria monocytogenes in the retail environment. Meeting on Listeria monocytogenes in Retail Deli: Risk Assessment & Data Needs, February 5, Office of Public Health Science, Food Safety and Inspection Service, Washington, DC.
  • Wiedmann, M. 2009. Molecular studies on the transmission of the foodborne pathogen Listeria monocytogenes: from environmental persistence to human outbreaks. Invited Seminar, Illinois Institute of Technology and FDA NCFST (National Center for Food Safety and Technology), April 27.
  • Wiedmann, M. 2009. New insight in the origin of Listeria monocytogenes in the retail environment: Cornell University studies. Public meeting on the interagency retail Listeria monocytogenes risk assessment, June 23, Washington, DC.
  • Colorado State scientists work to control Listeria outbreak. 2008. Today@Colorado State (10/07/08), Colorado State University. Available at: http://www.today-archive.colostate.edu/index.aspurl=display_story&st ory_id=1005557. Accessed on 7 September, 2009.
  • Byelashov, O.A. 2009. Effects of brining ingredients and antimicrobials on thermal inactivation of Escherichia coli O157:H7 in a meat model system and control of Listeria monocytogenes in frankfurters. Ph.D. Dissertation, Department of Animal Sciences, Colorado State University, Fort Collins, CO.
  • Barmpalia-Davis, I.M., Geornaras, I., Kendall, P.A., and Sofos, J.N. 2009. Effect of fat content on survival of Listeria monocytogenes during simulated digestion of inoculated beef frankfurters stored at 7 degreesC. Food Microbiol. 26:483-490.
  • Byelashov, O.A., Carlson, B.A., Geornaras, I., Kendall, P.A., Scanga, J.A., and Sofos, J.N. 2009. Fate of post-processing inoculated Listeria monocytogenes on vacuum-packaged pepperoni stored at 4, 12 or 25 degreesC. Food Microbiol. 26:77-81.
  • Pradhan, A.K., Ivanek, R., Grohn, Y.T., Geornaras, I., Sofos, J.N., and Wiedmann, M. 2009. Quantitative risk assessment for Listeria monocytogenes in selected categories of deli meats: impact of lactate and diacetate on listeriosis cases and deaths. J. Food Prot. 72:978-989.
  • Rodriguez-Marval, M., Geornaras, I., Kendall, P.A., Scanga, J.A., Belk, K.E., and Sofos, J.N. 2009. Microwave oven heating for inactivation of Listeria monocytogenes on frankfurters before consumption. J. Food Sci.74:M453-M460.
  • Shen, C., Geornaras, I., Kendall, P.A., and Sofos, J.N. 2009. Control of Listeria monocytogenes on frankfurters by dipping in hops beta acids solutions. J. Food Prot. 72:702-706.
  • Shen, C., Geornaras, I., Kendall, P.A., and Sofos, J.N. 2009. Antilisterial activities of salad dressings, without or with prior microwave oven heating, on frankfurters during simulated home storage. Int. J. Food Microbiol. 132:9-13.
  • Skandamis, P.N., Stopforth, J.D., Yoon, Y., Kendall, P.A., and Sofos, J.N. 2009. Heat and acid tolerance responses of Listeria monocytogenes as affected by sequential exposure to hurdles during growth. J. Food Prot. 72:1412-1418.
  • Yang, H., Kendall, P.A., Medeiros, L.C., and Sofos, J.N. 2009. Efficacy of sanitizing agents against Listeria monocytogenes biofilms on high-density polyethylene cutting board surfaces. J. Food Prot. 72:990-998.
  • Yang, H., Kendall, P.A., Medeiros, L., and Sofos, J.N. 2009. Inactivation of Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella Typhimurium with compounds available in households. J. Food Prot. 72:1201-1208.
  • Cosansu, S., Geornaras, I., Ayhan, K., and Sofos, J.N. 2009. Control of Listeria monocytogenes on ready-to-eat turkey breast slices by bacteriocin. 3rd International Congress on Food and Nutrition, April 22-25, Antalya, Turkey. Abstract.
  • Geornaras, I., Grosulescu, C.C., Gupta, S., Le Marc, Y., Kendall, P.A., Baranyi, J., and Sofos, J.N. 2009. Growth of Listeria monocytogenes on three ham products formulated with and without potassium/sodium lactate and sodium diacetate. 96th Annual Meeting of the International Association for Food Protection, July 12-15, Grapevine, TX. Abstract No. P3-53.
  • Grosulescu, C.C., Geornaras, I., Laosiripornwattana, U., Le Marc, Y., Kendall, P.A., and Sofos, J.N. 2009. Growth kinetics of Listeria monocytogenes on cured and uncured turkey breast. 69th Annual Meeting of the Institute of Food Technologists, June 6-9, Anaheim/OC, CA. Abstract No. 155-25.
  • Gupta, S., Geornaras, I., Kendall, P.A., Medeiros, L.C., and Sofos, J.N. 2009. Survival and recovery of Listeria monocytogenes from laminate kitchen countertop surfaces with different cleaning materials. 69th Annual Meeting of the Institute of Food Technologists, June 6-9, Anaheim/OC, CA. Abstract No. 236-05.
  • Le Marc, Y., Geornaras, I., Baranyi, J., and Sofos, J.N. 2009. Modelling the kinetics of Listeria monocytogenes on frankfurters and other ready-to-eat meat products from manufacturing to consumption. 6th International Conference on Predictive Modeling in Foods, September 8-12, Washington, DC. Abstract.
  • Lobaton-Sulabo, A.S., Boyle, E.A.E., Getty, K.J.K., Axman, T., Uppal, K.K., Barry, B., and Higgins, J.J. 2009. Package systems and storage times serve as post-lethality treatments for Listeria monocytogenes on smoked sausage sticks. 62nd Reciprocal Meat Conference, American Meat Science Association, June 21-24, Rogers, AR. Abstract No. 34.
  • Lobaton-Sulabo, A.S., Axman, T., Getty, K.J.K., Boyle, E.A.E., Harper, N.M., Uppal, K.K., Barry, B., and Higgins, J.J. 2009. Packaging systems and storage times affect survival of Listeria monocytogenes on whole muscle beef jerky. 62nd Reciprocal Meat Conference, American Meat Science Association, June 21-24, Rogers, AR. Abstract No. 33.
  • Parikh, S., Kendall, P.A., Yang, H., Geornaras, I., and Sofos, J.N. 2009. Survival and inactivation of Listeria monocytogenes biofilms on food contact surfaces using commercially available and homemade sanitizers. 69th Annual Meeting of the Institute of Food Technologists, June 6-9, Anaheim/OC, CA. Abstract No. 123-38.
  • Parikh, S., Kendall, P.A., Yang, H., Geornaras, I., Medeiros, L.C., and Sofos, J.N. 2009. Efficiency of commonly available sanitizers and household compounds against Listeria monocytogenes biofilms on food contact surfaces with/without exposure to nutrients. 96th Annual Meeting of the International Association for Food Protection, July 12-15, Grapevine, TX. Abstract No. P2-63.
  • Lianou, A., and Sofos. J.N. 2009. Interventions for hazard control in retail-handled ready-to-eat foods, p. 411-435. In V.K. Juneja, and J.N. Sofos (ed.), Pathogens and toxins in foods: challenges and interventions, ASM Press, Washington, DC. ISBN: 978-1-55581-459-5.
  • Simpson, C.A., and Sofos, J.N. 2009. Antimicrobial ingredients, p. 301-377. In R. Tarte (ed.), Ingredients in meat products: properties, functionality and applications, Springer Science+Business Media, New York, NY. ISBN: 978-0-387-71326-7.
  • Byelashov, O.A., Geornaras, I., Grosulescu, C.C., Nightingale, K.K., Kendall, P.A., and Sofos, J.N. 2009. Growth of Listeria monocytogenes on sliced inoculated pastrami and roast beef during vacuum-packaged storage at 4, 7 or 12 degreesC. 96th Annual Meeting of the International Association for Food Protection, July 12-15, Grapevine, TX. Abstract No. P1-23.
  • Pradhan A., Ivanek, R., Grohn, Y.T., Geornaras, I., Sofos, J., and Wiedmann, M. 2008. Quantitative risk assessment for Listeria monocytogenes in selected categories of deli meats: impact of lactate-diacetate on listeriosis cases. Society for Risk Analysis Annual Meeting, December 7-10, Boston, MA. Abstract No. P121.
  • Shen, C., Geornaras, I., Kendall, P.A., and Sofos, J.N. 2009. Survival of Listeria monocytogenes on diced ham and turkey breast treated with salad dressings without or with prior microwave oven heating. 69th Annual Meeting of the Institute of Food Technologists, June 6-9, Anaheim/OC, CA. Abstract No. 123-52.
  • Sofos, J.N., Wiedmann, M., and Thippareddi, H. 2009. Understanding and controlling Listeria monocytogenes transmission through ready-to-eat meat products from processing plant to consumer. 2009 Project Directors Meeting for the National Integrated Food Safety Initiative, USDA-CSREES, July 11, Grapevine, TX. Abstract.
  • Uppal, K.K., Lobaton-Sulabo, A.S., Getty, K.J., Barry, B., and Boyle, E.A.E. 2009. Effect of packaging and storage time on survival of Listeria monocytogenes on shelf-stable meat snacks. 69th Annual Meeting of the Institute of Food Technologists, June 6-9, Anaheim/OC, CA. Abstract No. 155-06.


Progress 09/15/07 to 09/14/08

Outputs
OUTPUTS: This collaborative project includes research, outreach and education components aimed at reducing the risk of listeriosis by intervening at the processing, retail/foodservice, and consumer levels. A few of the accomplishments include: A cross-sectional study, in collaboration with the New York State Department of Agriculture and Markets, on transmission/sources of Listeria monocytogenes in retail environments of 60 small/very small establishments and 60 establishments with low inspection scores showed 13.1 and 13.2 percent, respectively, of environmental samples as positive for the pathogen. Data from six small/very small processing plants in three states indicated persistence of specific Listeria strains in at least three plants. Previously collected data were used to develop and conduct in-plant training of employees on controlling L. monocytogenes. Ten web seminars were conducted, with two talks per session, with the purpose of disseminating information to assist small and very small processors. Topics covered included regulations pertaining to L. monocytogenes, a description of the characteristics of the organism, methods for its control in the product and environment, sampling plans, and methods of detection. Approximately 23, 63 and 13 percent of the 420 participants were from very small, small and large processing operations, respectively. Most (greater than 90 percent) of the participants were from the U.S., while the others were from Canada, Mexico and Central/South America. A poll conducted at the end of each session showed that 98 percent of the participants found the sessions easy to follow, 89 percent strongly agreed/agreed that the sessions were useful and that they gained useful information, and more than 96 percent indicated that they had a better understanding of the topics discussed. A nationwide web-based survey of registered nurses (RN) and registered dietitians (RD) about educational practices related to food safety and L. monocytogenes, was also completed (N=499). About 66 and 82-87 percent of RN and RD, respectively, correctly identified pregnant women, the elderly and immune compromised patients as high-risk populations for listeriosis. The RN self-rated understanding of L. monocytogenes was very low/low (89.7 percent) in contrast to RD with much higher understanding (62.5 percent moderate/very high). Three 1.5 hr webinars and 5 live workshops on Preventing Listeriosis during Pregnancy were held with health professionals that work with pregnant women; 325 professionals from 45 states attended a webinar and 76 attended a workshop. Knowledge scores increased 22 and 32 percent in the webinars and workshops, respectively. As a result of the trainings, 65 percent of webinar and 92 percent of workshop participants planned to make changes in food safety recommendations and over 60 percent planned changes in the types of educational materials for pregnant women. A two-part symposium on Listeria monocytogenes Control in Ready-to-eat Meat and Poultry Products: Post-processing Issues was held at the annual meeting of the Institute of Food Technologists, where findings from the project were disseminated to a scientific audience. PARTICIPANTS: Principal investigator: John N. Sofos (Colorado State University). Other Colorado State University investigators involved include Patricia A. Kendall, Kendra Nightingale, and Ifigenia Geornaras. Partner organizations and collaborators include: Martin Wiedmann (Cornell University), Harshavardhan Thippareddi (University of Nebraska-Lincoln), Lydia Medeiros (Ohio State University), Elizabeth Boyle (Kansas State University), and Dennis Burson (University of Nebraska-Lincoln). TARGET AUDIENCES: Audiences targeted were the meat and poultry processing industry, especially small processors, the retail industry, registered nurses and registered dieticians who serve persons at high risk for foodborne illness, other scientists, extension personnel, and regulatory agencies. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Processed meat and poultry products intended to be consumed without further heating have being linked to fatal listeriosis outbreaks and product recalls in the U.S. The causative agent of listeriosis is Listeria monocytogenes, a ubiquitous microorganism that is able to survive and multiply under adverse conditions including refrigeration temperatures. Fortunately, infection with L. monocytogenes is not common, accounting for approximately 0.018 percent of illnesses (2,493 cases/year) in the U.S. due to known foodborne pathogens; however, it is associated with a high fatality rate (20-30 percent; 499 deaths/year) especially in susceptible populations groups, including the elderly, fetuses, neonates, and individuals with suppressed immune systems. The infectious dose of L. monocytogenes is not known, therefore contamination, even at low levels, of ready-to-eat meat and poultry products that have properties (ingredients, water activity, acidity) that will permit multiplication of the pathogen during distribution and retail storage before consumption cannot be tolerated. Contamination of such products occurs primarily from contaminated food processing equipment and other surfaces during processes that follow the cooking step, such as peeling, slicing, dicing, and re-packaging. Regulatory requirements for control of the pathogen in such products include the application of physical interventions and/or inclusion of L. monocytogenes growth inhibitors in product formulations to inactivate, and/or prevent or suppress growth of survivors during storage. This project is a collaborative effort among scientists from five institutions and includes research, outreach and education components aimed at reducing the risk of listeriosis by intervening at the processing, retail/foodservice, and consumer level. Laboratory and field research activities evaluate the potential for survival/growth of L. monocytogenes in ready-to-eat meat and poultry products, antimicrobial alternatives for control, and transmission/sources of the pathogen in processing and retail environments. Outreach and education activities encompass workshops, webinars and training of personnel, especially of small/very small processing facilities, and extension agents to serve in train-the-trainer activities, as well as health care providers and at-risk consumers for better control of the pathogen and avoidance of listeriosis. A nationwide web-based survey of health professionals (registered dieticians and registered nurses) and dietary managers who serve high-risk populations will help better understand their knowledge and awareness of L. monocytogenes, as well as their food safety training needs. The information gained from this survey will help in the development of training materials for health care providers to help minimize the risk of L. monocytogenes infection in establishments that serve high-risk populations. Overall, the results of research studies and outreach and education activities under this project will be valuable to regulatory agencies, the industry, health care providers and advisors of susceptible human populations in their efforts to reduce the incidence of listeriosis.

Publications

  • Laosiripornwattana, U. 2008. Listeria monocytogenes changes in commercial uncured turkey breast with or without sodium lactate and sodium diacetate. Master's thesis, Department of Food Science and Human Nutrition, Colorado State University.
  • Gupta, S., Kendall, P.A., Geornaras, I., and Sofos, J.N. 2008. Survival of Listeria monocytogenes on kitchen countertop laminate surfaces. Animal Sciences Research Report, Department of Animal Sciences, Colorado State University, Fort Collins, CO. 4 p.
  • Yuan, W. 2008. Registered nurses and registered dietitians lack awareness and knowledge of Listeria monocytogenes indicating need for continuing education. Master's thesis, Department of Human Nutrition, The Ohio State University.
  • Barmpalia-Davis, I.M., Geornaras, I., Kendall, P.A., and Sofos, J.N. 2008. Survival of Listeria monocytogenes in a simulated dynamic gastrointestinal model during storage of inoculated bologna and salami slices in vacuum packages. J. Food Prot. 71:2014-2023.
  • Byelashov, O.A., Kendall, P.A., Belk, K.E., Scanga, J.A., and Sofos, J.N. 2008. Control of Listeria monocytogenes on vacuum-packaged frankfurters sprayed with lactic acid alone or in combination with sodium lauryl sulfate. J. Food Prot. 71:728-734.
  • Lenhart, J., Kendall, P., Medeiros, L., Doorn, J., Schroeder, M., and Sofos, J. 2008. Consumer assessment of safety and date labeling statements on ready-to-eat meat and poultry products designed to minimize risk of listeriosis. J. Food Prot. 71:70-76.
  • Simpson, C.A., Geornaras, I., Yoon, Y., Scanga, J.A., Kendall, P.A., and Sofos, J.N. 2008. Effect of inoculum preparation procedure and storage time and temperature on the fate of Listeria monocytogenes on inoculated salami. J. Food Prot. 71:494-501.
  • Grohn, Y., Hertl, J., Ivanek, R., Abou-Zeid, K., and Wiedmann, M. 2007. How university researchers can contribute to farm-to-table risk assessments: Listeria monocytogenes as an example. Foodb. Path. Dis. 4:527-537.
  • Williams, S.K., Roof, S., Boyle, E.A., Thippareddi, H., Burson, D., Nightingale, K.K., Wiedmann, M., Scanga, J.A., and Sofos, J.N. 2008. A longitudinal study on Listeria monocytogenes contamination patterns in small and very small ready-to-eat meat processing plants. 108th General Meeting of the American Society for Microbiology, June 1-5, Boston, MA. Abstract No. P-067.
  • Duran, G., Geornaras, I., and Sofos, J.N. 2008. Antilisterial effects of a sequential carvacrol and acetic acid dip. 68th Annual Meeting of the Institute of Food Technologists, June 28-July 1, New Orleans, LA. Abstract No. 052-21.
  • Rodriguez-Marval, M., Kendall, P.A., Belk, K.E., and Sofos, J.N. 2008. Use of hot water for inactivation of Listeria monocytogenes inoculated on frankfurters formulated with or without antimicrobials. 68th Annual Meeting of the Institute of Food Technologists, June 28-July 1, New Orleans, LA. Abstract No. 052-23.
  • Sofos, J.N., and Geornaras, I. 2008. Advances in antimicrobial intervention strategies to control microbial contamination and future opportunities. 68th Annual Meeting of the Institute of Food Technologists, June 28-July 1, New Orleans, LA. Abstract No. 141-02.
  • Yang, H., Kendall, P.A., Medeiros, L.C., and Sofos, J.N. 2008. Efficacy of sanitizing agents for home use against Listeria monocytogenes biofilms on smooth and rough surface high density polyethylene cutting boards. 68th Annual Meeting of the Institute of Food Technologists, June 28-July 1, New Orleans, LA. Abstract No. 052-37.
  • Barmpalia-Davis, I.M., Geornaras, I., Kendall, P.A., and Sofos, J.N. 2008. Effect of fat content on survival of Listeria monocytogenes during simulated digestion of inoculated beef frankfurters stored at 7 degreesC. 95th Annual Meeting of the International Association for Food Protection, August 3-6, Columbus, OH. Abstract No. P2-56.
  • Buffer, J., Medeiros, L., Yuan, W., Kendall, P., and Sofos, J. 2008. When do dietitians and nurses provide food safety information to high risk populations 95th Annual Meeting of the International Association for Food Protection, August 3-6, Columbus, OH. Abstract No. P3-55.
  • Geornaras, I., Le Marc, Y., Yoon, Y., Barmpalia-Davis, I., Jha, A., Mora, M., Baranyi, J., and Sofos, J. 2008. Modelling the effect of temperature on the growth of Listeria monocytogenes on commercial beef bologna and frankfurters. FoodMicro 2008, the 21st International ICFMH Symposium, September 1-4, Aberdeen, Scotland. Abstract No. P C9.
  • Le Marc, Y., Geornaras, I., Barmpalia-Davis, I., Yoon, Y., Baranyi, J., and Sofos, J. 2008. Predicting the effects of temperature and background competitive flora on the growth of Listeria monocytogenes on commercial turkey frankfurters. FoodMicro 2008, the 21st International ICFMH Symposium, September 1-4, Aberdeen, Scotland. Abstract No. P C10.
  • Sofos, J.N. 2008. Listeria monocytogenes: enemy no. 1 for the ready-to-eat industry. National Provisioner February, 2 p.
  • Kendall, P., Medeiros, L., Schroeder, M., Yuan, W., and Sofos, J. 2008. Safe food practices of dietary managers at high risk for listeriosis. Dietary Manager 17(4):8-12.
  • Mayer, A.L., Gunderson, J.A., Lobaton-Sulabo, A.S., Boyle, E.A.E., Houser, T.A., and Higgins, J.J. 2008. Antimicrobial ingredients affect beef snack stick quality. Beef Cattle Research Report, Kansas State University. 3 p.
  • Sofos, J.N. 2008. Listeria monocytogenes control strategies: physical, chemical and combination treatments. Workshop on Control of Listeria monocytogenes on Ready-to Eat Meat and Poultry Products, Sponsored by National Association of Meat Processors and National Meat Association, April 23, Ontario, CA.
  • Sofos, J.N. 2008. Validation and verification of intervention strategies. Workshop on Control of Listeria monocytogenes on Ready-to Eat Meat and Poultry Products, Sponsored by National Association of Meat Processors and National Meat Association, April 23, Ontario, CA.
  • Sofos, J.N. 2008. Listeria monocytogenes: Issues and prevalence in ready-to-eat meat and poultry products at retail and at home. Presented at the 68th Annual Meeting of the Institute of Food Technologists, June 28-July 1, New Orleans, LA.
  • Sofos, J.N. 2008. Developments and future outlook for postharvest food safety. Presented at the Joint American Dairy Science Association-American Society of Animal Science Annual Meeting, July 7-11, Indianapolis, IN.
  • Sofos, J.N. 2008. Control of Listeria through sanitary equipment and facility design and sanitation best practices. Workshop on Control of Listeria monocytogenes on Ready-to Eat Meat and Poultry Products, Sponsored by National Association of Meat Processors and National Meat Association, April 23, Ontario, CA.
  • Duran, G., Geornaras, I., Engle, T.E., and Sofos, J.N. 2008. Membrane fatty acid changes of cells from ten Listeria monocytogenes strains exposed to various antimicrobials. 95th Annual Meeting of the International Association for Food Protection, August 3-6, Columbus, OH. Abstract No. P4-48.
  • Le Marc, Y., Geornaras, I., Carlson, B.A., Yoon, Y., Baranyi, J., and Sofos, J.N. 2008. Predicting the effects of storage temperature on growth of Listeria monocytogenes on roast beef formulated with or without antimicrobials. 95th Annual Meeting of the International Association for Food Protection, August 3-6, Columbus, OH. Abstract No. P5-29.
  • Kendall, P., Medeiros, L., Schroeder, M., Yuan, W., and Sofos, J. 2008. Food safety practices and educational needs of dietary managers in nursing care facilities. 95th Annual Meeting of the International Association for Food Protection, August 3-6, Columbus, OH. Abstract No. P3-56.
  • Shen, C., Geornaras, I., Kendall, P.A., and Sofos, J.N. 2008. Antilisterial activities of salad dressings, without or with prior microwave oven heating, on frankfurters during simulated home storage. 95th Annual Meeting of the International Association for Food Protection, August 3-6, Columbus, OH. Abstract No. P2-50.
  • Yang, H., Kendall, P.A., Medeiros, L., and Sofos, J.N. 2008. Evaluation of household products as sanitizers against Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella Typhimurium. 95th Annual Meeting of the International Association for Food Protection, August 3-6, Columbus, OH. Abstract No. T6-11.
  • Yuan, W., Medeiros, L., Buffer, J., Kendall, P., and Sofos, J. 2008. Registered dietitians and registered nurses lack awareness and knowledge of Listeria monocytogenes, indicating need for continuing education. 95th Annual Meeting of the International Association for Food Protection, August 3-6, Columbus, OH. Abstract No. T6-01.


Progress 09/15/06 to 09/14/07

Outputs
OUTPUTS: The goal of this multidisciplinary, collaborative project involving several institutions and states is to define, develop, and communicate effective Listeria monocytogenes risk reduction strategies for ready-to-eat (RTE) meat and poultry products at the processing, retail/foodservice and consumer levels. Research studies assessed the fate of inoculated L. monocytogenes on commercial ham and uncured turkey breast, formulated with and without potassium lactate/sodium diacetate, under conditions simulating contamination at production and retail followed by home storage. Simulated plant contamination of products without antimicrobials was the worst case scenario relative to pathogen levels to which consumers could be exposed during home storage of product. Lactate/diacetate reduced contamination levels reaching consumers. To help small meat processors meet regulatory requirements for pathogen control, 5 industry and 2 train-the-trainer workshops were conducted. Topics discussed included regulatory requirements, control strategies, sanitary facilities/equipment, sampling plans, data analysis, root cause identification of problems, corrective actions, and validation of interventions. The train-the-trainer workshops (each attended by over 20 extension specialists from more than 15 U.S. states, and Central and South America) were conducted at national meetings. Training materials, including CDs with PowerPoint presentations, were made available to extension agents. Six small/very small processing plants in 3 states participated in a study evaluating Listeria transmission. Completion of 4 samplings in each plant indicated no or very low Listeria prevalence in some plants, while isolation was more common in others, including evidence for persistence of a L. innocua subtype in at least one plant. Stage I of a cross-sectional study, in collaboration with the New York State Department of Agriculture and Markets on transmission/sources of L. monocytogenes in retail environments, tested food (185) and environmental sponge (1158) samples collected from 121 retail establishments over 12 months. Five (2.7 percent) food and 151 (13 percent) environmental samples were positive for L. monocytogenes, with 73 establishments having at least one environmental sample positive. Evidence of a persistent L. monocytogenes subtype was found in 4 out of 5 establishments chosen for follow-up visits. A nationwide web-based survey of 102 dietary managers serving persons at high risk of foodborne illness was conducted to better understand their knowledge and awareness of L. monocytogenes. Most respondents worked for a nursing home or assisted-living facility and indicated low to moderate understanding of L. monocytogenes; over 80 percent served luncheon meats, hot dogs, and prepared salads to high risk patients. Only 5 respondents indicated that they did not serve luncheon meats or hot dogs because of food safety concerns. Over 85 percent reported having protocols for cleaning/sanitizing meat/cheese slicers, kitchen counters, food contact surfaces and refrigerated spaces; fewer (36-52 percent) reported having protocols for cleaning kitchen disposals, drains and sinks. PARTICIPANTS: Principal investigator: John N. Sofos (Colorado State University). Other Colorado State University investigators involved include Patricia A. Kendall, John A. Scanga, Kendra Nightingale, and Ifigenia Geornaras. Partner organizations and collaborators include: Martin Wiedmann (Cornell University), Harshavardhan Thippareddi (University of Nebraska-Lincoln), Lydia Medeiros (Ohio State University), Elizabeth Boyle (Kansas State University), and Dennis Burson (University of Nebraska-Lincoln). TARGET AUDIENCES: Audiences targeted were the meat and poultry processing industry, especially small processors, the retail industry, dietary managers who serve persons at high risk of foodborne illness, other scientists, extension personnel, and regulatory agencies. Data were presented at the 94th Annual Meeting of the International Association for Food Protection (July 8-11, Lake Buena Vista, FL), the 67th Annual Meeting of the Institute of Food Technologists (July 28-August 1, Chicago, IL), and the 40th Annual Meeting of the Society for Nutrition Education (July 28-August 1, Chicago, IL), and eight abstracts were published. Five workshops were conducted and were targeted at small and very small processors. Also, two "train-the-trainer" workshops were conducted at national meetings; Reciprocal Meats Conference (American Meat Science Association Annual Meeting, 2007; Brookings, SD) and at the Annual Meeting of the International Association for Food Protection (Lake Buena Vista, FL). PROJECT MODIFICATIONS: None.

Impacts
Invasive listeriosis is a deadly infection, mostly foodborne, that results in an estimated 2,493 cases and 499 deaths annually in the United States, through meningitis, abortions and stillbirths. The responsible pathogen is Listeria monocytogenes, which survives and multiplies in adverse environments, such as under refrigeration, and may contaminate ready-to-eat (RTE) meat and poultry products. Such products may be contaminated with L. monocytogenes after thermal treatment, which, if properly applied, inactivates cells of bacterial pathogens. Post-processing (post-lethality) contamination or cross-contamination, however, remains a major concern for the meat processing industry, public health agencies and consumers. Such contamination may be introduced accidentally during product slicing and re-packaging, and is of major importance in products that allow growth of the pathogen during distribution, retailing, and storage before consumption. For such products, regulation requires the meat and poultry processing industry to select and apply, as part of their hazard analysis critical control point plan or prerequisite programs, physical interventions and/or chemical antimicrobials. This multidisciplinary, collaborative effort among scientists from several institutions and states includes research, education and outreach components aimed at reducing the risk of listeriosis by intervening at the processing, retail/foodservice, and consumer level. The project evaluates potential human health risks as affected by potential for pathogen growth, and develops antimicrobial alternatives for its control at the production, distribution and consumption level of RTE products, which have been associated with major listeriosis outbreaks in recent years. In addition to laboratory and field research to determine pathogen prevalence and sources of contamination at processing and retail, and efficacy of control factors to minimize presence and survival of the pathogen in RTE meat and poultry products, efforts under this project include workshops and training of personnel, especially of smaller operations, and extension agents to serve in train-the trainer activities, as well as health care providers and at-risk consumers for better control of the pathogen and avoidance of listeriosis. Increased awareness of L. monocytogenes risks and control approaches is needed, especially among high-risk populations and effective educational strategies are necessary at point-of-purchase settings as well as in health clinics and places where seniors and pregnant women congregate. Recommendations to manufacturers should include providing safety labels that combine date labeling and storage instructions without using too many technical words. In general, the results of studies under this project will be valuable to industry, health care providers and advisors of susceptible human populations, and regulators in their efforts to reduce the incidence of listeriosis. The research findings should also be useful in risk assessments, determining proper allocation of resources for listeriosis control, and for establishment of "sell by" and "consume by" date labels for RTE meats.

Publications

  • Byelashov, O.A., Simpson, C.A., Geornaras, I., Kendall, P.A., Scanga, J.A., and Sofos, J.N. 2007. Fate of Listeria monocytogenes on frankfurters at different stages from manufacturing to consumption. 94th Annual Meeting of the International Association for Food Protection, July 8-11, Lake Buena Vista, FL. Abstract No. T6-10.
  • Geornaras, I., Kendall, P.A., Scanga, J.A., and Sofos, J.N. 2007. Survival of Listeria monocytogenes inoculated post-processing on frankfurters formulated with low concentrations of malic acid, sodium citrate, and sodium acetate, and exposed to a heat treatment after packaging. 94th Annual Meeting of the International Association of Food Protection, July 8-11, Lake Buena Vista, FL. Abstract No. P2-20.
  • Simpson, C.A., Byelashov, O., Geornaras, I., Kendall, P.A., Scanga, J.A., Belk, K.E., Smith, G.C., and Sofos, J.N. 2007. Effect of freezing, thawing method, and aerobic storage on the fate of Listeria monocytogenes during home storage of frankfurters. 94th Annual Meeting of the International Association for Food Protection, July 8-11, Lake Buena Vista, FL. Abstract No. P2-56.
  • Sauders, B.D., Farchione, C., Sanchez, M.D., Mangione, K., Corby, J., Stich, S., Rice, D., Fortes, E., and Wiedmann, M. 2007. Prevalence and molecular ecology of Listeria monocytogenes in retail food establishments. 94th Annual Meeting of the International Association for Food Protection, July 8-11, Lake Buena Vista, FL. Abstract No. T4-08.
  • Sofos, J.N. 2007. Overview of emerging foodborne pathogens associated with muscle foods. 67th Annual Meeting of the Institute of Food Technologists, July 28-August 1, Chicago, IL. Abstract No. 195-01.
  • Lianou, A., Geornaras, I., Kendall, P.A., Belk, K.E., Scanga, J.A., Smith, G.C., and Sofos, J.N. 2007. Fate of Listeria monocytogenes in commercial ham, formulated with or without antimicrobials, under conditions simulating contamination in the processing or retail environment and during home storage. J. Food Prot. 70:378-385.
  • Lianou, A., Geornaras, I., Kendall, P.A., Scanga, J.A., and Sofos, J.N. 2007. Behavior of Listeria monocytogenes at 7 degreesC in commercial turkey breast, with or without antimicrobials, after simulated contamination for manufacturing, retail and consumer settings. Food Microbiol. 24:433-443.
  • Lianou, A., and Sofos, J.N. 2007. A review of the incidence and transmission of Listeria monocytogenes in ready-to-eat products in retail and food service environments. J. Food. Prot. 70:2172-2198.
  • Barmpalia-Davis, I.M., Geornaras, I., Kendall, P.A., and Sofos, J.N. 2007. Changes of Listeria monocytogenes counts in a gastrointestinal model following inoculation onto salami or bologna slices and storage at 4 degreesC in vacuum packages. 67th Annual Meeting of the Institute of Food Technologists, July 28-August 1, Chicago, IL. Abstract No. 098-24.
  • Lenhart, J., Kendall, P.A., Doorn, J., Medeiros, L.C., and Sofos, J.N. 2007. Consumer assessment of safety and date labeling statements on ready-to-eat meat and poultry products. 67th Annual Meeting of the Institute of Food Technologists, July 28-August 1, Chicago, IL. Abstract No. 005-02.
  • Lenhart, J., Kendall, P., Schroeder, M., Doorn, J., Medeiros, L., and Sofos, J. 2007. Preventing listeriosis in selected high risk populations: Is the message reaching at-risk audiences? J. Nutrition Educ. Behavior, Abstract P22. 39(Suppl. 4):S113.
  • Sofos, J.N. 2007.What needs to be done to improve food safety. Food Technol. 07.07: 132.
  • Byelashov, O.A., Carlson, B.A., Duran, G., Geornaras, I., Kendall, P.A., Scanga, J.A., Smith, G.C., and Sofos, J.N. 2007. Fate of Listeria monocytogenes during storage of pepperoni. Animal Sciences Research Report, Department of Animal Sciences, Colorado State University, Fort Collins, CO.
  • Byelashov, O.A., Kendall, P.A., Belk, K.E., Scanga, J.A., and Sofos, J.N. 2007. Effect of lactic acid and sodium lauryl sulfate against Listeria monocytogenes on frankfurters. Animal Sciences Research Report, Department of Animal Sciences, Colorado State University, Fort Collins, CO.
  • Yoon, Y., Duran, G., Geornaras, I., Scanga, J.A., Kendall, P.A., Belk, K.E., Smith, G.C., and Sofos, J.N. 2007. Growth rate of Listeria monocytogenes on uncured turkey breast. Animal Sciences Research Report, Department of Animal Sciences, Colorado State University, Fort Collins, CO.
  • Sofos, J.N. 2007. Listeria monocytogenes, is it still an issue in RTE meat and poultry products? Controlling Listeria monocytogenes in ready-to-eat meat and poultry products: a train-the-trainer workshop. Organized in association with the International Association for Food Protection. Lake Buena Vista, FL. 7 July 2007.
  • Sofos, J.N. 2007. Antimicrobial agents to control Listeria monocytogenes on RTE meat and poultry products - an update. Controlling Listeria monocytogenes in ready-to-eat meat and poultry products: a train-the-trainer workshop. Organized in association with the International Association for Food Protection. Lake Buena Vista, FL. 7 July 2007.
  • Wiedmann, M. 2007. Listeria monocytogenes - Ecology of an elusive foodborne pathogen in RTE processing environment. Controlling Listeria monocytogenes in ready-to-eat meat and poultry products: a train-the-trainer workshop. Organized in association with the International Association for Food Protection. Lake Buena Vista, FL. 7 July 2007.


Progress 09/15/05 to 09/15/06

Outputs
This project is a collaborative effort among scientists from several institutions and states, and includes research, education and outreach components to reduce the risk of Listeria monocytogenes transmission through ready-to-eat (RTE) meat and poultry products by intervening at the processing, foodservice, and consumer level. The collaborators had a 2-day planning meeting in Fort Collins and keep in regular contact through conference calls. Relative to laboratory research, a study evaluated 25 L. monocytogenes strains of various serotypes and sources, including clinical and food isolates associated with the same outbreaks, for growth and heat and acid death rates. Extensive variation was observed among the strains. Serotype appeared to play a significant role only with respect to heat resistance. Outbreak-related isolates of serotype 4b demonstrated lower acid death rates compared to other strains. The results of this study should be useful in strain selection for evaluation of antimicrobial alternatives in RTE foods. Additional studies in progress are evaluating antimicrobials for control of Listeria during processing, storage, retail and home handling of products. Collaborators are recruiting plants for studies to understand L. monocytogenes transmission in small and very small processing plant environments. A study is in progress in collaboration with the New York State Department of Agriculture and Markets to develop a better understanding of the transmission and sources of L. monocytogenes at retail. A study was designed to examine consumer awareness of L. monocytogenes, and educational needs regarding food safety and control of listeriosis. Eleven focus groups were conducted in Colorado and Ohio; 6 (n=42) with women of child-bearing age and 5 (n=43) with senior women. Prior to discussions, participants completed a survey regarding food safety knowledge and behaviors associated with Listeria control. The focus groups confirmed the questionnaire results in that consumers tended to be undereducated about L. monocytogenes. The safety labels explaining what "anti-listerial" agents were used in the processing of RTE meat and poultry products were not well received. However, labels giving consumer instructions on how long to keep RTE meats and when to discard after opening were considered. A Listeria Control Input and Planning Workshop was held in Denver, Colorado on September 25-26, 2006, as a pre-conference workshop of the Food Safety Education Conference; over 70 participants contributed input during breakout sessions dealing with each objective of the project at the processing, retail/food service and consumer education stages of the food chain. The project collaborators also presented two breakout sessions on Listeriosis and Listeria Control during the Food Safety Education Conference; they were attended by more than 50 individuals each. On November 14, 2006, the project collaborators presented a 3-hour session on Advanced Listeria Control during a Basic Listeria Control Workshop presented to the meat and poultry industry by the American Meat Institute Foundation in Denver, Colorado; the session was attended by more than 50 individuals.

Impacts
An estimated 2,493 cases of listeriosis and 499 deaths occur annually in the US, as Listeria monocytogenes, the causative agent of this infection, results in meningitis, abortions and stillbirths. The pathogen survives and multiplies in adverse environments, such as under refrigeration, ad may contaminate ready-to-eat (RTE) meat and poultry products. The goals of this multidisciplinary, collaborative effort, among scientists from several institutions and states, include research, education and outreach components aimed at reducing the risk of listeriosis by intervening at the processing, foodservice, and consumer level. The project evaluates potential human health risks as affected by potential for pathogen growth, and develops antimicrobial alternatives for control of the pathogen at the production, distribution and consumption level of RTE products, which have been associated with major listeriosis outbreaks in recent years. Increased awareness of L. monocytogenes risks and control approaches is needed, especially among high-risk populations, and educational strategies are necessary at point-of-purchase settings as well as in health clinics and places where seniors and pregnant women congregate. The results of these studies will be valuable to industry, health care providers and advisors of susceptible human populations, and regulators in their efforts to reduce the incidence of listeriosis. Recommendations to manufacturers should include providing safety labels that combine date labeling and storage instructions without using too many technical words.

Publications

  • Lianou, A., Stopforth,J.D.,Yoon, Y. Wiedmann, M., and Sofos, J.N. 2006. Growth and stress resistance variation among Listeria monocytogenes strains of various serotypes and origin in culture broth. J. Food Prot. (69)2640-2647.
  • Sofos, J.N. and Yoon, Y. 2006. Safer food using predictive modeling; Novel approaches to control Listeria monocytogenes in ready-to-eat meat products. Fleischwirtschaft Int. 2006(3)16-18, 21.
  • Lianou, A., Geornaras, I., Kendall,P.A., Belk, K.E., Scanga, J.A., Smith, G.C., and Sofos, J.N. 2006. Effect of antimicrobials, point of inoculation and home storage conditions on Listeria monocytogenes growth on commercial uncured turkey breast. 93rd Annual Meeting of the International Association of Food Protection, August 13-16, Calgary, Alberta, Canada. Abstract No. P5-28.
  • Duran, G. and Sofos, J.N. 2006. Effects of low equal molar concentrations of three food grade acids on Listeria monocytogenes in bologna. 93rd Annual Meeting of the International Association of Food Protection, August 13-16, Calgary, Alberta, Canada. Abstract No. T6-02.
  • Sofos, J.N., Lianou,A., and Geornaras, I. 2006. Behavior of Listeria monocytogenes in Delicatessen meat and poultry products under two contamination scenarios. FoodMicro 2006, the 20th Intern. ICFMH Symposium, Alma Matter Studiorum Universita di Bologna, August 29 to September 2, Bologna, Italy. p. 193.