Source: EASTERN REGIONAL RES CENTER submitted to
MICROBIAL MODELING AND BIOINFORMATICS FOR FOOD SAFETY AND SECURITY
Sponsoring Institution
Agricultural Research Service/USDA
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0410312
Grant No.
(N/A)
Project No.
1935-42000-057-00D
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Feb 8, 2006
Project End Date
Feb 6, 2011
Grant Year
(N/A)
Project Director
JUNEJA V K
Recipient Organization
EASTERN REGIONAL RES CENTER
(N/A)
WYNDMOOR,PA 19118
Performing Department
(N/A)
Non Technical Summary
(N/A)
Animal Health Component
100%
Research Effort Categories
Basic
0%
Applied
100%
Developmental
0%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
7123320110050%
7123430110030%
7123520110010%
7123260110010%
Goals / Objectives
To evaluate, validate, and where necessary, develop new innovative, robust and valid predictive models for the responses of microbial pathogens, including foodborne threat agents, in select food matrices, as a function of: temperature, food formulation, competitive microflora, physiological history, and surface transfer. To develop novel approaches to assess model performance and robustness, leading to more efficient strategies for producing and extrapolating models to different classes of food. To determine the probability distribution of lag phase duration (LPD) for foodborne pathogens, as a function of the previous bacterial physiological history, to allow risk managers to estimate worst-and best-case scenarios for pathogen behavior, depending on likely sources of contamination; To identify molecular markers that discriminate bacterial lag, growth and stationary phases, thus leading to more mechanistic models and greater certainty for LPD prediction.
Project Methods
Quantitative data will be collected for the effects of selected environmental parameters on foodborne pathogen growth, survival and inactivation. Relevant environmental conditions will include food formulation, native microbial flora, inoculum level, bacterial history, and the effects of food process operations. Priority pathogen-food combinations will be identified through stakeholder interactions and by identifying sensitive data gaps in microbial risk assessment. Experimental data will be used to confirm and where necessary produce primary growth and inactivation models, as well as probabilistic models for growth/no growth interfaces and microbial transfer among food processing surfaces. Model performance will be described using independent validation data from ongoing experiments with food matrices and microbiology databases such as ComBase. The resulting technologies will be transferred to stakeholders vis the ARS Pathogen Modeling Program and process risk model software.

Progress 02/08/06 to 02/06/11

Outputs
Progress Report Objectives (from AD-416) To evaluate, validate, and where necessary, develop new innovative, robust and valid predictive models for the responses of microbial pathogens, including foodborne threat agents, in select food matrices, as a function of: temperature, food formulation, competitive microflora, physiological history, and surface transfer. To develop novel approaches to assess model performance and robustness, leading to more efficient strategies for producing and extrapolating models to different classes of food. To determine the probability distribution of lag phase duration (LPD) for foodborne pathogens, as a function of the previous bacterial physiological history, to allow risk managers to estimate worst-and best- case scenarios for pathogen behavior, depending on likely sources of contamination; To identify molecular markers that discriminate bacterial lag, growth and stationary phases, thus leading to more mechanistic models and greater certainty for LPD prediction. Approach (from AD-416) Quantitative data will be collected for the effects of selected environmental parameters on foodborne pathogen growth, survival and inactivation. Relevant environmental conditions will include food formulation, native microbial flora, inoculum level, bacterial history, and the effects of food process operations. Priority pathogen-food combinations will be identified through stakeholder interactions and by identifying sensitive data gaps in microbial risk assessment. Experimental data will be used to confirm and where necessary produce primary growth and inactivation models, as well as probabilistic models for growth/no growth interfaces and microbial transfer among food processing surfaces. Model performance will be described using independent validation data from ongoing experiments with food matrices and microbiology databases such as ComBase. The resulting technologies will be transferred to stakeholders vis the ARS Pathogen Modeling Program and process risk model software. Experiments examining the growth of L. monocytogenes, E. coli O157:H7, and Salmonella spp. as affected by sodium lactate and storage temperature in ready-to-eat ham and growth probability of E. coli O157:H7 as affected by salt, sodium pyrophosphate and sodium lactate in ground beef were completed. Experiments on surface decontamination and growth of L. monocytogenes, E. coli O157:H7, and Salmonella spp. with lactic acid, sodium lactate and diacetate on ready-to-eat meat is in progress. A series of experiments were conducted to determine the germination and outgrowth of Clostridium perfringens spores during cooling of cooked pork products. Finally, predictive model for growth of Clostridium perfringens during cooling of cooked products based on the product composition factors is being developed. The growth data/predictive model on the safe cooling rate of meat will enable the food industry to assure that cooked products remain pathogen-free. Research was conducted to develop predictive models for non-O157 Shiga toxin-producing E. coli (STEC) in ground beef and spinach. A cocktail of different strains was inoculated in ground beef and spinach and incubated at different temperatures to develop growth curves. The growth curves were analyzed for developing mathematical models. Research was also conducted to investigate the effect of temperature on the growth of microorganisms. As a result of this research, a new empirical mathematical model that can more realistically describe the relationship between temperature and bacterial growth rate was established and validated. Further, this research led to the development of a thermodynamic model that is based on the Arrhenius equation. This is a new mathematical model that can accurately evaluate the effect of temperature on bacterial growth. The research is related to 2006-2010 NP 108 Action Plan Sections 1.2.7 (Risk Assessment) and 1.2.9 (Food Security). The research work addresses the objectives of producing improved Quantitative Microbial Risk Assessment through more accurate exposure assessment and risk characterization, robust and validated process risk models that address hazards in complex food matrices, and validated models that predict the effect of specific intervention strategies on threat agents. Accomplishments 01 Adequate cooking, cooling, and proper product formulation ensure safety against pathogens in cooked food products while minimizing quality losse ARS researchers at Wyndmoor, PA, conducted research to develop mathematical models for describing the effect of cooking temperatures (5 to 71�C) and antimicrobial agents (such as cinnamaldehyde and carvacrol) on inactivation of Salmonella in ground chicken, the impact of product formulation (salt, sodium pyrophosphate and sodium lactate) on survival E. coli O157:H7 in beef, and the difference in cooling rates on the germination and outgrowth of Clostridium perfringens spores in cooked beef. These models will assist food processors in designing cooking and cooling processes for the production of safe chicken and beef products with extended shelf life, and help the manufacturers to select product formulations that enhance the safety and quality of raw and cooked meat products during distribution and storage.

Impacts
(N/A)

Publications

  • Juneja, V.K., Marks, H.M., Huang, L., Thippareddi, H. 2011. Predictive model for growth of Clostridium perfringens during cooling of cooked uncured meat and poultry. Food Microbiology. 28:791-795.
  • Grosulescu, C., Ravishankar, S., Juneja, V.K. 2011. Effects and interactions of sodium lactate, sodium diacetate, and pediocin on the thermal inactivation of starved cells of Listeria monocytogenes on the surface of bologna. Food Microbiology. 28:440-446.
  • Hwang, C., Sheen, S. 2011. Growth characteristics of Listeria monocytogenes as affected by a -native microflora in cooked ham under refrigerated and temperature abuse conditions. Food Microbiology. 28:350- 355.
  • Oscar, T.P. 2011. Development and validation of a predictive model for survival and growth of Salmonella on chicken skin stored at 4 to 12 deg C. Journal of Food Protection. 74(2):279-284.
  • Bhaduri, S., Chaney, K.J., Smith, J.L. 2011. A procedure for monitoring the presence of the virulence plasmid (pYV) in Yersinia pestis under culture conditions. Foodborne Pathogens and Disease. 8:459-463.
  • Bhaduri, S. 2011. Effect of salt and acidic pH on the stability of virulence plasmid (pYV) in Yersinia enterocolitica and expression of virulence-associated characteristics. Food Microbiology. 28:171-173.
  • Hwang, C., Juneja, V.K. 2011. The effects of salt, sodium pyrophosphate and sodium lactate on the probability of growth of Escherichia coli O157:H7 in ground beef. Journal of Food Protection. 74(4):622-626.


Progress 10/01/09 to 09/30/10

Outputs
Progress Report Objectives (from AD-416) To evaluate, validate, and where necessary, develop new innovative, robust and valid predictive models for the responses of microbial pathogens, including foodborne threat agents, in select food matrices, as a function of: temperature, food formulation, competitive microflora, physiological history, and surface transfer. To develop novel approaches to assess model performance and robustness, leading to more efficient strategies for producing and extrapolating models to different classes of food. To determine the probability distribution of lag phase duration (LPD) for foodborne pathogens, as a function of the previous bacterial physiological history, to allow risk managers to estimate worst-and best- case scenarios for pathogen behavior, depending on likely sources of contamination; To identify molecular markers that discriminate bacterial lag, growth and stationary phases, thus leading to more mechanistic models and greater certainty for LPD prediction. Approach (from AD-416) Quantitative data will be collected for the effects of selected environmental parameters on foodborne pathogen growth, survival and inactivation. Relevant environmental conditions will include food formulation, native microbial flora, inoculum level, bacterial history, and the effects of food process operations. Priority pathogen-food combinations will be identified through stakeholder interactions and by identifying sensitive data gaps in microbial risk assessment. Experimental data will be used to confirm and where necessary produce primary growth and inactivation models, as well as probabilistic models for growth/no growth interfaces and microbial transfer among food processing surfaces. Model performance will be described using independent validation data from ongoing experiments with food matrices and microbiology databases such as ComBase. The resulting technologies will be transferred to stakeholders vis the ARS Pathogen Modeling Program and process risk model software. Mathematical equations for description the growth, survival or inactivation of L. monocytogenes in smoking process,in cooked ham, and in ham, egg, pasta, and potato salads were developed into Excel models. All data were formatted in Excel spreadsheet for Combase submission. A series of experiments were conducted to determine the germination and outgrowth of Clostridium perfringens spores during cooling of cooked pork products. Predictive model for growth of Clostridium perfringens during cooling of cooked pork products based on the product composition factors is being developed. The growth data /predictive models on the safe cooling rate of meat will enable the food industry to assure that cooked products remain pathogen-free. Data were collected in a series of experiments with chicken meats (white and dark meat) and other initial doses of Salmonella and with Salmonella on chicken skin that was frozen for one week. These data indicated that the model did not provide acceptable predictions of Salmonella growth and survival on chicken skin when other initial doses of the pathogen were present but that the model did provide acceptable predictions of Salmonella growth and survival on chicken skin when the pathogen was subjected to a previous history of freezing for one week before the experiment. These results indicate that the model should be expanded to include other initial doses of Salmonella. This expanded model will provide the chicken industry and regulators with an improved predictive tool for assessing and managing this risk to public health. Experiments were conducted to determine the impact of prior history on the lag phase duration of L. monocytogenes and Escherichia coli O157:H7. The pathogens were exposed to 25 - 75ppm chlorine for 1 h prior to assessing the lag phase of 3 � 4 log CFU/g cells on sliced ham at temperatures ranging from 4 � 24C. While lag phase of L. monocytogenes varied considerably, E. coli O157:H7 lag phase was longer after exposure to higher chlorine concentration and at lower incubation temperatures. Models to predict the lag time and growth rate were developed and validated. A series of experiments were conducted to study the growth of Y. pestis ranging from 0-30C in pork and also to investigate the stability of virulent plasmid during its growth in ground pork. Yersinia pestis grew at storage temperatures from 10-30C and reached maximum population density. The virulence plasmid was retained in Y. pestis in ground pork. stored at refrigerator temperatures or during its growth at 10-30C. The fate of RpoS, an alternate sigma factor responsible for regulating many of the genes responsible for survival of bacteria, in the transition from stationary phase to lag phase growth using Escherichia coli O157:H7 as a model strain was studied. To verify that E. coli O157:H7 (EDL933 and Sakai strains) expressed a full length version of RpoS, the DNA sequence of this gene in EDL933 and Sakai strains has been initiated and the sequence data are being generated. Significant Activities that Support Special Target Populations ARS operates a USDA/1890 Center of Excellence Program at University of Maryland Eastern Shore in Princess Anne, MD that specifically targets a minority, historically underserved group (African Americans) for careers in agriculture. Activities this year included: 1) service on six graduate student committees; 2) two guest lectures in a graduate level food science class; 3) and provision of research experiences and training in predictive microbiology for three undergraduate and four graduate students. Accomplishments 01 Proper means for cooling of cooked beef. Inadequate rate and extent of cooling of cooked foods is a major food safety problem. ARS scientists (Wyndmoor, PA), determined the germination and outgrowth of Clostridium perfringens spores during cooling of cooked beef products. Predictive model for growth of Clostridium perfringens during cooling of cooked bee products based on the product composition factors was developed. The growth data /predictive models on the safe cooling rate of meat will provide the food industry means to assure that cooked products remain pathogen-free. 02 Predictive model for L. monocytogenes in ready-to-eat (RTE) meat. L. monocytogenes is pathogen commonly associated with foodborne illness caused by consumption of contaminated ready-to-eat meat. ARS scientists in (Wyndmoor, PA) developed models to describe the survival and growth o L. monocytogenes and native microflora in ready-to-eat ham. Excel models for L. monocytogenes in smoking process, in cooked ham, in ham, egg, pas and potato salads were posted on ERRC-ARS website. The models will hel the manufacturers to determine the effect of temperature changes during distribution and storage of ham on the safety and quality of their products. 03 Transfer of pathogens during mechanical slicing of deli meats. Food safety managers currently lack the ability to predict the microbial pathogen transfer in slicing operation for ready-to-eat (RTE) foods. Models were developed by ARS scientists in (Wyndmoor, PA) for pathogen transfer prediction during mechanical slicing for RTE deli meats. The shear stress may reduce a large amount (99%) of pathogens, such as Listeria monocytogenes, as demonstrated using confocal microscopy. Predictive models will be useful for food manufacturers in developing Hazard Analysis Critical Control Points (HACCP) plans and in risk assessments for RTE meats. 04 Chemical hurdle for improved food safety. Listeria monocytogenes is an opportunistic human bacterial pathogen of food origin that causes illnes in certain at risk groups, such as pregnant women, newborn babies and adults with underlying health problems. Due to the high case-fatality ra (20%), development of control measures for this pathogen is of major interest to the food industry. In collaboration with university scientis ARS scientists in Princess Anne, MD demonstrated that a commercial formulation (Purasol P Opti.Form 4TM) of organic acid salts (sodium and potassium lactate and sodium diacetate), which are recognized as safe fo additives, exhibited pronounced inhibition of the pathogen in broth formulations that simulated meat and poultry products stored at cold temperatures. The resulting predictive model can be used to design a substantial chemical hurdle to the survival and outgrowth of Listeria monocytogenes in meat and poultry products stored at a range of temperatures. 05 Use of marinade to guard against Salmonella problems. Salmonella contamination of chicken is a major public health problem throughout the world. Soaking chicken in a marinade before cooking to impart a unique flavor is a common practice. Some marinades contain ingredients, such a vinegar and spices, which can reduce or eliminate human pathogens like Salmonella. In collaboration with a university scientist, ARS scientist in Princess Anne, MD found that overnight cold storage of chicken in an Italian-style marinade, which contained vinegar and spices, greatly reduced Salmonella levels making it a simple and low cost method that consumers can use to improve not only the flavor but also the safety of chicken for their families. 06 Not all Salmonella are created equal. Chickens from a commercial processing plant were found to be contaminated most often with one of tw types of Salmonella: Typhimurium or Kentucky. Salmonella Kentucky is rarely found in human clinical cases of foodborne illness, whereas Salmonella Typhimurium is often found in such cases. ARS scientists in Princess Anne, MD discovered that Salmonella Kentucky grows much slower chicken than Salmonella Typhimurium, which may explain why it rarely causes illness in humans. They also developed a computer model that predicts the difference in risk to humans of chicken contaminated with these two types of Salmonella. The model is projected to save the chick industry and consumers millions of dollars per year by better predicting chicken safety. 07 Virulent plasmid stability of Yersinia pestis in ground beef. To fully assess the potential risk of illness, ARS scientist (Wyndmoor, PA) determined the stability of the virulent plasmid in Y. pestis during its growth in raw ground beef. The virulence-associated plasmid was retained in Y. pestis during its growth in ground pork and therefore, pork contaminated with Y. pestis could cause disease due to refrigeration failure, temperature abuse (10-25C), and improper cooling. The resultan disease may lead to outbreaks of highly infectious pneumonic plague. Understanding on the growth behavior of the pathogen will reduce the uncertainty in risk assessments designed to manage threats to the US foo supply and provide risk managers with greater certainty in estimating th impact of Y. pestis in the safety of food.

Impacts
(N/A)

Publications

  • Juneja, V.K., Porto Fett, A.C., Call, J.E., Marks, H., Tamplin, M., Luchansky, J.B. 2010. Thermal inactivation of Bacillus anthracis Sterne in irradiated ground beef heated in a water bath or cooked on commercial grills. Innovative Food Science and Emerging Technologies. 11:123-129.
  • Sheen, S., Hwang, C. 2010. Mathematical modeling the cross-contamination of Escherichia coli O157:H7 on the surface of ready-to-eat meat product while slicing. Food Microbiology. 27:37-43.
  • Juneja, V.K., Marks, H.L., Thippareddi, H. 2010. Predictive model for growth of Clostridium perfringens during cooling of cooked ground pork. Innovative Food Science & Emerging Technologies. 11:146-154.
  • Oscar, T.P. 2009. General regression neural network and Monte Carlo simulation model for survival and growth of Salmonella on raw chicken skin as a function of serotype, temperature and time for use in risk assessment. Journal of Food Protection. 72(10):2078-2087.
  • Maks, N., Zhu, L., Juneja, V.K., Ravishankar, S. 2010. Sodium lactate, sodium diacetate and pediocin: effects and interactions on the thermal inactivation of Listeria monocytogenes on bologna. Food Microbiology. 27:64-69.
  • Bhaduri, S. 2010. Effect of fat in ground beef on the growth and virulence plasmid (pYV) stability in Yersinia pestis. International Journal of Food Microbiology. 136:372-375.
  • Hwang, C. 2010. Delicatessen salads in "refrigerated ready-to-eat foods: microbial concerns and control measures". In: Hwang, C.A., Huang, L., editors.Ready-to-Eat-Foods: Microbial Concerns and Control Measures. New York, NY: CRC Press. p. 61-80.
  • Hwang, C., Sheen, S., Juneja, V.K. 2009. Effect of salt, smoke compound and temperature on the survival of Listeria monocytogenes in salmon during simulated smoking processes. Journal of Food Science. 74(9):M522:M529.
  • Juneja, V.K., Hwang, C., Friedman, M. 2010. Thermal inactivation and post- treatment growth during storage of multiple Salmonella serotypes in ground beef as affected by sodium lactate and oregano oil. Journal of Food Science. 75(1):M1-M6.
  • Juneja, V.K., Porto Fett, A.C., Gartner, K., Tuft, L., Luchansky, J.B. 2010. Potential for growth of Clostridium perfringens from spores in pork scrapple during cooling. Foodborne Pathogens and Disease. 7(2)153-157.
  • Abou-Zeid, K.A., Yoon,, K.S., Oscar, T.P., Whiting, R.C. 2009. Development and Validation of a Predictive model for Listeria monocytogenes Scott A as a function of Temperature, pH and Lactate and Diacetate Mixture. Journal of Microbiology and Biotechnology. 19(7):718-726.
  • Oscar, T.P., Singh, M. 2009. Persistance of Salmonells spp. on Chicken Skin after Exposure to an Italian Marinade. Journal of Rapid Methods and Automation in Microbiology. 17(3):369-382.


Progress 10/01/08 to 09/30/09

Outputs
Progress Report Objectives (from AD-416) To evaluate, validate, and where necessary, develop new innovative, robust and valid predictive models for the responses of microbial pathogens, including foodborne threat agents, in select food matrices, as a function of: temperature, food formulation, competitive microflora, physiological history, and surface transfer. To develop novel approaches to assess model performance and robustness, leading to more efficient strategies for producing and extrapolating models to different classes of food. To determine the probability distribution of lag phase duration (LPD) for foodborne pathogens, as a function of the previous bacterial physiological history, to allow risk managers to estimate worst-and best- case scenarios for pathogen behavior, depending on likely sources of contamination; To identify molecular markers that discriminate bacterial lag, growth and stationary phases, thus leading to more mechanistic models and greater certainty for LPD prediction. Approach (from AD-416) Quantitative data will be collected for the effects of selected environmental parameters on foodborne pathogen growth, survival and inactivation. Relevant environmental conditions will include food formulation, native microbial flora, inoculum level, bacterial history, and the effects of food process operations. Priority pathogen-food combinations will be identified through stakeholder interactions and by identifying sensitive data gaps in microbial risk assessment. Experimental data will be used to confirm and where necessary produce primary growth and inactivation models, as well as probabilistic models for growth/no growth interfaces and microbial transfer among food processing surfaces. Model performance will be described using independent validation data from ongoing experiments with food matrices and microbiology databases such as ComBase. The resulting technologies will be transferred to stakeholders vis the ARS Pathogen Modeling Program and process risk model software. Significant Activities that Support Special Target Populations A series of experiments were being conducted to determine the influence of nitrite (0 to 200 ppm), NaCl (0 to 6%), and sodium pyrophosphate (0 to 0.5%) levels on the germination and outgrowth of Clostridium perfringens spores during cooling of cooked beef and poultry products. Finally, predictive model for growth of Clostridium perfringens during cooling of cooked beef and poultry products based on these product composition factors are being developed. The growth data /predictive models on the safe cooling rate of meat will enable the food industry to assure that cooked products remain pathogen-free. A series of experiments were conducted to investigate and model the growth and survival of Salmonella on chicken skin as a function of strain variation, initial dose and previous history. Salmonella serotype Kentucky was found to grow slower than serotypes Typhimurium and Hadar, which had similar growth. Survival and growth of Salmonella was found to differ as a function of initial dose. Freezing of chicken skin for one week did not alter the subsequent growth and survival of Salmonella. A general regression neural network model for survival and growth of Salmonella on chicken skin as a function of time, temperature and serotype was developed. Experiments were conducted to determine the impact of prior history on the lag phase duration of L. monocytogenes and Escherichia coli O157:H7. The pathogens were exposed to 25 - 75ppm chlorine for 1 h prior to assessing the lag phase of 3 � 4 log CFU/g cells on sliced ham at temperatures ranging from 4 � 24C. While lag phase of L. monocytogenes varied considerably, E. coli O157:H7 lag phase was longer after exposure to higher chlorine concentration and at lower incubation temperatures. The fate of RpoS, an alternate sigma factor responsible for regulating many of the genes responsible for survival of bacteria, in the transition from stationary phase to lag phase growth using Escherichia coli O157:H7 as a model strain was studied. To verify that E. coli O157:H7 (EDL933 and Sakai strains) expressed a full length version of RpoS, the DNA sequence of this gene in EDL933 and Sakai strains has been initiated and the sequence data are being generated. Technology Transfer Number of Web Sites managed: 3

Impacts
(N/A)

Publications

  • Bhaduri, S., Wesley, I.V., Richards, H., Draughon, A., Wallace, M. 2009. Clonality and Antibiotic Susceptibility of Yersinia enterocolitica Isolated From U.S. Market Weight Hogs. Foodborne Pathogens and Disease. 6(3):351-356.
  • Bhaduri, S., O Connor, C. 2008. Comparison of Virulence Plasmid (pYV/pCD)- Associated Phenotypes in Yersinia Species. Journal of Food Safety. 28:453- 466.
  • Hwang, C., Porto Fett, A.C., Juneja, V.K., Ingham, S., Ingham, B., Luchansky, J.B. 2009. Modeling the survival of escherichia coli o157:h7, listeria monocytogenes and salmonella typhimurium during fermentation, drying, and storage of soudjouk-style feremented sausage. International Journal of Food Microbiology. 129:244-252.
  • Juneja, V.K., Marks, H., Thippareddi, H. 2009. PREDICTIVE MODEL FOR GROWTH OF CLOSTRIDIUM PERFRINGENS DURING COOLING OF COOKED GROUND CHICKEN. Innovative Food Science and Emerging Technologies. 10:260-266.
  • Juneja, V.K., Melendes, M., Huang, L., Subbiah, J., Thippareddi, H. 2009. Mathematical modeling of growth of Salmonella in raw ground beef under isothermal conditions from 10 to 45 Degree C. International Journal of Food Microbiology. 131:106-111.
  • Juneja, V.K., Bari, M.L., Inatsu, S., Kawamoto, S., Friedman, M. 2009. Thermal Destruction of Escherichia coli O157:H7 in Sous-vide Cooked Ground Beef as affected by Tea Leaf and Apple Skin Powders. Journal of Food Protection. 72(4):860-865.
  • Wesley, I.V., Bhaduri, S., Bush, E. 2008. Prevalence of Yersinia enterocolitica in market weight hogs in the United States. Journal of Food Protection. 71(6):1162-1168.
  • Juneja, V.K., Friedman, M. 2008. Carvacrol and Cinnamaldehyde Facilitate Thermal Destruction of Escherichia coli O157:H7 in Raw Ground Beef. Journal of Food Protection. 71(8):1604-1611.
  • Oscar, T.P. 2009. PREDICTIVE MODEL FOR SURVIVAL AND GROWTH OF SALMONELLA TYPHIMURIUM DT104 ON CHICKEN SKIN DURING TEMPERATURE ABUSE. Journal of Food Protection. 72(2):304-314.
  • Hwang, C. 2009. THE PROBABILITY OF GROWTH OF LISTERIA MONOCYTOGENES IN SIMULATED SMOKED SALMON AND TYPTIC SOY BROTH AS AFFECTED BY SALT, SMOKE COMPOUND AND STORAGE TEMPERATURES. International Journal of Food Microbiology. 129:244-252.
  • Okahisa, N., Inatsu, Y., Juneja, V.K., Kawamoto, S. 2008. Evaluation and control of the risk of food borne pathogens and spoilage bacteria present in �Awa-Uirou�, a sticky rice cake containing sweet red bean paste. Foodborne Pathogens and Disease. 5(3):351-359.


Progress 10/01/07 to 09/30/08

Outputs
Progress Report Objectives (from AD-416) To evaluate, validate, and where necessary, develop new innovative, robust and valid predictive models for the responses of microbial pathogens, including foodborne threat agents, in select food matrices, as a function of: temperature, food formulation, competitive microflora, physiological history, and surface transfer. To develop novel approaches to assess model performance and robustness, leading to more efficient strategies for producing and extrapolating models to different classes of food. To determine the probability distribution of lag phase duration (LPD) for foodborne pathogens, as a function of the previous bacterial physiological history, to allow risk managers to estimate worst-and best- case scenarios for pathogen behavior, depending on likely sources of contamination; To identify molecular markers that discriminate bacterial lag, growth and stationary phases, thus leading to more mechanistic models and greater certainty for LPD prediction. Approach (from AD-416) Quantitative data will be collected for the effects of selected environmental parameters on foodborne pathogen growth, survival and inactivation. Relevant environmental conditions will include food formulation, native microbial flora, inoculum level, bacterial history, and the effects of food process operations. Priority pathogen-food combinations will be identified through stakeholder interactions and by identifying sensitive data gaps in microbial risk assessment. Experimental data will be used to confirm and where necessary produce primary growth and inactivation models, as well as probabilistic models for growth/no growth interfaces and microbial transfer among food processing surfaces. Model performance will be described using independent validation data from ongoing experiments with food matrices and microbiology databases such as ComBase. The resulting technologies will be transferred to stakeholders vis the ARS Pathogen Modeling Program and process risk model software. Significant Activities that Support Special Target Populations The research is relevant to Component 1.2 (Pathogen Reduction Postharvest) in the 2006-2010 NP 108 Action Plan. We defined the heat treatment (55-73.9C) required to achieve a specified lethality for E. coli O157:H7 in ground beef. The thermal death predictive model for the pathogen, which can predict D-values for any combinations of the factors that are within the range of those tested, was developed. Using these inactivation kinetics or predictive model for E. coli O157:H7, food processors can design thermal processes for the production of a safe beef product with extended shelf life. The research is relevant to Component 1.2 (Pathogen Reduction Postharvest) in the 2006-2010 NP 108 Action Plan. In collaboration with University of Maryland, Eastern Shore (UMES) faculty and students completed a survey of Salmonella strains in a commercial processing plant including characterization of the strains for antimicrobial resistance patterns. Selected strains from this study will be used in future modeling studies to investigate, characterize and model strain variation effects on Salmonella growth and survival on poultry during processing, distribution, handling and storage. The research is relevant to Component 1.2 (Pathogen Reduction Postharvest) in the 2006-2010 NP 108 Action Plan. In collaboration with UMES faculty and students, characterized the growth and survival kinetics of Listeria monocytogenes in broth culture as a function of temperature, pH and sodium lactate/diacetate levels. The data will be used to develop and validate a predictive model for growth and survival of Listeria monoctyogenes in ready-to-eat foods. The research is relevant to Component 1.2 (Pathogen Reduction Postharvest) in the 2006-2010 NP 108 Action Plan. Developed and validated a model for growth of Salmonella Typhimurium DT104 from a low initial dose on chicken frankfurters with native microflora. This is the first model for growth of any strain of Salmonella on a ready-to-eat meat product with native microflora. Growth of Salmonella on chicken frankfurters was restricted by the native micro-flora and food formulation, which contained multiple anti-microbial compounds. Thus, the model will benefit the poultry industry by providing predictions that do not over-estimate the risk of Salmonella growth and infection compared to exiting models developed in sterile food systems. Significant Activities that Support Special Target Populations Collaborated with a small producer of fermented sausage named Mediterranean Foods, a company with 2 employees and an annual sale of less than $200,000, located in Upper Darby, Pennsylvania, to examine the behavior of E. coli O157:H7, Salmonella, and L. monocytogenes on fermented, semi-dry sausage introduced by post-processing contamination. The producer provides finished commercial products, and ARS conducts the challenge study. Three minority students were hired and assisted in this research as part of the ARS/1890 Center of Excellence at the University of Maryland Eastern Shore. The Center of Excellence was established to promote interest among minorities for pursuing advanced careers in agriculture research and to strengthen the relationship between USDA and 1890 Institutions. Technology Transfer Number of New/Active MTAs(providing only): 2 Number of Web Sites managed: 3

Impacts
(N/A)

Publications

  • Juneja, V.K. 2007. Thermal inactivation of salmonella spp. in chicken as affected by ph of the meat. International Journal of Food Science and Technology. 42:1443-1448.
  • Hwang, C., Tamplin, M. 2007. Modeling the Lag Phase and Growth Rate of Listeria monocytogenes in Ground Ham Containing Sodium Lactate and Sodium Diacetate at Various Storage Temperatures. Journal of Food Science and Technology. 72(7):M246-M253.
  • Juneja, V.K., Sheen, S., Tewari, G. 2007. Intervention technologies for food safety and preservation. In: Wilson, C.L. editor. Microbial Food Contamination. 2nd edition. CRC Press. Ames, Iowa. p. 347-393.
  • Juneja, V.K., Marks, H., Thippareddi, H.H. 2007. Predictive model for growth of clostridium perfringens during cooling of cooked uncured beef. Food Microbiology. 25:42-55.
  • Hoque, M.M., Inatsu, M.B., Juneja, V.K., Kawamoto, S. 2007. Antibacterial activity of guava (psidium guajava l.) and neem (azadirachta indica a. juss.)extracts against food borne pathogens and spoilage bacteria. Foodborne Pathogens & Disease. 4:481-488.
  • Velugoti, P.R., Rajagopal, L., Juneja, V.K., Thippareddi, H. 2007. Use of Calcium, Potassium, and Sodium Lactates to Control Germination and Outgrowth of Clostridium perfringens Spores during Chilling of Injected Pork. Food Microbiology. 24(7-8):687-694.
  • Aarnisalo, K., Sheen, S., Raaska, L., Tamplin, M. 2007. Modelling transfer of listeria monocytogenes during slicing of "gravad" salmon. International Journal of Food Microbiology. 118(1):69-78.
  • Sheen, S., Hwang, C. 2008. Modeling Transfer of Listeria monocytogenes on Deli Meat During Mechanical Slicing. Foodborne Pathogens and Disease. 5(2) :135-146.
  • Hwang, C. 2007. The Effect of Salt, Smoke Compound, and Storage Temperature on the Growth of Listeria monocytogenes in Simulated Smoked Salmon. Journal of Food Protection. 70:2321-2328.
  • Parveen, S., Taabodi, M., Mohamed, T., Schwarz, J.P., Oscar, T.P., Harter- Dennis, J., Hubert, S., White, D. 2007. Prevalence and Antimicrobial Resistance of Salmonella spp. Recovered from Processed Poultry. Journal of Food Protection. 70(11):2466-2472.
  • Abou-Zeid, K.A., Yoon, K.S., Oscar, T.P., Schwarz, J.G., Hashem, F.M., Whiting, R.C. 2007. Survival and growth of Listeria monocytogenes in broth as a function of temperature, pH, and potassium lactate and sodium diacetate concentrations. Journal of Food Protection. 70(11):2620-2625.
  • Oscar, T.P. 2008. Predictive model for verification of critical control points for growth of salmonella typhimurium dt104 on chicken frankfurters after thermal processing. International Journal of Food Microbiology. 71(6) :1135-1144.
  • Hoque, M.M., Inatsu, M.B., Juneja, V.K., Kawamoto, S. 2007. Antimicrobial Activity of Cloves and Cinnamon Extracts against Food Borne Pathogens and Spoilage bacteria, and Inactivation of Listeria monocytogenes in Ground Chicken meat with their Essential oils. Journal of Food Science and Technology. 72:9-21.
  • Sheen, S., Bao, G., Cooke, P.H. 2008. Food surface texture measurement using reflective confocal laser scanning microscopy. Journal of Food Science and Technology. 73(5):227-234.


Progress 10/01/06 to 09/30/07

Outputs
Progress Report Objectives (from AD-416) To evaluate, validate, and where necessary, develop new innovative, robust and valid predictive models for the responses of microbial pathogens, including foodborne threat agents, in select food matrices, as a function of: temperature, food formulation, competitive microflora, physiological history, and surface transfer. To develop novel approaches to assess model performance and robustness, leading to more efficient strategies for producing and extrapolating models to different classes of food. To determine the probability distribution of lag phase duration (LPD) for foodborne pathogens, as a function of the previous bacterial physiological history, to allow risk managers to estimate worst-and best- case scenarios for pathogen behavior, depending on likely sources of contamination; To identify molecular markers that discriminate bacterial lag, growth and stationary phases, thus leading to more mechanistic models and greater certainty for LPD prediction. Approach (from AD-416) Quantitative data will be collected for the effects of selected environmental parameters on foodborne pathogen growth, survival and inactivation. Relevant environmental conditions will include food formulation, native microbial flora, inoculum level, bacterial history, and the effects of food process operations. Priority pathogen-food combinations will be identified through stakeholder interactions and by identifying sensitive data gaps in microbial risk assessment. Experimental data will be used to confirm and where necessary produce primary growth and inactivation models, as well as probabilistic models for growth/no growth interfaces and microbial transfer among food processing surfaces. Model performance will be described using independent validation data from ongoing experiments with food matrices and microbiology databases such as ComBase. The resulting technologies will be transferred to stakeholders vis the ARS Pathogen Modeling Program and process risk model software. Significant Activities that Support Special Target Populations Research is also conducted under the following Agreements: 1935-42000-057- 01G "Eliminating Listeria Monocytogenes from Ready-to-Eat Products" A General Assistance Grant with University of Arkansas. 1935-42000-057-02G "Dose Response of Listeria Monocytogenes in Pregnant Guinea Pigs for Use In Risk Assessment" a grant with the University of Georgia 1935-42000-057-03G "Predictive Models for Thermal Inactivation of Listeria Mnocytogenes on the Surface of Hot Dogs." A General Assistance Grant with Purdue University. 1935-42000-0570-04G "Transfere Coefficients for L. Monocytogenes to and from food contact surfaces found in meat fabrication facilities."A General Assistance Grant with Michigan University. 1935-42000-057-05R - "HACCP Assistance for Small and Very Small Processors with Development and Validation of meat chilling Rates." A Reimbursable Agreement with University of Nebraska.1935-42000-057-07R - "HACCP Training and Research to Assist Meat Processors with Process Deviations for Lethality and Stabilization." A Reimbursable Agreement with the University of Nebraska. 1935-42000-057-08R - "HACCP Assistance for Small and Very Small Meat Processors: Challenge Studies and Predictive Modeling for Validation of Critical Limits." A Reimbursable Agreement with the University of Wisconsin. 1935-42000-057-09R - "An Internet-Based Portal to Assist Small and Very Small Food Processors in Meeting Food Safety Regulations." A Reimbursable Agreement with Food Safty & Inspection Service (FSIS), USDA. 1935-42000-10R - "Study on Survivability of Yersinia Pestis and Bacillus Anthracis in Raw and Cooked Ground Beef." A Reimbursable Agreement with the Food Safety and Inspection Service (FSIS), USDA. 1935-42000-057-11S - "Acetate, Lactate, and Diacetate Levels in RTE Processed Meat & Poultry Products Collected At Retail & Correlation with Occurrence of L. Mono." A Specific Cooperative Agreement with the University of Tennessee. 1935-42000-057- 12S "Listeria Monocytogenes Contamination of Deli Meat Slicers: Risk and Communication." A Specific Cooperative Agreement with Michigan State. 1935-42000-057-13S - "An Internet-Based Predictive Microbiology Portal to Assist Small and Very Small Food Processors in Meeting Food Safety Regulations." A Specific Cooperative Agreement with Rutgers University. 1935-42000-057-14S - "Construction and Characterization of Reporter Strains for the Identification of Physiochemical Parameters Influencing... of Escherichia Coli." A Specific Cooperative Agreement with the University of Wisconsin. 1935-42000-057-15N - "Transfer of Listeria Monocytogenes Among Salmon and Slicing Machines. A Geneal Assistance Grant with VTT Echnical Research Center - Finland. 1935-42000-057-16G - "Support for the International Conference On Microbial Risk Assessment (PA06-15)." A General Assistance type of Agreement between ARS Office of Technlogy Transfer. Additional details can be found in the specific reports for these agreements. The agreements were monitored via regular meetings, emails or conference calls. Accomplishments Safe time/temperature for cooling of cooked foods. Improper storage and/or inadequate cooling practices in retail food operations have been cited as the cause of food poisoning for 97% of Clostridium perfringens outbreaks. Mathematical models were developed to predict the relative growth of C. perfringens from spores at temperatures applicable to the cooling of cooked uncured chicken. The growth data /predictive models on the safe cooling rate of meat will enable the food industry to assure that cooked products remain pathogen-free. The research is relevant to Component 1.2 (Pathogen Reduction Postharvest), Problem Statement 1.2.7 (Risk Assessment), in the 2006-2010 NP 108 Action Plan. Behavior of L. monocytogenes in Cooked Ham Containing Lactate and Diacetate. The effect of lactate and diacetate on L. monocytogenes in ham at temperatures that the product is likely to be exposed to during manufacturing and distribution is lacking. Predictive model describing the behavior of L. monocytogenes in ham containing sodium lactate (1.0-4. 2%) and sodium diacetate (0.05-0.2%) at storage temperatures of 0�-45�C were developed. The model elucidates the effects of both additives and storage temperature on L. monocytogenes, and enables the producers to select the concentrations of lactate and diacetate that are able to control the growth of L. monocytogenes in ham products. The research is relevant to Component 1.2 (Pathogen Reduction Postharvest), Problem Statement 1.2.7 (Risk Assessment), in the 2006-2010 NP 108 Action Plan. Microbiological Safety of Fermented Sausages. The use of raw meat in the manufacturing of fermented dry and semidry sausage may introduce L. monocytogenes and Salmonella spp into the finished product. Understanding the survivability of both pathogens in sausage during the manufacturing processes allows processing/product parameters be selected to minimize the presence of both pathogens in finished products. Studies conducted to collect the inactivation data of L. monocytogenes and S. typhymurium in sausage were completed. Models were developed to describe the rates of inactivation of both pathogens during sausage manufacturing. The results will be used by the manufacturers to determine the process/product parameters to meet the food safety requirement. The research is relevant to Component 1.2 (Pathogen Reduction Postharvest), Problem Statement 1.2.7 (Risk Assessment), in the 2006-1010 NP 108 Action Plan. Transfer of E. coli O157:H7 during mechanical slicing of deli meats. Food safety managers currently lack the ability to predict the microbial pathogen transfer in slicing operation for ready-to-eat foods. Models were developed for pathogen transfer prediction during mechanical slicing for RTE deli meats. Predictive models will be useful in developing HACCP plans and in risk assessment development for ready-to-eat meats. By understanding the surface transfer, the production or retail (Franchise) equipment and operations for RTE deli meat may be further improved and therefore, reduce the possibility of outbreaks. Finally, the models will be available through the PMP and ComBase. The research is relevant to Component 1.2 (Pathogen Reduction Postharvest), Problem Statement 1.2. 7 (Risk Assessment), in the 2006-2010 NP 108 Action Plan. Expression of 70-kb virulence plasmid (pYV/pCD) phenotypes in Yersinia species. Risk assessors in food safety management need to predict the fate of Yersinia pestis for scenarios where bulk foods could be contaminated, thereby exposing a relatively large number of individuals. Therefore, diagnostic markers were developed to predict the growth of Y. pestis and Y. pseudotuberculosis in ground beef and ground pork. This accomplishment addressed on the phenotypic expression of the 70-kb virulence plasmid (pYV/pCD)-associated genes in Yersinia pestis and Y. pseudotuberculosis. The pYV/pCD-encoded phenotypes expressed can be used as virulence markers for detection of these pathogens in foods. This will assist the government risk assessor and food companies in detecting and determining the fate of Y. pestis in contaminated foods, thus improve exposure assessment and aid in designing more effective food safety controls. The research is relevant to Component 1.2 (Pathogen Reduction Postharvest), Problem Statement 1.2.7 (Risk Assessment) and 1.2.9 (Food Security), in the 2006-2010 NP 108 Action Plan. Significant Activities that Support Special Target Populations Collaborated with a small producer of fermented sausage named Mediterranean Foods, a company with 2 employees and an annual sale of less $200,000, located in Upper Darby, Pennsylvania, to examine the behavior of E. coli O157:H7, Salmonella, and L. monocytogenes on fermented, semi-dry sausage introduced by post-processing contamination. The producer provides finished commercial products, and ARS conducts the challenge study. Technology Transfer Number of Web Sites managed: 3 Number of Non-Peer Reviewed Presentations and Proceedings: 9

Impacts
(N/A)

Publications

  • Velugoti, P.R., Lalit, B.K., Juneja, V.K., Thippareddi, H. 2007. Inhibition of germination and outgrowth of clostridium perfringens spores by lactic acid salts during cooling of cooked ground turkey. Journal of Food Protection. 70:923-929.
  • Juneja, V.K., Friedman, M. 2007. Carvacrol, cinnamaldehyde, oregano oil, and thymol inhibit clostridium perfringens spore germination and outgrowth in ground turkey during chilling. Journal of Food Protection. 70:218-222.
  • Hwang, C., Marmer, B.S. Growth of listeria monocytogenes in egg salad and pasta salad formulated with mayonnaise of various ph and stored at refrigerated and abuse temperatures. Food Microbiology. 24:211-218.
  • Juneja, V.K., Melendres, M.V., Huang, L., Gumudavelli, V., Subbia, J., Thippareddi, H. 2007. Modeling the effect of temperature on growth of salmonella in chicken. Food Microbiology. 24:328-335.
  • Oscar, T.P. 2007. Predictive model for growth of salmonella typhimurium dt104 from low initial and high initial density on ground chicken with a natural microflora. Food Microbiology. 24:640-651.
  • Juneja, V.K., Bari, L.M., Inatsu, Y., Kawamoto, S., Friedman, M. 2007. Control of Clostridium perfringens Spores by Green Tea Leaf Extracts During Cooling of Cooked Ground Beef, Chicken, and Pork. Journal of Food Protection. 70(6):1429-1433.


Progress 10/01/05 to 09/30/06

Outputs
Progress Report 1. What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? Why does it matter? Each year, it is estimated that more than 76,000,000 infections are linked to the consumption of contaminated foods, with an associated 5,000 deaths and an economic impact exceeding $5,000,000,000 USD. Such contamination can occur at many points in the food production system, on the farm, at processing plants, during transportation, at wholesale and retail levels, and during consumer handling. Fortunately, the risk of foodborne disease can be reduced by designing and implementing food processing and handling interventions that control, reduce and/or eliminate foodborne pathogens. Regulatory agencies, such as the Food & Drug Administration (FDA) and the USDA Food Safety & Inspection Service (FSIS), utilize quantitative microbial risk assessment (QMRA) to determine interventions that provide the most effective means of reducing the risk of foodborne disease. In the food industry, such interventions are part of Hazard Analysis & Critical Control Points (HACCP) food safety systems. However, the scientific and fiscal resources needed to determine the appropriate critical points and associated safe processing parameters many times exceed the resources of food companies, especially that of small and very small FSIS-inspected operations. For these reasons, predictive models present efficient solutions to the development of HACCP plans and in the production of risk assessment, thus permitting risk managers to estimate the behavior of pathogens over a wide range of diverse processing and handling conditions. This project solves many of these problems by providing models that describe the behavior of major pathogens in higher risk marketplace foods, including scenarios for pathogen growth, virulence expression, death and transfer among food processing surfaces. Furthermore, we will decrease the uncertainty of model predictions by identifying cellular markers associated with the physiological state of the pathogen and thus the length of the bacterial lag phase. To enhance the transfer of these technologies, we will measure the bias and accuracy of models and describe their performance for various categories of foods, thereby assisting food industries and risk assessors in determining which modeling tools best meet their needs. This will facilitate the use of more models in HACCP systems and lead to greater acceptance of models by regulators and the food industry. We anticipate that the development of these new models into a process model format will also accelerate their integration into HACCP operations, allowing users to estimate the effects of various interventions throughout a series of food processing operations. The specific objectives for this project are 1) to evaluate, validate, and where necessary, develop new innovative, robust and valid predictive models for the responses of microbial pathogens, including foodborne threat agents, in select food matrices, as a function of: temperature, food formulation, competitive microflora, physiological history, and surface transfer, 2) to develop novel approaches to assess model performance and robustness, leading to more efficient strategies for producing and extrapolating models to different classes of food, and 3) to determine the probability distribution of lag phase duration (LPD) for foodborne pathogens, as a function of the previous bacterial physiological history, to and identify molecular markers that discriminate bacterial lag, growth and stationary phases. The proposed research is relevant to Sections 1.2.7 (Risk Assessment) and 1.2.9 (Food Security) in the 2006-2010 NP 108 Action Plan. The proposed work addresses ARS research priorities for improved QMRA through more accurate exposure assessment and risk characterization; for development of robust and validated process risk models that address hazards in complex food matrices; and for validated models that predict the effect of specific intervention strategies on threat agents. Furthermore, the project plan will result in user-friendly simulation models which will be used by industry and regulatory agencies to assess the impact of foodborne pathogens on public health. 2. List by year the currently approved milestones (indicators of research progress) FY 2006 Complete prototype ground beef microbial community model. Complete data collection for growth of Yersinia spp. in ground beef and pork Complete measurements of E. sakazakii LPD Complete E. coli O157:H7 - fermented sausage models Complete a model for the inactivation of B. anthracis and L. monocytogenes in ground beef, and model for the fate of C. perfringens during the cooling of uncured beef Complete measurements of E. coli O157:H7 surface transfer coefficients Complete robustness indices (RI) for E. coli in beef Complete E. sakazaki infant formula growth model FY2007 Complete prototype ham microbial community model Complete data collection for Yersinia spp. plasmid stability in ground beef and pork Complete E. coli O157:H7 LPD distribution models Complete models of L. monocytogenes, Salmonella in fermented sausage; L. monocytogenes in ham and meat salad Complete production of a predictive model for thermal inactivation of E. coli O157:H7 in beef and a model of C. perfringens growth applicable to the cooling of uncured pork. Complete studies of L. monocytogenes transfer Complete measurements of RI for Salmonella in beef Complete E. sakazaki data collection for survival in dry infant dry formula FY2008 Produce models for microbial competition in ground beef and ham Transfer Yersinia spp. models to PMP and ComBase Complete probability distribution models for L. monocytogenes LPD Complete identification of E. coli K12 DNA LPD markers Complete models of L. monocytogenes in smoked seafood Complete models of C. perfringens survival during cooling of cooked poultry Complete measurements of Salmonella surface transfer coefficients Complete RI for L. monocytogenes in deli meats and salads Complete E. sakazaki consumer practice LPD models FY2009 Validate models Complete analyses of RNA markers Validate fermented sausages, smoked seafood and meat/ham salad models Complete studies of Salmonella inactivation, and survival during cooling and storage Validate Salmonella, E. coli and L. monocytogenes models Complete translation of model uncertainty into exposure levels Transfer models via PMP and ComBase FY2010 Transfer models via PMP and ComBase Complete analyses of protein markers Validate models and transfer models via PMP and ComBase Complete process risk mode, transfer models to PMP and ComBase Transfer models to PMP 4a List the single most significant research accomplishment during FY 2006. This project recently completed the NP 108 OSQR Review Process and was certified. See the report for 1935-42000-050-00D. 4b List other significant research accomplishment(s), if any. This project recently completed the NP 108 OSQR Review Process and was certified. See the report for 1935-42000-050-00D. 4c List significant activities that support special target populations. This project recently completed the NP 108 OSQR Review Process and was certified. See the report for 1935-42000-050-00D. 4d Progress report. 1935-42000-057-01G: This report serves to document research conducted under a General Assistance Type agreement between ARS and the University of Arkansas. There is a great need for validated models to predict the thermal inactivation of L. monocytogenes and to assist the food industry in implementing in-plant heat pasteurization of packaged, fully cooked poultry and meat products. Researchers at the University of Arkansas and the ARS Eastern Regional Research Center in Wyndmoor, PA are validating a predictive model of heat and mass transfer with pathogen kinetics to predict pathogen kill as a function of time, moisture, and temperature, and designing treatment schedules to achieve the targeted pathogen log- reduction on various sizes and shapes of poultry products that are processed in different commercial steam or hot water cookers, followed by cooling. The research products support the Project Plan and will result in more accurate thermal food processes to minimize risks caused by L. monocytogenes. 1935-42000-057-02G: This report serves to document research conducted under a General Assistance Type of agreement between ARS and the University of Georgia. The doses of L. monocytogenes that result in human listeriosis are not known, primarily because human experimental studies cannot be conducted. Researchers at the University of Georgia and the ARS Eastern Regional Research Center in Wyndmoor, PA are using pregnant guinea pigs to develop dose response information for L. monocytogenes- induced human stillbirths and/or abortions. This will be done by 1) determining the region of dose-response overlap with the existing non- human primate study, 2) determining the dose-response for adverse fetal effect after maternal exposure to L. monocytogenes, 3) defining endpoints that predict adverse pregnant outcomes such as L. monocytogenes invasion of maternal liver, maternal spleen, placenta and fetus, and 4) comparing the dose response curve developed in pregnant guinea pigs to mouse, primate and human dose response curves. This research supports the Project plan by producing dose response models that more accurately estimate infective doses of L. monocytogenes. 1935-42000-057-03G: This report serves to document research conducted under a General Assistance type of agreement between ARS and Purdue University. Researchers at Purdue University and the ARS Eastern Regional Research Center in Wyndmoor, PA are developing realistic and accurate predictive models for the thermal inactivation of L. monocytogenes in processed RTE meats. This will be accomplished by studying and comparing thermal inactivation models for L. monocytogenes grown under stress conditions in low and high fat hot dogs (10 to 30%), in conditions to simulate its presence in water and residual sanitizers, and in tryptic soy broth. This will be done by 1) comparing surface thermal inactivation models over a range of post-processing temperatures relevant to industrial practices for L. monocytogenes in hot dogs made with and without combinations of sodium diacetate and potassium lactate as currently used in the industry, 2) by determining thermal inactivation of L. monocytogenes on hot dogs surface-sprayed with different combinations of sodium diacetate and potassium lactate, and 3) by validating the new models against the experimental data for inactivation of L. monocytogenes in hot dogs using the growth medium that represents high and low D-values and sprayed lactate/diacetate formulations. This research supports the Project Plan by producing technologies that can be transferred to food companies, food regulators and risk assessors to design more effective processing controls to minimize the risks of listeriosis. 1935-42000-057-04G: This report serves to document research conducted under a General Assistance type of agreement between ARS and Michigan State University. Little is known about the effects of temperature and relative humidity on growth and die-off of L. monocytogenes on high density polyethylene (HDPE) and polyurethane (PU) conveyor belt surfaces used in processing plants. Researchers at Michigan State University and the ARS Eastern Regional Research Center in Wyndmoor, PA are assessing the impact of food contact material, inoculum level, product moisture content, contact time and contact pressure on transfer coefficients for L. monocytogenes from surface-contaminated hams to HDPE and PU and vice versa, determine a series of transfer coefficients for L. monocytogenes from inoculated HDPE and PU contact surfaces to ham and vice versa, and develop a mathematical model based on data from the previous objectives that will express and quantify transfer potentials for listeria cross contamination within the food processing environment. This research supports the Project Plan by producing process risk models that can be transferred to food companies, regulators and risk assessors to predict the movement of pathogens among food processing surfaces. 1935-42000-057-05R: This report serves to document research conducted under a Reimbursible Cooperative Agreement between ARS and the University of Nebraska. Funds were received for research on developing and validating models during cooking and cooling of cooked products. In order to carry out the research, studies were conducted under 1935-42000- 057-00 D to determine the growth of C. perfringens in 75% lean beef, pork and poultry at various temperatures ranging from 10C to 50C. Collection of data was completed and a predictive model for the disposition of products subject to cooling deviations was developed. The model will be incorporated in the ARS-Pathogen Modeling Program. 1935-42000-057-07R: This report serves to document research conducted under a Reimbursible Cooperative Agreement between ARS and the University of Nebraska. Funds were received for research on developing and validating models during chilling of carcasses. In order to carry out the research, studies were conducted under 1935-42000-057-00 D to model the effect of temperatures on growth of Salmonella in beef and chicken at various temperatures ranging from 5C to 50C. Two predictive models applicable to the chilling of meat animal carcasses have been developed. These models will be incorporated in the ARS-Pathogen Modeling Program. 1935-42000-057-08R: This report serves to document research conducted between ARS and the University of Wisconsin. Validated predictive models for pathogen growth in meat and poultry products are not available. Researchers at the University of Wisconsin and the ARS Eastern Regional Research Center in Wyndmoor, PA integrate research in three areas: short- term temperature abuse of uncooked meat and poultry products, slow- cooking and/or fermentation of meat and poultry products, and low-heat processing of ready-to-eat meat and poultry products. The research product support the CRIS project plan and will provide data to meet Critical Limit validation needs of meat and poultry processors for use in validation and verification of their HACCP plans. 1935-42000-057-09R: This report serves to document research conducted under a Reimbursable agreement between ARS and USDA Food Safety Inspection Service. Predictive models allow food safety managers to forecast the fate of pathogens in food processing operations, however many small and very small processors require additional support in the use and interpretation of models. The FSIS Division of Outreach and Strategic Partnerships in Washington, DC and the ARS Eastern Regional Research Center in Wyndmoor, PA are developing a Predictive Microbiology Information Portal that provides on-line models, research data and background information for food safety applications. This research supports the Project Plan by enhancing the transfer of predictive microbiology technology to food companies for use in food safety management. 1935-42000-057-10R: This report serves to document research conducted under a Reimbursable Cooperative agreement between ARS and USDA Food Safety and Inspection Service. Behavior of Yersinia pestis in raw and cooked ground beef and Bacillus anthracis Sterne in cooked ground beef were characterized. The thermal resistance (D-values in min) of Y. pestis in ground beef ranged from 37.9 min at 50 degree C to 1.1 min at 57.5 degree C (z = 8.7 degree C). Cooking ground beef patties inoculated with B. anthracis on a gas grill to an internal temperature of 71.1 degree C resulted in pathogen reduction from 5.7 to 2.9 log10 CFU/g. This study provided an understanding on how such threat agents behave in beef when intentional contamination could cause widespread human exposure. Predictive models allow risk managers to estimate the probability of human exposure to these pathogens following the ingestion of potentially contaminated ground beef. This research supports the CRIS Project Plan by enhancing information provided by predictive models that are used in food safety management. 1935-42000-057-11S: This report serves to document research conducted under a Specific Cooperative Agreement between ARS and the University of Tennessee. There are not data that demonstrate the prevailing levels of lactate, acetate, or diacetate in retail RTE deli meat and their correlation to the occurrence of L. monocytogenes in these products. Researchers at the University of Tennessee and the ARS Eastern Regional Research Center in Wyndmoor, PA quantify the levels of acetate, lactate, and diacetate occurring in retail RTE processed deli meat and poultry products previously analyzed for L. monocytogenes to determine the impact of current antimicrobial lethality treatments on occurrence of L. monocytogenes at retail. The research product support the project plan and will provide data needed by the Food Safety and Inspection Service (FSIS) on the uniformity and levels of organic acids occurring in RTE processed meat and poultry products following implementation of the Listeria Rule in late 2003. 1935-42000-057-12S: This report serves to document research conducted under a Specific Cooperative agreement between ARS and the Michigan State University. MSU conducted the Listeria transfer using mechanical slicer and RTE deli meat with consideration of different knives, product compositions (e.g. fat content), and etc. MSU proposed to develop the transfer model using an experimental design. The most significant accomplishments to date include: (1) acquisition of four model 2612 Hobart slicers, (including three types of blades) as well as one Berkel slicer (donated by Berkel) that was recently re-designed for enhanced cleanability; (2) the set up the three Hobart slicers and the Berkel slicer at a local delicatessen for one year of use and monthly sampling; (3) identification of the product contact areas on the slicers for sampling; (4) optimization of the blade inoculation method using surface- inoculated ham; and (5) collection of initial data on the potential and extent for sequential transfer of L. monocytogenes from the slicer blade to ham and other areas of the slicer during slicing. We have contributed the measurement of the blade surface profiling of brand new blades and delivered the blades to MSU. All the blades will be re- profiled after one year use. The blade surface character is one of the key parameters to be used by MSU for model development. 1935-42000-057-13S: This report serves to document research conducted under a Specific Cooperative agreement between ARS and Rutgers University. Predictive models allow food safety managers to forecast the fate of pathogens in food processing operations, however many small and very small processors require additional support in the use and interpretation of models. Rutgers University in New Brunswick, NJ and the ARS Eastern Regional Research Center in Wyndmoor, PA are developing a Predictive Microbiology Information Portal that provides on-line models, research data and background information for food safety applications. This research supports the Project Plan by enhancing the transfer of predictive microbiology technology to food companies for use in food safety management. 1935-42000-057-14S: This report serves to document research conducted under a Specific Cooperative agreement between ARS and University of Wisconsin. Understanding the risk of foodborne pathogens includes knowing conditions that cause the expression of virulence factors in food. Researchers at the University of Wisconsin in Madison, WI and the ARS Eastern Regional Research Center in Wyndmoor, PA are developing "reporter" strains of pathogenic E. coli O157:H7 that can be used to measure the expression of virulence factors under real food handling conditions. This research supports the Project Plan by enhancing information provided by predictive models that are used in food safety management. 1935-42000-057-15N: This report serves to document research conducted under a Non-Funded Cooperative agreement between ARS and Technical Research Centre of Finland. The Listeria transfer data between a slicer and gravad salmon were collected in the ERRC Lab, Microbial Food Safety Research Unit located at Wyndmoor, PA. The experimental data involved different operation temperature, inoculum levels, cross-contamination steps and etc. The studies showed that "empirical" model(s) for Listeria cross-contamination transfer prediction can be developed and applied to operations (with similar conditions). The model(s) may be affected by many other operation conditions and/or physical properties of salmon, therefore, further studies will be needed. 1935-42000-057-16G: This report serves to document research conducted under a General Assistance type of agreement between ARS and the AS Institute Food Science and Technology. Professional activities funding was used to attend and to support the International Conference on Microbial Risk Assessment: Foodborne Hazards held in Sydney, Australia, on February 21-23, 2006. This meeting provided a forum for risk analysts and food safety researchers to discuss the implementation of microbial risk assessment. High priority research objectives for further study that will appreciably aid regulators in drafting science-based policies and aid the industry on enhancing the wholesomeness of foods were identified. Factors that have impeded the implementation of risk assessment and the strategies for accelerating their use in establishing Acceptable Levels of Protection, Food Safety Objectives and Performance Objectives against foodborne hazards were discussed. The products of this conference support the CRIS Project by aiding scientists in more effectively interfacing with food industry in adopting and implementing food processing performance criteria that control microbial hazards. 5. Describe the major accomplishments to date and their predicted or actual impact. This project recently completed the NP 108 OSQR Review Process and was certified. See the report for 1935-42000-050-00D. 6. What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end- user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products? This project recently completed the NP 108 OSQR Review Process and was certified. See the report for 1935-42000-050-00D. 7. List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: List your peer reviewed publications below). This project recently completed the NP 108 OSQR Review Process and was certified. See the report for 1935-42000-050-00D.

Impacts
(N/A)

Publications