Progress 09/15/02 to 09/14/07
Outputs
OUTPUTS: This project involved extension, research and teaching efforts directed at bioterrorism risks in the fresh and fresh-cut produce industries. An auditing tool was developed and tested for use in food security evaluation programs. In 2003 and 2004, onsite auditing of commercial produce operations in Georgia, South Carolina and Florida was conducted to evaluate their food security and bioterrorism readiness programs. The food security audit form aided Extension personnel and the private sector in evaluating the readiness of commercial operations in the area of food defense. The comprehensive form was relatively easy to use. Information gained was incorporated in training workshops. During 2005, one-half day trainings on biosecurity for the produce industry were developed. These trainings were incorporated into existing GAP training programs for the fresh produce industry and into HACCP training programs for the fresh-cut industry in 2005-2007. Material covered included the
importance of food biosecurity, impact on the produce industry, development of biosecurity plans, and breakout activities focusing on biosecurity risk analysis and planning. The biosecurity training was the first of its kind for workshop participants and was well received. An undergraduate college course was developed and offered in 2005 and 2007 focusing on the security of the U.S. food supply. The class examined issues facing the food industry and current activities of the industry and governmental agencies aimed at protecting our food supply. During 2006, two separate workshops to train Extension agents from Georgia, South Carolina and Florida in food defense planning were developed and offered. A "train the trainer" curriculum was developed and distributed to Extension personnel for use with produce producers and fresh-cut produce processors. Abbreviated versions of the training were offered in two industry workshops. The programs included sections on the CARVER+Shock risk
analysis with exercises to simulate real life situations. Food defense lectures and exercises were incorporated into two departmental courses, food laws and food microbiology. A consumer website was developed and includes information on produce safety and food defense (www.fcs.uga.edu/ext/fdn/produce_safety). Using non-pathogenic surrogates in place of pathogens when conducting a risk assessment of commercial food processing operations offers safety advantages, but surrogates must exhibit characteristics similar to the pathogen. Characteristics of some non-pathogenic E. coli strains were compared with E. coli O157:H7. A non-pathogenic strain with similar properties as E. coli O157:H7 was identified and used in studies involving attachment and recoverability of the pathogen from chilled produce and also in studies involving contaminated ice in contact with fresh produce. Botulinum neurotoxins may be a potential agent of bioterrorism. Little information exists regarding the stability of
this toxin on fresh produce. Research was conducted to determine the stability of Clostridium botulinum neurotoxin on fresh produce at varying pH and temperature levels.
PARTICIPANTS: Mark A. Harrison, PI, University of Georgia, William C. Hurst, Co-PI, University of Georgia, Judy A. Harrison, Co-PI, University of Georgia, Karen Simmons, Program Specialist, University of Georgia, Ruth Ann Morrow, Research Professional, University of Georgia, Robin Salinsky Broeker, Graduate Research Assistant, University of Georgia, Deann Akins, Graduate Research Assistant, University of Georgia, Worawut Rakiti, Graduate Research Assistant, University of Georgia, Jinkyung Kim, Graduate Research Assistant, University of Georgia, Jacob Polsky, Graduate Research Assistant, University of Georgia, Jeffrey Brecht, Co-PI, University of Florida, Keith R. Schneider, Co-PI, University of Florida, Amy Simonne, Co-PI, University of Florida, James W. Rushing, Co-PI, Clemson University, Joseph Ferreira, Partnership Investigator, formerly with FDA, Atlanta, GA
TARGET AUDIENCES: Target Audiences and Effort: Onsite auditing of fresh and fresh-cut production facilities - Total facilities audited included 25 farms, 25 packing facilities, and 6 fresh-cut facilities. Train-the-trainers Workshops - 2 workshops held with approx 25 County Extension Agents from GA, SC, and FL attending. Industry Workshops - Representatives from the fresh and fresh-cut produce industry participated in 4 half day programs with a total of 90 participants. College coursework at the University of Georgia - A new course was developed for undergraduates and offered twice to a total of 30 students. Material was incorporated into 2 existing courses and offered to approx. 115 students over the past 3 years. Consumer website - Website is available to anyone with web access. Research information - Results are available to the scientific community through meeting presentations and publications.
Impacts
Results from industry surveys indicated there was some degree of awareness by commercial operators related to biosecurity and bioterrorism. The degree of awareness varied, however, between packinghouses and fresh-cut processing facilities. Fresh-cut operations seemed to be more aware of the need for security planning than small packinghouse operations. As customers are requiring more proof of safe food products from the packers, we noted that the small packers were becoming more interested in incorporating security practices in their operations. Upon follow-up with survey participants, it was determined that some growers and packers had either instigated or intended to instigate more stringent security practices than were previously in place. Information gained from the audits conducted at fresh produce packers and fresh-cut produce processors was incorporated into training workshops. The workshop segments on food defense and risk assessment were the first exposure for
Extension agents and industry representatives to the CARVER+shock risk assessment tool. The risk assessment breakout exercises were well-received by participants and stimulated much food defense dialogue concerning differing security situations. Undergraduate students were presented with situations that could occur in the fresh produce industry and were assigned the task of determining the risk and possible mitigation strategies. A table top exercise simulating a foodborne illness outbreak was conducted with students responding from the perspective of retailers, suppliers or representatives of appropriate governmental agencies. Students were also introduced to biosecurity laws and regulations. Course evaluations at the end of the course indicated a greater awareness of the subject and the challenges presented in guarding the food supply against attack. By evaluating the selection of a surrogate under environmental conditions that mimic actual conditions, it was determined that E. coli
ATCC 25922 is a suitable E. coli O157:H7 surrogate for risk assessment studies involving pathogen attachment and recoverability from chilled, fresh produce. The study determined the effect of starvation on attachment of E. coli O157:H7 and a surrogate E. coli ATCC 25922 to lettuce. Overall E. coli ATCC 25922 survived starvation to a greater degree and exhibited greater cryotolerance than E. coli O157:H7. There were few differences in outer membrane protein patterns among starvation conditions. Starved cells of both strains attached to lettuce less than non-starved cells. After contact with ice and water contaminated with each strain, attachment and recoverability from romaine lettuce of E. coli ATCC 25922 was similar to that of E. coli O157:H7. E. coli ATCC 25922 proved to be a useful surrogate for E. coli O157:H7 for studies involving fresh, chilled produce. The botulinal toxin studies revealed that the inherent produce enzymes, produce maturity, and water loss may contribute to
toxin stability on produce surfaces and that toxin stability may vary based on the type of produce, the storage temperature and the pH of the toxin suspension.
Publications
- Akins, E. Deann, Mark A. Harrison and William C. Hurst. 2007. Effect of washing practices on the microflora on Georgia-grown cantaloupes. J. Food Prot. In Press.
- Kim, Jinkyung and Mark A. Harrison. 2007. Transfer of Escherichia coli O157:H7 to romaine lettuce due to contact water from melting ice. J. Food Prot. In Press.
- Kim, J. and Harrison, M.A. 2007. Starvation Effect on Attachment Properties of Escherichia coli O157:H7 and a Non-pathogenic Surrogate E. coli. Annual Meeting of the International Association for Food Protection. Orlando, FL. #P5-14. Pg. 227.
- D'Sa, E. M., Andress, E. A., Harrison, J. A., and Harrison, M. A. 2007. Survey of home canning practices and safety issues in the U. S. Annual Meeting of the Institute of Food Technologists. Presentation # 005-04
- Kim, Jinkyung. 2007. Transfer of Escherichia coli O157:H7 to romaine lettuce during ice storage and evaluation of E. coli ATCC 25922 as its surrogate. Ph.D. Dissertation, University of Georgia
- Simmons, Karen, Mark A. Harrison, William C. Hurst, Judy A. Harrison, Jeffery Brecht, Keith Schneider, Amy Simonne, and James Rushing. 2006. Safety and Security - Research Looks at Security Practices of Southeast Produce Operations. Fresh Cut Magazine. 14(4):40-45.
- Simmons, Karen, Mark A. Harrison, William C. Hurst, Judy A. Harrison, Jeffery Brecht, Keith Schneider, Amy Simonne, and James Rushing. 2007. Survey of food defense practices in produce operations in the southeast. Food Protect. Trends. 27(3):174-184.
- Milly, P. J., R. T. Toledo, M. A. Harrison, and D. Armstead. 2007. Inactivation of food spoilage microorganisms by hydrodynamic cavitation to achieve pasteurization and sterilization of fluid foods. J. Food Sci. 72:M414-M422.
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Progress 01/01/06 to 12/31/06
Outputs
During 2006, two separate workshops to train Extension Agents from Georgia, South Carolina, and Florida in food defense planning for fresh and fresh-cut produce industries were developed and offered. In addition, abbreviated versions of the training were offered in two industry workshops. The programs included sections on the CARVER+Shock risk analysis with exercises to provide simulated real life situations. In addition to the professional trainings offered, food defense lectures and exercises were incorporated into two departmental courses, food toxicology and food microbiology. Students were presented with situations that could occur in the fresh produce industry and were assigned the task of determining the risk and possible preventative programs to implement. Intentional contamination of fresh produce due to pathogen-contaminated ice is possible. This threat can be evaluated to some degree under laboratory conditions using pathogens like Escherichia coli O157:H7.
However, in actual food packing or processing facilities evaluations using pathogens is undesirable. If suitable non-pathogenic surrogates are available, then they could be used. In the previous reporting period, a possible surrogate for E. coli O157:H7 was selected from a pool of possibilities. E. coli O157:H7 can survive in water for extended periods which can induce starvation stress on the cells. Starvation stress may enhance E. coli O157:H7 survival under subsequent stresses by changing surface morphology which may affect adherence to produce. The study determined the effect of starvation on attachment of E. coli O157:H7 and a surrogate E. coli ATCC 25922 to lettuce. Overall E. coli ATCC 25922 survived starvation to a greater degree and exhibited greater cryotolerance than E. coli Ol57:H7. Hydrophobicity of both strains decreased over 7 d storage and zeta potential of E. coli ATCC 25922 was more consistent than E. coli O157:H7. There were few differences in outer membrane protein
patterns among starvation conditions. Microscopically, starved cells of both strains appeared elongated, wrinkled and malformed. Starved cells of both strains attached to lettuce less than non-starved cells. Top icing of fresh lettuce is needed to prevent moisture loss from the surface of product in a refrigeration unit during transportation. It was determined that E. coli ATCC 25922 could serve as a possible surrogate for E. coli O157:H7 involving attachment to romaine lettuce after contact with contaminated ice under simulated commercial operation conditions. Recovery rates from lettuce surfaces for E. coli O157:H7 and E. coli ATCC 25922 were compared. Water containing each strain was frozen and used to ice lettuce in shipping containers at refrigeration temperature (4 C) to represent lettuce transportation. After the ice melted, samples were taken and attachment and recoverability of the E. coli strains after washing with chlorinated water (200 ppm free chlorine) were determined.
E. coli ATCC 25922 attachment to and recoverability from romaine lettuce was similar to that for E. coli O157:H7 under simulated commercial operation condition.
Impacts
Thirty-seven Extension agents and 34 industry representatives were trained during the workshops. This was their first exposure to the CARVER+Shock assessment program. Material provided to them should allow them to address questions raised by fresh and fresh-cut produce producers and processors. Over forty undergraduate and graduate students were exposed to food defense through formal university coursework. They were introduced to the biosecurity laws and regulations as well as food defense assessment programs. By evaluating the selection of a surrogate under environmental conditions that mimic actual conditions, it was determined that E. coli ATCC 25922 is a useful surrogate for E. coli O157:H7 for attachment and recoverability studies from chilled, fresh produce.
Publications
- Bauer-Garland, J., Frye, J.G., Gray, J.T., Berrang, M.E., Harrison, M.A., and Fedorka-Cray, P.J. 2006. Transmission of Salmonella enterica serotype Typhimurium in poultry with and without antimicrobial selective pressure. J. Appl. Microbiol. 101:1301-1308.
- Son, I., Englen, M.D., Berrang, M.E., Fedorka-Cray, P.J., and Harrison, M.A. 2006. Genetic diversity of Arcobacter and Campylobacter on broiler carcasses during processing. J. Food Prot. 69:1028-1033.
- Chambliss, S., Narang, N., Juneja, V.K., and Harrison, M.A. 2006. Thermal injury and recovery of Salmonella Enteritidis in ground chicken with temperature, pH and sodium chloride as controlling factors. J. Food Prot. 69:2058-2065.
- Musgrove, M.T., Harrison, M.A., Fedorka-Cray, P.J., Ladely, S.R., Jones, D.R., Northcutt, J.K., and Cox, N.A. 2006. Antimicrobial Resistance in Salmonella and Escherichia coli Isolated from Commercial Shell Eggs. Poultry Sci. 85:1665-1669.
- Reimer, Nancy A. 2006. Pathogen inactivation on beef jerky in a commercial-type dehydrator under various moisture conditions. Ph.D. Dissertation, University of Georgia. 47 pgs.
- Rakiti, Worawut. 2006. Antimicrobial intervention and process validation in beef jerky processing. M.S. Thesis, University of Georgia. 62 pgs.
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Progress 01/01/05 to 12/31/05
Outputs
This project is a collaborative effort within Georgia, South Carolina and Florida involving extension, research and teaching efforts directed at the bioterrorism risks faced by the fresh and fresh-cut produce industries. Fresh produce is grown, harvested and packed literally in the open and there is typically no kill step to destroy microbial pathogens prior to consumption which makes it potentially vulnerable to tampering. During 2005, outreach efforts included the development of one-half day trainings on biosecurity for the produce industry. These trainings were incorporated into existing GAP training programs for the fresh produce industry and into HACCP training programs for the fresh-cut industry. Material covered included the importance of food biosecurity, impact on the produce industry, development of biosecurity plans, and breakout activities focusing on biosecurity risk analysis and planning. In addition, an undergraduate college course was developed and
offered in fall 2005 focusing on the security of the U.S. food supply. The class examined issues facing the food industry and the current activities of the industry and governmental agencies aimed at protecting our food supply. Using non-pathogenic surrogates in place of pathogens when evaluating commercial food processing operations offers safety advantages, but surrogates must exhibit characteristics similar to the pathogen. Cryotolerance of healthy and nutritionally-starved cells, ability to attach to lettuce surfaces, ability to survive exposure to 200 ppm free chlorine, and hydrophobicity of non-pathogenic Escherichia coli strains were compared with E. coli O157:H7. Of those evaluated, E. coli ATCC 25922 had traits similar to E. coli O157:H7 and could be a surrogate for E. coli O157:H7 in studies involving attachment and recoverability of this pathogen from chilled produce. Foodborne botulism, a potentially lethal neuroparalytic illness, results when preformed Clostridium
botulinum neurotoxins are ingested. There is little information concerning the stability of preformed toxin on fresh produce. This research determined the stability of toxin type A on whole grape tomatoes, pre-cut lettuce, and pre-sliced cantaloupe. Different combinations of toxin inoculum pH (5.5 or 7.0) and storage temperature (4, 15, or 25 C) were analyzed to determine their relationship to the rate of toxin decay. The toxin was measured using the DIG-ELISA method, which screens for the presence of botulinal toxin type A. For tomatoes, the toxin inoculum at pH 5.5 and storage temperature of 25 C provided the most stability for the toxin. For lettuce, the toxin inoculum at pH 7.0 and storage temperature of 15 C provided the most stability. For cantaloupe, only the temperature of 4 C provided stability to the toxin.
Impacts
The biosecurity training was the first of its kind for participants in the workshops and was very well received. The programs will be offered again in 2006. Undergraduates in the college course indicated that their awareness and understanding of food biosecurity issues increased as a result of taking the course. The E. coli surrogate can be useful in evaluating the risk posed by the possible intentional contamination of fresh produce. The botulinal toxin studies revealed that the inherent produce enzymes, produce maturity, and water loss may contribute to toxin stability on produce surfaces and that toxin stability may vary based on the type of produce, the storage temperature and the pH of the toxin suspension.
Publications
- D'Sa, E. M., and M. A. Harrison. 2005. Effect of pH, NaCl Content, and Temperature on Growth and Survival of Arcobacter spp. J. Food Prot. 68:18-25.
- Phillips, C. A., M. A. Harrison. 2005. Comparison of the Microflora on Organically and Conventionally Grown Spring Mix from a California Processor. J. Food Prot. 68:1143-1146.
- Musgrove, M., D. R. Jones, J. K. Northcutt, N. A. Cox, and M. A. Harrison. 2005. Shell Rinse and Shell Crush Methods for the Recovery of Aerobic Microorganisms and Enterobacteriaceae from Shell Eggs. J. Food Prot. 68:2144-2148.
- Kim, J. K., E. M. D'Sa, M. A. Harrison, J. A. Harrison, and E. L. Andress. 2005 Listeria monocytogenes Survival in Refrigerator Dill Pickles. J. Food Prot. 68:2356-2361.
- Musgrove, M. T., D. R. Jones, J. K. Northcutt, M. A. Harrison, and N. A. Cox. 2005. Impact of Commercial Processing on the Microbiology of Shell Eggs. J. Food Prot. 68:2367-2375.
- Blackman, I. C., Y. W. Park, M. A. Harrison. 2005. Effects of Oxidative Compounds on Thermotolerance in Escherichia coli O157:H7 Strains EO139 and 380-94 J. Food Prot. 68:2443-2446.
- Musgrove, M. T., D. R. Jones, J. K. Northcutt, M. A. Harrison, N. A. Cox, K. D. Ingram, and A. J. Hinton. 2005. Recovery of Salmonella from commercial shell eggs by shell rinse and shell crush methodologies. Poultry Sci. 84:1955-1958.
- Son, Insook. 2005. Prevalence of Arcobacter and Campylobacter on broiler carcasses during processing. Ph.D. Dissertation, University of Georgia. 120 pgs.
- Broeker, Robin Gwen Salinsky. 2005. The stability of Clostridium botulinum toxin type A on fresh and fresh-cut produce. M.S. Thesis, University of Georgia. 74 pgs.
- Chambliss, Lashawnda Sherre. 2005. Thermal injury and recovery of Salmonella Enteritidis in ground chicken with temperature, pH, and sodium chloride as controlling factors. M.S. Thesis, University of Georgia. 51 pgs.
- Akins, E. Deann. 2005. Effect of washing practices on the microflora on Georgia-grown cantaloupes. M.S. Thesis, University of Georgia. 82 pgs.
- Morales, Cesar Augusto. 2005. Evolutionary trends in reproductive tract adapted Salmonella Enterica as characterized by DNA microarray, ribotyping, sequencing, and phenotype microarrayTM. M.S. Thesis, University of Georgia. 92 pgs.
- Garland, Jennifer. 2005. The natural transmission of Salmonella Typhimurium in poultry with and without antimicrobial selective pressure. M.S. Thesis, University of Georgia. 72 pgs.
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Progress 01/01/04 to 12/31/04
Outputs
This project involves extension, research and teaching efforts directed at the bioterrorism risks faced by the fresh and fresh-cut produce industries. Fresh produce is potentially vulnerable to tampering because it is usually eaten raw or in a minimally processed state. It is grown, harvested and packed literally in the open and there is typically no kill step to destroy microbial pathogens prior to consumption. In a collaborative effort with researchers from Georgia, South Carolina and Florida, the current status of security at numerous fresh produce facilities in these states was assessed. Security audit forms were used to survey growers, packers, and fresh-cut processing operations. A total of 25 farms, 25 packinghouses and 7 fresh-cut produce processing operations were surveyed. Practically all of the fresh-cut processors have a written security plan, conduct security training for their employees and have restricted access to their facilities. However, only about
half of the farm and/or packinghouse operations provide employee security training, and only one farm and one packinghouse surveyed have written security plans. About half (52%) of the packinghouses surveyed have perimeter fencing and only half have locks on the cooler doors. Documentation of any sort of security practice is lacking among both growers and packers. Survey data collected to date indicates that while fresh-cut processing facilities are dealing with current security challenges, farm and packing operations in the tri-state region are lagging behind. More training programs and assistance to increase awareness and to facilitate incorporation of feasible, preventative measures are needed by segments of the industry. Lab research focused on two areas. First, potential attachment and internalization of Escherichia coli O157:H7 to fresh produce was investigated using scanning electron microscopy. Pieces (approx. 0.5 x 0.5 cm) of baby carrots and lettuce were inoculated by
submerging them into a suspension of E. coli O157: H7 (8.3 log cfu/ml) for 4 h at ambient (20 C) and refrigeration temperature (4 C). The results indicated that E. coli O157:H7 cells could attach to both carrots and lettuce with greater numbers attached at ambient rather than at refrigeration temperature. E. coli O157:H7 attached to produce surfaces at different angles which may affect intensity of attachment. E. coli O157:H7 could internalize through stomata in lettuce. Due to processing, stomata were missing on the baby carrots. However, visible mechanical damage from processing was observed on the surface of baby carrots and played a role in bacterial internalization. Internalization may result in an underestimation of bacterial contamination and reduce sanitizing efficacy due to limited contact with sanitizing agents. The second research effort focused on the fate of Clostridium botulinum toxin on produce and was initiated in 2004. This portion of the project will be completed by
mid-2005.
Impacts
In auditing produce production, packing and processing facilities several areas were noted where the industry has taken some action related to food security. However, it also brought to the attention areas that have not been sufficiently addressed by the industry. Results from the audits will be incorporated into trainings that are scheduled for 2005 and 2006. The trainings will aid the industry in preparing and implementing food security plans to reduce chances of a bioterrorism incidence with their product.
Publications
- No publications reported this period
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Progress 01/01/03 to 12/31/03
Outputs
This project involves extension, research and teaching efforts directed at the bioterrorism risks faced by the fresh and fresh-cut produce industries. To gain insight into current practices and future needs in the industry, a portion of the efforts in 2003 involved on-site auditing of commercial operations to evaluate their readiness programs in the areas of food security and bioterrorism. Audit forms were developed for use in both fresh and fresh-cut produce operations. They were field tested during site visits at facilities in Georgia. Additional modifications were made and they were distributed to co-investigators in Florida and South Carolina for use during the summer and fall produce seasons in those locations. Initial findings indicate that there was some degree of awareness by commercial operators related to biosecurity and bioterrorism, but the level of emphasis placed on the topic varied. In some cases, operations might indirectly address biosecurity through
existing programs, although they may not be aware of the connection. Additional audits are planned for 2004, which will increase the database. A pilot-scale hydrocooler typical of those used in the produce industry was put in place in our contained food processing lab for research projects to determine the fate of foodborne pathogens in hydrocoolers. Research on the fate of Clostridium botulinum toxin on produce was scheduled to start at the end of 2003, but was delayed due to lab construction problems. The lab should be on-line early in 2004.
Impacts
The development and refinement of a food security audit form should aid personnel extension and the private sector in evaluating the readiness of commercial operations in the area of food security. The form developed has been shown at this point to be comprehensive, yet relatively easy to use. The information gained through the audits will be incorporated into planned training workshops as part of this project.
Publications
- No publications reported this period
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Progress 01/01/02 to 12/31/02
Outputs
This is a new project (started in October 2002). The project advisory team has met and initiated the development of auditing forms to be used during site visits to evaluate food security issues.
Impacts
The primary outreach impact will involve the development of an auditing tool to be used in food security evaluation programs in fresh and fresh-cut produce industries. The team will evaluate the tool by visiting a number of fresh and fresh-cut produce operations in Georgia, South Carolina, and Florida. Modifications to make the audit tool more effective will be made as needed and the finished tool will be made available to the industry. The teaching and research portions of the project will begin during 2003.
Publications
- No publications reported this period
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