Progress 08/15/06 to 08/14/08
Outputs
OUTPUTS: The Iowa State University component of the Food Safety Consortium funded five research projects and two diversity graduate assistantships in 2007-2008. The primary basis for research under this research program has been the enhancement of the safety of pork and pork products. Since the Food Safety Consortium was not funded by special grants during this time period, the funding to continue the program was made available from HATCH funds and other administrative funds within Iowa State University. Diversity Graduate Assistantships: Recognizing the need to enhance diversity in the field of food safety, the Iowa State University portion of the Food Safety Consortium funded two diversity assistantships in 2007 - 2008. The Food Safety Consortium funded two research project relating to preharvest interventions. The first evaluated the immune response of swine to salmonellae, to determine if there are opportunities to prevent contamination of the live animal. They have identified a large number of genes that are differentially expressed in whole blood at 48 hours post salmonella infection between pigs that persistently shed bacteria up to 21 days post infection and those that shed low to non-detectable numbers. Dr. Cornick investigated the potential for Escherichia coli O157:H7 to become endemic in swine. Her research showed that fewer pigs fed diets containing subtherapeutic levels of either tylosin or chlorotetracycline shed E. coli O157:H7 for longer than 2 weeks compared to those fed an antibiotic-free diet. These results suggest that subtherapeutic antibiotics may reduce the persistence of E. coli O157:H7 in swine. Macrolides are an important class of antibiotics used for clinical treatment of campylobacteriosis caused by Campylobater spp. There is a trend that Campylobacter, especially C. coli, is increasingly resistant to macrolides. We also found that the field isolates collected from swine and turkey farms harbored different types of resistance-associated mutations compared with in vitro selected erythromycin-resistant mutants. The Food Safety Consortium funded two post-harvest research projects, one on decontamination and the other on detection methods. Dr. Mendonca's laboratory researched the destruction of Salmonella enterica on pork Skin using a solution of organic acids and surfactants. Dr. Brehm-Stecher's laboratory evaluated flow cytometry as a detection method for foodborne pathogens in pork. Both pathogens were directly detectable at high levels of contamination (106 CFU/g) in cubed pork (Salmonella) and pork franks (Listeria). Unambiguous detection of both pathogens at low levels (102 CFU/g) was also possible after only 8 hours of non-selective preenrichment in either buffered peptone water or universal preenrichment broth. It is imperative that the information developed in the research laboratory be transferred to the general public, in a format which is accessible to them. The Consortium continues to help fund the Food Safety web page. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
1) Contaminated foods or liquid dilutions made from such foods may contain high loads of particulate matter or non-target microflora, both of which could present challenges to the direct detection of target cells. Flow cytometry is a detection technology that allows the rapid analysis of complex microbial populations according to single cell light scatter and fluorescence characteristics. Research funded by the Food Safety Consortium (FSC) has resulted in the refinement of methods to increase detection sensitivities for direct detection of both pathogens in pork meats were as low as 105 CFU/ml. Enumeration with flow cytometery has been shown to be equivalent to tradition methods, but with the results available several hours or days earlier than traditional methods. 2) Campylobacter species including Campylobacter jejuni and Campylobacter coli are the most commonly recognized bacterial causes of foodborne illnesses. Campylobacter is commonly present in farm animals including pigs, chickens, turkeys, cattle and sheep. Recently, C. jejuni and C. coli have become increasingly resistant to antimicrobials, this is considered an emerging public health problem. C. coli isolates from swine and turkeys show much higher resistance rates to macrolides than Campylobacter strains from other animals. Campylobacter resistance to macrolides is still poorly understood. Novel methods are urgently needed for rapid detection of the antimicrobial resistance in Campylobacter to facilitate clinical treatment of campylobacteriosis. Research funded by the FSC has identified previously unrecognized mechanisms for macrolide resistance in Campylobacter. Field isolates collected from farms and the in vitro selected mutants had different types of target mutations. These observations provide new insights into the development of macrolide resistance in Campylobacter. 3) In the past few years there have been several reports linking swine and /or pork products to outbreaks of human disease caused by E. coli O157:H7. Previously research has shown that E. coli O157:H7 can establish and maintain a population in the intestinal tract of some market-weight pigs for at least 2 months. This time period is similar to that which occurs in experimentally inoculated ruminants and suggests that there is not an absolute biological barrier to the colonization of swine by E. coli O157:H7. These results suggest that subtherapeutic levels of antibiotics may reduce the duration of shedding of E. coli O157:H7 by swine. 4) Recognizing the need to enhance diversity in the field of food safety, the Iowa State University portion of the FSC funded two diversity assistantships in 2007-2008. The FSC consumer web-site project continues to receive a significant number of site visits. More than 600,000 visitors have accessed the food safety web site home page or one of its links over the past year. Visitors accessed the site with an average of approximately 10 minutes per visit. While it is difficult to accurately assess consumer education from this information, it is clear that the web site is reaching a broad spectrum of the general public.
Publications
- Patton, B.S., J. S. Dickson, S. M. Lonergan, S. A. Cutler, and C. H. Stahl. 2007 Inhibitory activity of Colicin E1 against Listeria monocytogenes. J. Food Protect. 70:1256-1262.
- Dickson, J.S., S. Kozak, E. Lenchenko, O. Scliarov and B. W. Sheldon. 2007. Comparison of Russian and US Official Methods of Analysis of Poultry for Salmonella. Food Protection Trends. 27:754-756.
- Singh, M. H. Mullins S. Simpson and J.S. Dickson. 2008 Effect of acid adaptation on thermal tolerance of Escherichia coli O157:H7 and Salmonella enterica in meat serum. J. Food Safety; submitted 2 July 2008.
- VuKhac, H and NA Cornick. 2008. Prevalence and genetic profiles of Shiga toxin-producing Escherichia coli strains isolated from buffaloes, cattle and goats in central Viet Nam. Vet. Microbiol. 126:356-363. Cornick, NA and H. VuKhac*. 2008. Indirect transmission of Escherichia coli O157:H7 occurs readily amongst swine, but not amongst sheep. Appl. Environ. Microbiol. 74:2488-2491.
- Niebuhr, S.E., A. Laury, G.R. Acuff and J.S. Dickson. 2008. Evaluation of non-pathogenic surrogate bacteria as process validation indicators for Salmonella enteric for selected antimicrobial treatments, cold storage and fermentation in meat. Journal of Food Protection 71:714-718.
- Johnson, T.J., Kariyawasam, S., Wannemuehler, Y., Mangiamele, P., Johnson, S.J., Doetkott, C., Skyberg, J.A., Lynne, A.M., and Nolan, L.K. 2007. Genome Sequence of Avian Pathogenic Escherichia coli Strain O1:K1:H7 Shares Strong Similarities with Human ExPEC Genomes. J Bacteriol. 189: 3228-3236.
- Johnson, T.J., Wannemuehler, Y.M., Johnson, S.J., Logue, C.M., White, D.G., Doetkott, C., and Nolan, L.K. 2007. Plasmid Replicon Typing of Commensal and Pathogenic Types of Escherichia coli. Appl Environ Microbiol. 73:1976-1983.
- Lynne, A.M., Skyberg, J.A., Logue, C.M., and Nolan, L.K. 2007. Characterization of a Series of Transconjugant Mutants of an Avian Pathogenic Escherichia coli Isolate for Resistance to Serum Complement. Avian Dis. 51:771-776.
- Trampel, D.W., Wannemuehler, Y., and Nolan, L.K. 2007. Characterization of APEC from Peritonitis Lesions in Commercial Laying Hens. Avian Dis. 51:840-4.
- Kariyawasam, S., Scaccianoce, J., and Nolan, L.K. 2007. Common and Specific Virulence-Associated Markers of Avian and Human Extraintestinal Pathogenic Escherichia coli as Determined by Genomic Subtractive Hybridization. BMC Microbiol. 7:81-88.
- Skyberg, J., Johnson, T.J., and Nolan, L.K. 2008. Mutational and Transcriptional Analyses of an Avian Pathogenic Escherichia coli ColV Plasmid. BMC Microbiol. 8:24.
- Johnson, T.J., Wannemuehler, Y.M., and Nolan, L.K. 2008. Evolution of the iss Gene in Escherichia coli. Accepted by Appl Environ Microbiol.
- Johnson, T.J., Wannemuehler, Y.M., Doetkott, C., Logue, C.M., Barnes, H. J., Scaccianoce, J., DebRoy, C., and Nolan, L.K. 2008. Emergence of Class 1 Integrons on Promiscuous Plasmids in Avian Pathogenic Escherichia coli. Under review
- Johnson, T.J., Wannemuehler, Y., Doetkott, C., Johnson, S.J., White, D.G., and Nolan, L.K. 2008. Escherichia coli of Retail Poultry Meat Show More Similarity to ExPEC than Commensals and May Not Originate from Fecal Contamination. Under review
- Johnson, T.J., Wannemuehler, Y., Doetkott, C., Johnson, S.J., and Nolan, L.K. 2008. Identification of Minimal Predictors of Avian Pathogenic Escherichia coli (APEC) Virulence for Use as a Rapid Diagnostic Tool. Under review
- Sindhuja, S., S.K, Khanal, A.L. Pometto III, and J. Van Leeuwen. 2008 Ozone as a selective disinfectant for nonaseptic fungal cultivation on corn-processing wastewater. Biotech. and Bioengineering (in press)
- Isci, A., J. Himmelsbach, A. L. Pometto III, R. Raman, and R. Anex. 2008. Aqueous Ammonia Soaking of Switchgrass followed by Simultaneous Saccharification and Fermentation. Appl. Biochem. Biotech. 144:69-77.
- Shrestha, P., M. Rasmussen, S. K. Khanal, A. L. Pometto III, J (Hans) van Leeuwen. 2008. Saccharification of Corn Fiber by Phanerochaete chrysosporium in Solid-State Fermentation and Subsequent Fermentation of Hydrolysate into Ethanol. J. Ag. Food Chem. (In Press)
- Isci, A., J. N. Himmelsbach, J. Strohl, A. L. Pometto III, D. R. Raman, and R. P. Anex. 2008. Pilot Scale Fermentation of Aqueous Ammonia Soaked Switchgrass, Appl Biochem. Biotech. (In Press)
- Husak, R.L. and J.G. Sebranek. 2008. A survey of commercially available broilers originating from organic, free-range, and conventional production systemsfor cooked meat yields, meat composition and relative value. Poultry Sci. (in press).
- Sindelar, J.J., J.C. Cordray, J.G. Sebranek, D.G. Olson and J.A. Love. 2007. Investigating quality attributes and consumer acceptance of uncured, no nitrate/nitrite-added commercial hams, bacons and frankfurters. J. Food Sci. 72:S551-S559.
- Sindelar, J.J., J.C. Cordray, J.G. Sebranek, J.A. Love and D.U. Ahn. 2007. Effects of varying levels of vegetable juice powder and incubation time on color, residual nitrate and nitrite, pigment, pH and trained sensory attributes of ready-to-eat uncured ham. J. Food Sci. 72: S388-S395.
- Sebranek, J.G., and J.N. Bacus. 2007. Natural and organic cured meat products: regulatory, manufacturing, marketing, quality and safety issues. AMSA White Paper Series, No. 1. American Meat Science Association, Savoy, IL.
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Progress 08/15/06 to 08/14/07
Outputs
The Iowa State University component of the Food Safety Consortium funded four research projects, two equipment grants and two diversity graduate assistantships in 2006-2007. Research scientists representing several academic departments at the University, as well as USDA-ARS and HHS-FDA, were involved. The primary basis for research under this research program has been the enhancement of the safety of pork and pork products. The research projects encompassed many aspects of food safety as it is currently viewed, from the farm to the consumer. Diversity Graduate Assistantships for Underrepresented groups: The two students receiving support were Ph.D. students, one working in the area of risk assessment and the other in animal science. Equipment Grants: In 2006-2007, the Food Safety Consortium provided funding for the purchase of a tri-gas incubator for the cultivation of Campylobacter, and an image analysis system for the evaluation of a variety of applications, from
disk diffusion assays to electrophoresis gels. Research Grants: Drs. Jensen and Hurd addressed the question of how changes at various points in the pork production process affect the predicted number of human salmonellosis cases attributable to pork and the costs of alternative control interventions. These resulting change estimates (quantitative mitigation elasticity) and relative costs will provide meat industry management and food safety policy makers a tool to evaluate and determine priority areas for intervention that are indeed risk-based and cost effective. Drs. Zhang and Wesley evaluated the antimicrobial resistance of Campylobacter found in live pigs. They investigated the antimicrobial resistance profiles of Campylobacter coli isolates cultured from two swine farms at different production stages. Using the standard agar dilution test, each isolate was tested against five different antibiotics. Comparing resistance to the production stage from which the isolates were derived,
no apparent correlation could be seen for ciprofloxacin, doxycycline or erythromycin on either farm. Dr. Harris and Mr. Gaul developed a quantitative PCR method which was reliably able to detect 104 colonies of salmonella from swine holding pens. Samples which contained less than 1,000 cells could not be detected using qPCR. Dr. Sebranek's research has focused on the production of nitrite from natural sources. Preliminary work has focused on processing procedures to assure an appropriate level of nitrite produced under various manufacturing circumstances. Additional work is examining the microbiology of the culture used to convert nitrate to nitrite. The Consortium continues to help fund the Food Safety web page designed and maintained under the direction of Mr. Jason Ellis. The Food Safety Consortium (FSC) consumer web-site project continues to receive a significant number of site visits and be recognized for its work.
Impacts
The primary focus of the work of the Food Safety Consortium continues to be methods development for the isolation, detection and quantification of microbial and chemical hazards and the elimination of those hazards. Because of our research, we now have better methods of isolating and identifying foodborne pathogens, have better interventions in both the live animal and the product, and have conveyed this information to other scientists, regulatory agencies, the industry and to consumers. As part of the research effort, the Consortium continues to train the next generation of scientists who will assure that the United States is prepared to face food safety challenges, either natural or intentional, for decades to come. Our food safety work has prepared us to address food security that may be the result of bioterrorism and/or natural disasters. The Food Safety Consortium is providing the necessary research to achieve these goals. Consortium researchers at Iowa State
University are working to enhance the safety of pork at all levels of the production chain, from the farm to the table. The Consortium was established in 1988. The purpose of the Consortium, as defined by Congress, is fourfold: 1. To develop technology for rapid identification of infectious agents and toxins; 2. To develop a statistical framework necessary to evaluate the potential health risks; 3. To determine the most effective intervention points to control microbiological or chemical hazards; 4. To develop risk-monitoring techniques to detect potential hazards in the distribution chain.
Publications
- Michaelsen, A., J.G. Sebranek and J.S. Dickson. 2006. Effects of Microbial Inhibitors Combined with Modified Atmosphere Packaging on Growth of Listeria monocytogenes and Salmonella enterica Typhimurium and on the Quality Attributes of Injected Pork Chops and Cured, Sliced Ham. Journal of Food Protection J. Food Protect. 69:2671-2680.
- Singh, M., S.M. Simpson, H.R. Mullins and J.S. Dickson. 2006. Thermal tolerance of acid adapted and non-adapted Escherichia coli O157:H7 and Salmonella in ground beef during storage. Foodborne Pathogens & Disease
- Singer, R.S., L. A. Cox, Jr. J. S. Dickson, H. S. Hurd, I. Phillips, and G. Y. Miller. 2007. The Relationship between Food Animal Health and Human Foodborne Illness. Preventive Veterinary Medicine 79:186-203.
- Hurd, H.S., J. Brudvig, J. Dickson, J. Mirceta, M. Polovinski, N. Matthews, and R Griffith. 2007. Swine health impacts on carcass contamination and human foodborne risk. Public Health Reports.
- Sebranek, J.G., and J.N. Bacus. 2007. Cured meat products without direct addition of nitrate or nitrite; what are the issues? Meat Sci. 77:136-147.
- Laury, A. M., and J.G. Sebranek. 2007. Use of carbon monoxide combined with carbon dioxide for modified atmosphere packaging of pre-rigor and post-rigor fresh pork sausage. J. Food Protect. 70:937-942.
- Cornick, NA, AF Helgerson, V Mai, JM Ritchie, DWK Acheson. 2006. In vivo transduction of stx-encoding phage in ruminants. Appl. Environ. Microbiol. 72:5086-5088.
- Helgerson, AF, V Sharma, AM Dow, R Schroeder, K Post and NA Cornick. 2006. Edema disease caused by a clone of Escherichia coli O147:H17. J. Clin. Microbiol. 44:3074-3077.
- Cornick, NA, AF Helgerson and V Sharma. 2007. Stx-encoding phage does not facilitate colonization of E. coli O157:H7 in sheep. Appl. Environ. Microbiol. 73:344 346.
- Rababah, T., N. S. Hettiarachchy, R. Horax, M. J. Cho, B. Davis, and J. Dickson. 2006. Thiobarbituric Acid Reactive Substances and Volatile Compounds in Chicken Breast Meat Infused with Plant Extracts and Subjected to Electron Beam Irradiation. Poultry Science 85:1107-1113.
- Jun Lin, Meiguan Yan, Orhan Sahin, Sonia Pereira, Yun-Juan Chang, and Qijing Zhang. 2007. Effect of macrolide usage on the emergence of erythromycin-resistant Campylobacter in chickens. Antimicrob. Agents Chemother. 51:1678-1686.
- Sneed, J, Strohbehn, C.H., & Gilmore, S. 2007. Impact of mentoring on food safety practices and HACCP implementation in Iowa assisted-living facilities. Topics in Clinical Nutrition, 22(2).
- Ravichandran, S., Gilmore, S., Strohbehn, C.H. 2006. Organizational citizenship behavior research in hospitality: Current status and future research directions. Journal of Human Resources in Hospitality and Tourism, 7(2).
- Fengxia Dong and Helen H. Jensen Challenges for Chinas Agricultural Exports: Compliance with Sanitary and Phytosanitary Measures in B. Babcock, H. Jensen and R. Nayga (eds.), Export-Led Changes to Domestic Food Quality Assurance. Choices. 22 (1, March) 2007.
- J. Caswell and H.H. Jensen (eds). Special Issue of Agribusiness: An International Journal on Economic Measures of Interventions in Setting Priorities in Food Safety. 23(2, Spring) 2007.
- Sindelar, J.J., J.C. Cordray, J.G. Sebranek, J.A. Love and D.U. Ahn. 2007. Effects of vegetable juice powder concentration and storage time on some chemical and sensory quality attributes of uncured emulsified cooked sausages. J. Food Sci. 72:S324-S332.
- Gaul, Stephen B., Stephanie Wedel, Matthew M. Erdman, D.L. Harris, Isabel Turney Harris, Kathleen E. Ferris, and Lorraine Hoffman. 2007. Use of pulsed-field gel electrophoresis of conserved XbaI fragments for identification of swine Salmonella serotypes. Journal of Clinical Microbiology, 45:472-476
- Payot, S., J-M Bolla, D. Corcoran, S. Fanning, F. Megraud , and Q. Zhang . 2006. Mechanisms of fluoroquinolone and macrolide resistance in Campylobacter spp. Microbes Infect. 8:1967-1971.
- Zhang, Q., O. Sahin, P. F. McDermott, and S. Payot. 2006. Fitness of antimicrobial resistant Campylobacter and Salmonella. Microbes Infect. 8:1972-1978.
- Yan, M., O, Sahin, J. Lin, and Q. Zhang. 2006. Role of the CmeABC efflux pump in the emergence of fluoroquinolone-resistant Campylobacter under selection pressure. J. Antimicrobial. Chemother. 58:1154-1159.
- Luangtongkum, T., T. Y. Morishita, A. B. Al-Tayeb, A. J. Ison, and Q. Zhang. 2007. Comparison of antimicrobial susceptibility testing of Campylobacter spp. by the agar dilution and the agar disk diffusion methods. J. Clin. Microbiol. 49:590-594.
- Su, C. C., F. Shi, R. Gu, M. Li, G. McDermott, E. W. Yu, and Q. Zhang. 2007. Preliminary structural studies of the transcriptional regulator CmeR from Campylobacter jejuni. Acta Crystallograph. Sect. F. Struct. Biol. Cryst. Commun. 63:34-36.
- Shouxiong Huang, Orhan Sahin, and Qijing Zhang. 2007. Infection induced antibodies against the major outer membrane protein of Campylobacter jejuni mainly recognize conformational epitopes. FEMS Microbiol. Lett. 272:137-143.
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