Escherichia coli and Their Significance by ewghwehws


									Emerging Technologies for the Control
of Foodborne Pathogens and the USDA-
     Pathogen Modeling Program
        Vijay K. Juneja, DVM., MS., Ph.D.
          Microbial Food Safety Research Unit
           Eastern Regional Research Center
                     ARS - USDA
                600 East Mermaid Lane
            Wyndmoor, Pennsylvania 19038
                 Phone: 215-233-6500
                  Fax: 215-233-6697
        Agricultural Research Service
      National Program 108 (Food Safety)
Mission Statement:
 The mission of Food Safety Program is to provide the
 means to ensure that the food supply is safe for
 consumers and that food and feed meet foreign and
 domestic regulatory requirements. To decrease the
 hazards of both introduced and naturally occurring
 toxicants in foods and feed, including pathogenic
 bacteria, viruses and parasites, chemical contaminants,
 mycotoxins produced by fungi growing on plants, and
 naturally occurring toxins produced by plants.
        Agricultural Research Service
      Research and Technology Transfer
The USDA Agricultural Research Service Food Safety
Program addresses prevention and control of food
pathogens, the production, harvesting, processing,
transportation, handling, and storage of food (the farm to
table continuum), and the prevention of toxic chemical
hazards in food through research programs that benefit
producers, processors, and the public.
           Agricultural Research Service
         National Program 108 (Food Safety)
Vision Statement:
  Safe food available to every American at home, when eating out,
  or in institutional settings, and the knowledge needed to keep that
  food safe until consumption.
• The research components of this program include:
       Microbial Pathogens
       Chemical Residues
       Toxic Plants
The Agricultural Research Service (ARS) is the Chief
              Scientific Agency of the
          U.S. Department of Agriculture

• 100 Locations, in All
  50 States +
  International Sites
• 2200 Ph.D. Scientists
• 8000 Employees
• >$1 Billion Budget
• $105 Million for Food
  Safety, 77 Projects +
                     ARS National Programs
Animal Production    Nutrition/Safety     Natural Resources           Crop Production
                     Human Nutrition      Water Quality &           Plant, Microbial & Insect
Animal Production
                                          Management                Germplasm Conservation
Animal Health        Food Safety                                    & Development
                                          Soil Resource
Arthropod Pests of                        Management                Plant Biological &
Animals and Humans   New Uses, Quality                              Molecular Processes
                     & Marketability of   Air Quality
Animal Well-Being    Plant & Animal                                 Plant Diseases
                                          Global Change
and Stress Control   Products                                       Crop Protection &
Systems                                   Rangeland, Pasture &
                                                                    Crop Production
                                          Manure & Byproduct
                                          Utilization               Bioenergy & Energy
                                          Integrated Agricultural
                                          Systems                   Methyl Bromide
Agricultural Research Service:   $102M
       Pre-harvest $60M
       Post-arvest    $42M

Eastern Regional Research Center: $18M
   ~18% of total food safety budget
   ~43% of post-harvest budget
  Four regional research centers, provide the major portion of ARS's
  capability for research and development of technology to increase the use of
  agricultural products and thereby enhance the economic viability and
  competitiveness of U.S. agriculture.

        NCAUR (NRRC) – Peoria, Illinois                                SRRC – New Orleans, LA

             ERRC – Wyndmoor, Pennsylvania                             WRRC – Albany, California
Worksites:                               $31.5 mil Budget
- University of Maryland Eastern Shore   300 Employees
- Delaware State University              90 PhD Scientists/Engineers
                                         17 Research Associates
ERRC Stakeholder
Although the United States maintains one of the safest
            food supplies in the world…
Per year in the USA
• 5,000 deaths (0.002%)
• 325,000 hospitalizations (0.1%)
• 76 million cases (27.5%)
• $5 to $8.4 billion in costs            Total Cases per year in USA

                                    Campylobacter            1,963,000 (14.2%)
                                    Salmonella               1,342,000 (9.7%)
                                    E. coli 0157:H7            92,500 (0.5%)
                                    Listeria monocytogenes       2,000 (-)
       Mead et al., 1999
                 Pathogens of concern
                  (Meat and Poultry)

• The most common foodborne bacterial pathogens
  associated with meat and poultry are: Campylobacter
  jejuni (poultry), Escherichia coli 0157:H7 (ground beef
  and pork), Listeria monocytogenes (beef, pork, poultry,
  and sea food), Salmonella species (beef, pork, poultry,
  and sea food), Staphylococcus aureus (beef, pork, and
  poultry), and Yersinia enterocolitica. (meat and seafood).
            Potential Emerging Pathogens

• Hepatitis E virus
• Chronic wasting disease (TSE that
  affects deer and elk)
• Multiple antibiotic-resistant
• Non jejuni/coli Campylobacter spp.
• Non O157 Shiga toxin-producing E.
  coli (enterohemorrhagic E. coli,
  EHEC), and other diarrheagenic E.
  coli groups
• Enterobacter sakazakii
Food Safety – The Big Picture!
                       - Find, Characterize, & Kill
                  Thermal                                Non-Thermal (New, Developing)
      Varying Cooking Temperatures/Times,                   Physical, Chemical, Biological,
           HTST/UHT Pasteurization                          and Electromagnetic Processes

                         Slaughter        Fabricate       Process
                                  Centers of Excellence in
                             Process Validation (BSL-2 & BSL-3)

                               People – 40 to 50: Budget - $6.5M
Raw Materials                    Locations – PA, DE, MD, & GA           Finished Products
                                   Publications - >125/year

    Recovery/Characterization                                      Modeling
• Biosensors (Rapid Detection Technologies)    • Predictive Microbiology (PMIP) (PMP,
• Nucleic Acid (PCR, PFGE)
                                               • Center of Excellence in Microbial Modeling and
• Genomics & Proteomics (Omics)                  Informatics (CEMMI)
              Food Preservation

• Aseptic handling to prevent or minimize entry of
  microorganisms into food
• Physically removing microorganisms in food
• Killing microbial cells and spores present in foods
• Preventing or reducing the growth of microorganisms
  and germination of spores present in foods
 Major Existing Technologies for Food Preservation

• Techniques that slow or          • Techniques that inactivate
  prevent the growth of              microorganisms
  microorganisms                      – Heating
   – Reduction in temperature            Pasteurization
   – Reduction in water activity         Sterilization
   – Reduction in pH
   – Removal of oxygen             • Techniques that restrict
   – Modified atmosphere
     packaging                       access of microorganisms
   – Addition of preservatives        – Packaging
                                      – Aseptic processing
New and Emerging Technologies for
       Food Preservation
 • Natural additives
    – Animal-derived antimicrobials
    – Plant-derived antimicrobials
    – Microbial products
 • Physical processes
    –   Irradiation
    –   High hydrostatic pressure
    –   Electrical methods
    –   Ultrasound
Predictive Microbiology
 Thermal Inactivation of Foodborne

• The models:
  –   Develop HACCP Plans
  –   Validate HACCP Plans, or
  –   The effects of process deviations
  –   Determine the relative severity of a problem
  –   Finally, plan for corrective actions
 “PMIP”                                                      10,000,000
                                                                                   Fate of Pathogens in Food
 Predictive Microbiology Information Portal                                       100,000
                                                                                   10,000                    Survival

                                                               Bacterial levels

 Modeling Viability and Transfer of
 Pathogens in Raw, Fermented, and
 Ready-to-Eat Foods

Examples of Parameters that Affect The
Fate of Pathogens in Foods                                                                    Pathogen Modeling Program:
                                                                                              •Used by 30% of Food Industry
 Intrinsic:             Extrinsic:             ComBase:
                                                                                              for HACCP validation
 •pH                    •Storage temperature   •42,000 Records of growth,
 •Aw                    •RH of environment                                                    •5000 Online users in 35
                                               survival, and inactivation of
 •Oxidation potential   •Modified Atmosphere                                                  countries annually
                                                                                              •Portuguese, Chinese, Spanish
Center of Excellence in Microbial Modeling
              & Informatics
   Predictive Microbiology Information Portal
       Regulations          Models   Useful Links

•Final Rule on Listeria
monocytogenes in RTE Meat
and Poultry Products
•“Zero Tolerance” Policy
  Pathogen Modeling Program (PMP) 7.0

The PMP is a repository of models that estimate the behavior of
bacterial pathogens in specific environments.

Through a user interface, information is provided about the
effects of environmental factors on:

      - growth
      - inactivation (thermal and non-thermal)
      - toxin production
CRIS 57                Predictive Models For Foodborne                              CRIS 57
                           Pathogens (Applications)
      -- Web-based database for food microbiology data consisting of thousands of
      microbial growth and survival models

      -- Major international initiative to coordinate collection and dissemination of food
      microbiology data – ERRC and Institute of Food Research


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