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Fresh Produce and Human Pathogenicity Fresh Produce _ Human.pdf by shenreng9qgrg132

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									                     Fresh Produce and Human Pathogenicity
                           Prof. Keith Warriner, University of Guelph
                                  A Webber Training Teleclass

                                                                                   Objectives
        Fresh Produce &
      Human Pathogenicity                            • Food safety outbreaks linked to fresh
                                                       produce
              Prof. Keith Warriner                   • Human pathogens linked to fresh produce
                  University of Guelph
                 kwarrine@uoguelph.ca                • Sources of contamination
                                                     • Interaction of human pathogens with
                                                       growing plants
                                                     • Current and future initiatives
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                paul@webbertraining.com

                www.webbertraining.com




                                                                           Fresh Produce Industry
Fresh Produce Market                               United States
                                                                                                Production Regions
                                                                Million $
        - - at
• Ready to e Salads Market Growing at
                                                   Leafy Greens 2140
  10% per Year
                                                   Tomatoes     1637
• 6 Million Bags of fresh cut produce sold                                                                            25%

  daily                                            Potato       1247
                                                                                                                      1%
• Current Market Value >US$70bn                    Onions        905                            74%


• Greater Diversity of Produce Available (All
  Year Round)
                                                                                               California   Arizona    Other
• Centralized Production




                                                          Outbreaks Associated with
                    Ontario
                                                              Salad Vegetables
                                                                           12
                       Million $                                           10
                                                          Outbreaks/year




    Lettuce             9.91                                                8

    Spinach             28.00                                               6

    Sprouts              4.0                                                4

                                                                            2
    Tomatoes           245.45
                                                                            0
                                                                                1973-79   1980-89             1990-97


                                                        Source: Centre for Disease Control & Prevention, USA

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                    Fresh Produce and Human Pathogenicity
                         Prof. Keith Warriner, University of Guelph
                                A Webber Training Teleclass
                                                        2006 Annus horribilis (North America)

                                                  •   Sprouts (Ontario) Feb Suspected Salmonella
                                                  •   Sprouts (Australia) Feb Salmonella 100 cases
                                                  •   Lettuce June E. coli O121:H19 4 cases
                                                  •   Sprouts Aug Suspected Salmonella
                                                  •   Spinach Sept E. coli O157:H7 202 cases
                                                  •   Carrot Juice Sept Cl. botulinum 6 cases
                                                  •   Lettuce (Ontario) Oct E. coli O157:H7 30 cases
                                                  •   Lettuce Oct 8, 500 carton recall due to
                                                      suspected E. coli




             -
• Tomatoes Oct Nov Salmonella 400 cases

            -
• Lettuce Nov    e
                Dc E. coli O157:H7 132 cases

• Strawberries Nov Suspected L. monocytogenes


• Cantaloupes Dec Suspected Salmonella

• Spinach (Ontario) Dec Suspected Salmonella




                                                       Why the increase in Foodborne
                                                          illness cases & Recalls
                                                   • Larger volume of product
                                                   • Increased awareness of food safety
                                                   • Better detection and investigation
                                                   • Lack of effective initiatives
                                                   FDA: 2 letters to California growers
                                                   Lack of urgency
                                                   Lack of understanding of human
                                                     Pathogen:Produce interactions



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                        Fresh Produce and Human Pathogenicity
                             Prof. Keith Warriner, University of Guelph
                                    A Webber Training Teleclass
         Human Pathogens Linked to
                 Produce                               Listeria monocytogenes
    Escherichia coli O157:H7                           Cabbage
    Lettuce, Spinach, Sprouts
                                                       Cyclospora
    Salmonella                                         Basil, Raspberries
    Tomatoes, Lettuce, Cantaloupe, Sprouts,
      Mangoes, Almonds
                                                       Hepatitis A
                                                       Green onions, soft fruit
    Shigella sonnei
    Parsley, Lettuce, Green onions




     Why Pathogens Linked to Certain
               Produce?
    • Unknown
                                                          Human Pathogens Linked to
    • Pathogens within the environment?                        Fresh Produce
    • Pathogens adapted to produce?




         Escherichia coli O157:H7                                       Symptoms

•   Gram negative rod.
•   Facultative anaerobic
•          - 0˚C
    Temp 10 5 (opt 37˚C).                                                         Low infective dose
•   Min aW 0.93                                                                    - 00
                                                                                  10 1 cells

• Remain viable at low pH
  especially at low temps.

                                                                                  Heamolytic Uremic
                                                                                  Syndrome


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                    Fresh Produce and Human Pathogenicity
                          Prof. Keith Warriner, University of Guelph
                                 A Webber Training Teleclass
                                                                Sources of
                                                          Escherichia coli O157:H7
                                                    • Manure from cattle and other ruminants

                                                    • Farm effluent

                                                    • Person-to-Person contact

                                                    • Wild animals




                  Shigella
Shigella dysenteriae                                • Similar symptoms to EHEC
Shigella sonnei                                     • Very low dose required (10 – 100 cells)

Fecal-Oral route or via contaminated foods          • Typically pathogen transferred directly
                                                      from fecal material or food handlers
Very low tolerance to environmental stress
 and typically only recovered in GI tract or
 fresh sewage




                Salmonella                               Taxonomy of Salmonella
• Gram negative non  -                              • Salmonella group composed of very
  sporulating rod                                     closely related serovars.
• Facultative anaerobic
• Temp for growth 5-
  46˚C (opt 35 3˚C).
              - 7                                   • Only two species Salmonella enteritica
• Min pH 4.5
                                                      and Salmonella bongori
• Min aW 0.97
                                                    • Serotyping (antibody reaction) used to
                                                      differentiate types.



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                    Fresh Produce and Human Pathogenicity
                       Prof. Keith Warriner, University of Guelph
                              A Webber Training Teleclass
        Most Frequent Serotypes
                                                    Salmonella Typhimurium DT 104
         Associated with Food

• S. Typhimurium                                       • Why is DT 104 of concern ?
                                                         – Multiple antibiotic resistance
                                                            • Ampicillin
• S. Enteritidis
                                                            • Chloramphenicol
                                                            • Streptomycin
• S. Dublin                                                 • Sulfonamides
                                                            • Tetracycline




                   Symptoms
• Typhoid or paratyphoid fever from S. typhi     • Infective dose 102 – 106
  and S. paratythi
Salmonellosis
                                                 • Invasion of small intestine and colon by
• Headache                                         entering absorptive mucosal cells and
• Fever                                            mucosa associated macrophages.
• Diarrhea
• Nausea
                                                 • Grow inside fixed macrophages of liver
• Vomiting                                         and spleen.




      Secondary Complications
                                                       Sources of Salmonella
• Arthritis                                      • Poultry and pig manure

• Ms Reynard
                                                 • Sewage

• Salmonella from
  Chinese meal                                   • Wild animals

• $2.5m Payout                                   • Insects



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                   Fresh Produce and Human Pathogenicity
                         Prof. Keith Warriner, University of Guelph
                                A Webber Training Teleclass

      Listeria monocytogenes                       •    Psychrotrophic
                                                   •    Growth range 1 - 44˚C
• Gram positive non-
  spore forming rod
                                                   •    Opt temp 35-37˚C
• Facultative anaerobe                             •    pH 5.0 – 9.6
• Catalase positive                                    (opt 6 – 8) Survives at pH 4
• Oxidase negative
• heamolytic                                       • Min aW 0.93

                                                   • Can survive in 25-30% NaCl solutions




     Listeria Infection Process




                   Illness
Healthy individuals: Mild flu                      • Infective dose for high risk groups 109
                                                   • 30% mortality rate
High risk groups (young, pregnant, old,
  immuno-compromised:
                                                   • Incubation period 1-4 weeks
Stillbirth or abortion
Meningitis
Septicemia                                         • Illness can last 1-90 days
Pneumonia



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                           Fresh Produce and Human Pathogenicity
                             Prof. Keith Warriner, University of Guelph
                                    A Webber Training Teleclass

    Sources of L. monocytogenes                                          Human Parasites
  • Decaying plant material                                  • Protozoan

  • Manure                                                   • Viruses

  • Drains                                                    The majority require human host to
                                                              replicate.
  • Endemic within processing facilities                      Infected handlers or human sewage




  Route of infection-Faecal oral                                              Cyclospora
                            Ingested orally by new host,    • Increasing number of
       Ingestion                 from food or water           cases in Ontario
                                         or
                              transferred to food via ill   • Mexican basil
Replication in intestine           worker (carrier)
                                                            • Fecal contamination
                            Infectious dose is normally
      excretion                           - 00
                                     low 10 1                       - - erson
                                                            • Person to P
                                                              less significant




                                                              Viral Hepatitis: associated virus
                                                                      Hepatitis A and E


                                                            Most commonly
                                                            associated with foods
                                                            •Jaundice
                                                            •Liver damage
                                                            •Abdominal discomfort
                                                            •Fever



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                    Fresh Produce and Human Pathogenicity
                         Prof. Keith Warriner, University of Guelph
                                A Webber Training Teleclass
                                                                              Infected persons can pass Hepatitis A
 Viral Hepatitis: associated virus                                            without showing symptoms
            Hepatitis A
                                                                        Infection
• Hepatitis A is usually a mild illness                                         Incubation
                                                                                Period          Symptoms Resolution
  characterized by sudden onset of fever,




                                                       Hepatitis A in Stool
  malaise, nausea,anorexia, and abdominal
  discomfort, followed in several days by jaundice.



• Hepatitis A represents about 1/3 of all cases of
  viral hepatitis.
                                                                               0          14               28

                                                                                             Time (Days)




• Transmitted via person-to person contact,
  water and through food (fruit a specific                                     Sources of Hepatitis A
  problem).
                                                      • Infected food handlers
• 150, 000 cases a year in United States.
                                                      • Water contaminated with human sewage
• In developing countries incidence in
  indigenous population is low, due to
  “childhood vaccination”, Vaccine is
  recommended for travellers.




                                                                               • Farm
                                                                               Irrigation water
    Sources of Contamination                                                   Run-off from effluent lagoons
                                                                               Manure
                                                                               Workers
                                                                               Wild animals
                                                                               Insects



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                    Fresh Produce and Human Pathogenicity
                      Prof. Keith Warriner, University of Guelph
                             A Webber Training Teleclass

 Survival of Pathogens in Manure
• E. coli O157:H7    >100 days                                                                   • Processing Facility
                                                                                                 Water
• Salmonella         >200 days                                                                   Food handlers
                                                                                                 Processing environment




                                                                                                   Soure of Produce Related Outbreaks

                                                  % o f Pro d u ce related O u tb reaks   120

      • User interface                                                                    100

      Cross-contamination (cutting boards)                                                80
      Handling                                                                            60
      Temperature abuse
                                                                                          40

                                                                                          20

                                                                                           0
                                                                                                1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001


                                                                       Food Service/Consumer                                    Farm + Processor




                                                                                                 Spinach E. coli O157
                                                • Salinas Valley
                                                • 26 States and within Canada
      Interaction of Human                      • 199 confirmed cases
     Pathogens with Produce                     • 3 Deaths
                                                >$100m in loss sales and production


                                                • Previous outbreak in California 2003
                                                16 cases (2 deaths)



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                        Fresh Produce and Human Pathogenicity
                          Prof. Keith Warriner, University of Guelph
                                 A Webber Training Teleclass

            Rapid Response                               PFGE Banding Pattern
• Traceability



• Molecular typing

Rapid connection between cases and trace
 back




            Salinas Valley CA




     What they think happened                             Pre-Washed Spinach
E. coli O157:H7 genotype
• Infected persons

• Product
                            1 mile

• Processing facility

• Cattle ranch near
  spinach field.
                                                     How Effective is Washing?
                                                     Does Triple Wash Mean Anything?


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                                 Fresh Produce and Human Pathogenicity
                                        Prof. Keith Warriner, University of Guelph
                                               A Webber Training Teleclass

    Commercial Post-Harvest Washing                                    Commercial Post-Harvest Washing
                   Spinach External Counts                                            Spinach Internal Counts

            8                                                                  6
log cfu/g




            6




                                                                   log cfu/g
                                                                               4
            4
            2                                                                  2
            0                                                                  0
                Pre-harvest             Pre-wash       Post Wash                   Pre-harvest       Pre-wash      Post Wash

                      TVC        Coliforms     Pseudomonas                               TVC     Coliforms   Pseudomonas




                Post-Harvest Washing                                                Stomata        Biofilm

   • Cross-contamination as opposed to
     decontamination.

   • Hypochlorite rapidly sequestered

   • Internalized populations protected

   • Biofilms




                              Stomata                                          Location of Bacteria Surviving Biocidal
                                                   Waxy Cuticle
                                                                                             Washing

                                                                        •BacLight Nucleic Acid Staining




                   Upper Side of washed Spinach Leaf




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                            Fresh Produce and Human Pathogenicity
                               Prof. Keith Warriner, University of Guelph
                                      A Webber Training Teleclass
          Human Pathogens as                              Interaction of E. coli with Growing
             Endophytes                                             Spinach Plants
• Could human pathogens become
  integrated into plant endophytic                       Potential routes:
  microflora?                                            • Seed

• Protected against UV and desiccation in
  the field
                                                         • Growth Matrix (soil/hydroponic solution)

• Protected against post-harvest biocidal
  washing




          Bioluminescent E. coli                                E. coli on Spinach Roots




                                             Dark
          Light
                             Day 15




                                                        Spinach       TAC                 E. coli O157
                      In Situ Gus Assay                 Plants       Log cfu/g             Log cfu/g

                                                                  Surface    Internal   Surface   Internal
            Seedling from E. coli Inoculated Seed



                                                        Day 9     5.97       2.31       5.91      2.46
                            Stem
   Root
                                             Leaf
                                                        Day 49    5.49       2.36       5.51      ND

                  Control


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                                 Fresh Produce and Human Pathogenicity
                                       Prof. Keith Warriner, University of Guelph
                                              A Webber Training Teleclass
   Conclusions from Inoculated
                                                                                                                  Inoculated Soil
             Seeds
• Internalization of E. coli during early stages of                                              10
  germination                                                                                                                         TVC
                                                                                                 8




                                                                                 log cfu/g
                                                                                                 6
• E. coli established on/within roots and surface of                                                                                 E. coli
  leaves in mature plants                                                                        4
                                                                                                 2
                                                                                                 0
                                                                                                      0       5   10 15 20 25 30 35 40
                                                                                                              Time after planting (Days)




Counts on Spinach
   Days after                       TVC
                                             Log cfu/g
                                                           E. coli
                                                                                Conclusions from Contaminated
   Planting
                           Wash           Extract   Wash             Extract                  Soil
                           6.3              6.0     3.4                2.2
    12                                                                         • E. coli proliferates in soil over the duration
    14                     5.4               5.7    2.2                ND        of plant cultivation.
                           6.6               3.9    6.0                ND
    16
    20                     5.9               4.7    3.2                ND      • E. coli becomes established internally/
                           6.4               5.2    4.7                ND
                                                                                 externally on roots. Surface of leaves.
    23
                           6.8               5.1    4.7               ND
    25                                                                         • Low level of internalization in mature
                           6.4               4.3    5.2               2.1*
    32                                                                           plants
                           7.5               3.9    6.3               2.9*
    35
   1 plant positive from a batch of three tested      ND: < 1 log cfu/g




                                                                                      E. coli (103 cfu/ml) Inoculated into Nutrient
                Spinach Cultivation                                                                     Solution

• Nutrient Film
  Technique (NFT)                                                                            4
  Hydroponic System
                                                                                             3
                                                                               log cfu/m l




     -
• Soil free cultivation
                                                                                             2

• Safer?                                                                                     1

                                                                                             0
                                                                                                 0        2     4     6     8 10 12 14         16    TVC
                                                                                                              Time after inoculation (days)          E. coli

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                                 Fresh Produce and Human Pathogenicity
                                        Prof. Keith Warriner, University of Guelph
                                               A Webber Training Teleclass
                   Bacterial Counts From
                                                                                          Vacuum Cooling
                      Spinach Plants
               8
                          Root                       Leaves
               7
               6
   log cfu/g




               5
               4
               3
               2
               1                                                  ND
               0    TVC       E. coli               TVC        E. coli
                                          1
                      Wash              Surface Sterilised

                                         ND: <1 log cfu/g




                                                          Palisade Mesophyll
                                                                               Can pathogens be internalized into
                     Waxy Cuticle       Epidermis
                                                          Cells                           Spinach?
                                                                               • Yes, in seedlings but not in mature plants.

 Spongy                                                                        • Pathogens can find entry via natural
 Mesophyll
 Cells
                                                                                 openings and cut edges

                                                                               • Internalization only part of the problem

                                                                               • Is vacuum cooling safe?
                      Cross Section of Unwashed Leaf




  Foodborne Illness Outbreaks Linked to Tomatoes
                                                                                Inoculate Flowers of Growing Plants
Salmonella                   Year Total                       Deaths
  serotype                          cases
                                                                                                              Screen for Salmonella
Javiana                      1990                   174            0                   0.1 ml 7 log cfu/ml
                                                                                                              External and Internal
Montevideo                   1993                    84            0
Baildon                      1998                    85            3
Javiana                      2002                   141            0
Newport                      2002                   297            0
Beranderup                   2004                   561            0
Javiana
Typhimurium                  2006                   181            0                  Variety: Abigail VFFT


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                          Fresh Produce and Human Pathogenicity
                                    Prof. Keith Warriner, University of Guelph
                                           A Webber Training Teleclass
Serovar             Total           Surface        Internal
                    Batches         (% Positive)    (% Positive)       Survey of Tomato Growing
                    Tested
                                                                      Regions in Florida and Mexico
Javiana 5913        15              8 (53%)        4 (26%)
                                                                   • Salmonella Montevideo
Javiana 6027        15              14 (93%)       6 (40%)
                                                                   • Salmonella Javiana
Montevideo          10              4 (40%)        9 (90%)         Soil
Newport             9               7 (78%)        4 (44%)         Water
Enteritidis         9               3 (33%)        1 (11%)         Packing plant
Senftenberg         10              5 (50%)        0               Feces of wild animals
Typhimurium         8               3 (38%)        0
Hadar               9               7 (78%)        5 (56%)         Human pathogens adapted to environments
                                                                    outside the host?
Infantis            11              4 (36%)        1 (1%)
Dublin              9               7 (78%)        2 (22%)




                 Sprouted Seeds                                        Sakai City, Japan, in 1996
   • Ontario 2005                                                  Radish sprouts contaminated with
    > 600 cases of salmonellosis linked to                         E. coli O157:H7.
     mung bean sprouts

                                                                   >6000 cases 13 deaths
   34 outbreaks linked to alfalfa and other
     sprouted seeds since 1990
                                                                   Further 4000 cases reported in other cities
   Contaminated seed implicated in majority of
    cases




           Sprout Outbreaks 1996-2004
                                                                         Seeds are Main Source of
   Year        Alfalfa    Clover          Mung        Cases
                                          Bean                                  Pathogens
   1996       1           1                        650
   1997       3           1                        277
   1998       3           1                        48
   1999       5           2                        389
   2000       -------     -------         1        75
   2001       1                           2        88
   2002       1                           1        21
   2003       5                                    52
   2004       2                                    33
   Total: 27 Outbreaks                    1633 Cases

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                                        Fresh Produce and Human Pathogenicity
                                            Prof. Keith Warriner, University of Guelph
                                                   A Webber Training Teleclass
     Growth of E. coli during mung                                                   Apoplastic Fluid from Surface
           bean sprouting                                                              Sterilised Bean Sprouts

TVC
E. coli
                           10
                                                                                       Live Bacteria                   Dead Bacteria
                           8                                Wash
            Log 10 cfu/g




                           6
                                                            Surface Sterilised
                           4                                20, 000ppm
                                                            hypochlorite
                           2


                           0
                                0   1    2          3   4     5
                                         Tim e (Days)




                                                                                          Seed Decontamination
                                                                                 •   Calcium hypochlorite
 Sprouts derived from inoculated beans                                           •   Acidified sodium chlorite
                                                                                 •   Peroxyacetic acid + hydrogen peroxide
                                                                                 •   Hot water pasteurization
                                                               Control           •   Heat treatment
                                                                                 •   Irradiation
                                                                                 •   Calcinated Calcium
                                                                                 •   Organic acids
                                                                                      All have failed to successfully decontaminate seeds
                                        GUS Assay                                    without adversely affecting seed germination.




          Why are seeds so difficult to
                                                                                              Different Approach
               decontaminate?
  • Protective sites on the seed coat                                            Seed
                                                                                                            Include Sanitizer
  • Low number of survivors (<1 MPN/g) can                                       Decontamination
    proliferate during the first 24h of sprouting.                                                                      Soak Seed
  • Need to preserve seed viability                                                  Soak Seeds

                                                                                                              •Extended contact time
                                                                                     Sprout Seeds             •Pathogens released from
                                                                                                               protective sites
                                                                                       Harvest


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                        Fresh Produce and Human Pathogenicity
                              Prof. Keith Warriner, University of Guelph
                                     A Webber Training Teleclass
    Calcium Hypochlorite (20, 000ppm) Vs
           Germin-8-or (200ppm)
                                                                     Botulism Carrot Juice
Treatment of mung     E. coli O157:H7       Salmonella
      beans                                                • 6 cases (4 USA; 2 Toronto)
                    Count    Enrichment Count Enrichment
                    Log                 Log
                    cfu/g               cfu/g              • 28 cases per year
Calcium              8.59         NT     7.96     NT
hypochlorite                                               • Home canning
 (20, 000ppm,                                              • Vegetables in oil
20mins)
Germin-8-or           ND          ND     ND       ND
(200ppm)


 Initial loading: 3-4 log cfu/g         ND <1 cfu/25g




          Clostridium botulinum                             • Loss of muscle
                                                              function
•   Gram positive anaerobic rod.                                                  -
                                                            • Incubation period: 18
                                                              36 hours
•   Forms resistant endospores
                                                            • Symptoms:
•   Temperature range:                                      Loss of muscle activity
•   Proteolytic 10-48˚C (opt 37˚C)                          Weakness in eye
•   Non-proteolytic 3.3-45˚C (opt 30˚C)                       muscle
                                                            Slurred speech
•   aw min: 0.93                                            Difficult swallowing,
•   pH min: 4.6                                               breathing and moving
                                                              limbs.




    Possible Sequence of Events
Botulism spores in soil
Pasteurization:-
• Inactivated natural anti m
                         - icrobial constituents                         Future Directions
• Reduction in competitive microflora
• Activation of spores
• Outgrowth of Cl. botulinum with product held at
  elevated temperatures.




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                              Fresh Produce and Human Pathogenicity
                                 Prof. Keith Warriner, University of Guelph
                                        A Webber Training Teleclass

Lettuce Safety Initiative (Aug 2006)                                       Post-harvest Intervention
                                                                      • Can contamination in the field be
 •   Review current procedures
                                                                        prevented? No
 •   Rapid response to outbreaks
 •   Documentation (on-farm HACCP)
                                                                      • Is testing the answer? Yes, but cannot
 •   Introduce regulations                                              provide total assurance.

                                                                      • Washing is ineffective




                                                                          Synergistic Action of UV and
Decontamination of Fresh Produce                                              Hydrogen Peroxide

    -
• Pre        a
            Wsh: Potable water to remove visible soil

Biocidal wash
• 200ppm sodium hypochlorite
• Organic acids
• Peroxyacetic acid
• Acidified Sodium Chlorite
• Ozonated water




 Inactivation of Different Bacteria on Agar Plates                              Prototype System

                                        Log Count Reduction                                                 Lamp
           Bacterium            UV254   UV254     UV254       UV254                                         LP 12W
                                         1%       1.5%         2%                                           254nm
                                        H2O2      H2O2        H2O2
Pectobacterium carotovora       2.25     ND        ND          ND
Escherichia coli O157           2.83     4.20      ND          ND
Pseudomonas fluorescens         2.50     4.60      ND          ND                                           Spray Heads
Salmonella Montevideo           0.52     4.97     4.75        4.84
Aeromonas hydrophila            2.32     ND        ND          ND
                                                                                                            Sample
Listeria monocytogenes           ND      ND        ND          ND
                                                                                                            Tray
 Initial loading 6 log cfu
 ND Not Detected




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                         Fresh Produce and Human Pathogenicity
                                 Prof. Keith Warriner, University of Guelph
                                        A Webber Training Teleclass

                                                                      Electrolyzed Water
Spinach         Log Count Reductions                     • Generates chlorous
                External      Internal                     acid
Escherichia coli O157:H7
UV:H2O2         4.75 ± 0.85   0.63 ± 0.15                • 2 log cfu reduction in
                                                           lettuce inoculated with
Hypochlorite    0.46 ± 0.07      .05
                              - 0 ± 0.01
                                                           Salmonella
Salmonella
UV:H2O2         3.65 ± 0.12   0.89 ± 0.18
Hypochlorite    0.48 ± 0.08      .34
                              - 0 ± 0.34




                                                                            Castillio Texas A & M University

    Irradiation
• Cobalt 60

  - eam
• E b

• Consumer
  acceptance?




              Castillio Texas A & M University




                                                                          Final Thoughts




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                    Fresh Produce and Human Pathogenicity
                           Prof. Keith Warriner, University of Guelph
                                  A Webber Training Teleclass
• Fresh produce represents a continuing food                      The Next Few Teleclasses
  safety issue.
                                                    February 21     Infection Control in the Endoscopy Clinic
                                                                    … with Dr. Richard Everts, Nelson Marlborough Health Service
• One outbreak is one too many
                                                    February 22     Best Practice for Hospital Construction Management
                                                                    … with Andrew Streifel, University of Minnesota

• Greater understanding on routes by which          March 6         Tuberculosis in the Modern Age
  human pathogens enter and disseminate                             … faculty to be announced

  through produce chain                             March 8         Voices of CHICA
                                                                    … with CHICA-Canada Board Members & Guests

                                                    March 22        A Year of Cleaner, Safer Care – A Worldwide Experience
• Focus on interventions                                            … with Dr. Didier Pittet, World Health Organization, Geneva



• Regulation (Industry or Government led)?          For the full teleclass schedule – www.webbertraining.com
                                                       For registration information www.webbertraining.com/howtoc8.php




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                             www.webbertraining.com                                                                   Page 20

								
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