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A CLEARER PATH FOR PATHOGEN TESTING

A CLEARER PATH FOR PATHOGEN TESTING. HOST Bill McDowell Editorial Director, Meatingplace MODERATOR Tom Johnston Editor, Meatingplace. WHAT IS ACHIEVABLE IN PATHOGEN TESTING?. Gary R. Acuff Professor , Food Microbiology Head , Department of Animal Science.

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A CLEARER PATH FOR PATHOGEN TESTING

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  1. A CLEARER PATHFOR PATHOGEN TESTING

  2. HOST Bill McDowell Editorial Director, Meatingplace MODERATOR Tom Johnston Editor, Meatingplace

  3. WHAT IS ACHIEVABLE IN PATHOGEN TESTING? Gary R. Acuff Professor, Food Microbiology Head, Department of Animal Science

  4. Poll QuestionWhat is really achievable in pathogen reduction?1. It depends upon how much contamination is present. 2. 3 Logs. 3. A scientific endpoint is needed. 4. Complete elimination of pathogens.

  5. Pathogens • Enterohemorrhagic Escherichia coli • O157:H7 • Non-O157 • Salmonella • Campylobacter? • Focus on EHECs

  6. Source • Cattle • Gastrointestinal tract • Anything in close proximity to feces • Hide • Hooves • Dust • Water

  7. Control Opportunities • Genomics • Livestock production & feedlot • Handling and well-being issues • Slaughter • Fabrication • Retail • Consumer, foodservice

  8. Control Opportunities • Genomics • Livestock production & feedlot • Handling and well-being issues • Slaughter • Fabrication • Retail • Consumer, foodservice Where are the hazards most effectively addressed?

  9. Control Opportunities • Genomics • Livestock production & feedlot • Handling and well-being issues • Slaughter • Fabrication • Retail • Consumer, foodservice Where are the hazards most effectively addressed?

  10. Consumer Education

  11. Carcass Interventions Temperature Chemical

  12. Laboratory Challenge • Parallel evaluations • Marker pathogens in fecal material • Salmonella serotype Typhimurium • Escherichia coli O157:H7 • Non-inoculated fecal material • Indicator organisms Feces Feces plus Pathogens

  13. Log Reduction of E. coli O157:H7 and S. Typhimurium on Beef Carcass Surfaces

  14. Log Reduction of E. coli O157:H7 and Coliforms on Beef Carcass Surfaces

  15. What Is Realistic? • Elimination? • Reduction? • The real issue: What remains? • And where is it?

  16. Trimming and grinding processes will distribute any remaining pathogens.

  17. Unfortunate Event • Adulterant declaration • Well-intended (possibly), but short-sighted • “Zero” doesn’t exist in bacterial enumeration • Unintended consequence - difficult to measure improvement or control

  18. What is really achievable? • Does it really matter? • It all has to be gone. • Attempt to achieve what is required. • Absence is unreasonable (impossible, illogical, unscientific, other favorite adjective).

  19. An Endpoint is Needed • How can one aim for a target that does not exist? • Or one that constantly changes?

  20. Food Safety Objective • The maximum frequency and/or concentration of a hazard in a food at the time of consumption that provides or contributes to the appropriate level of protection.

  21. Food Safety Objective • H0 - ∑R + ∑I ≤ FSO • FSO = Food Safety Objective • H0 = Initial level of the hazard • ∑R = Total (cumulative) reduction of the hazard • ∑I = Total (cumulative) increase of the hazard • FSO, H0, R and I are expressed in log10 units

  22. Food Safety Objective H0 - ∑R + ∑I ≤ FSO 3 - ∑R + 0 ≤ -2 3 - ∑R ≤ -2 ∑R ≤ -5 ∑R ≥ 5

  23. 5-Log Reduction H0 - ∑R + ∑I ≤ FSO 3 - ∑R + 0 ≤ -2 3 - ∑R ≤ -2 ∑R ≤ -5 ∑R ≥ 5

  24. Reduction of E. coli O157:H7 and S. Typhimurium on Beef Surfaces by Sequential Pre- and Post-chill Lactic Acid Sprays

  25. Microbiological Testing • In the absence of an FSO, it is necessary to establish default criteria. • “Safe Harbor”

  26. Microbiological Testing • Where are we going? • Is there an end? • Is more sampling the answer?

  27. Microbiological Testing • In the ICMSF scheme for managing risk, two uses for criteria are identified... • To validate that control measures meet performance criteria • To determine acceptability when no more effective means of providing assurance is available (i.e., in the absence of knowledge that HACCP has been properly applied)

  28. Microbiological Testing If there is a way out, this may be it. • In the ICMSF scheme for managing risk, two uses for criteria are identified... • To validate that control measures meet performance criteria • To determine acceptability when no more effective means of providing assurance is available (i.e., in the absence of knowledge that HACCP has been properly applied)

  29. Poll Question ResultsWhat is Really Achievable in Pathogen Reduction?1. It depends upon how much contamination is present. 2. 3 Logs. 3. A scientific endpoint is needed. 4. Complete elimination of pathogens.

  30. Provide a scientific endpoint and the industry will achieve the necessary reduction.

  31. Food Safety At every step, 3M Food Safety is dedicated to protecting your brand and improving your productivity. Risk Reduction. Tools that provide trusted data for making informed decisions. Operational Efficiency. Reduce overtime and downtime - increase productivity. Competitive Edge. Solutions that create a powerful brand and impact your bottom line. www.3M.com/foodsafety/MMW

  32. CURRENT BEEF INDUSTRY SAMPLING AND TESTING PROGRAMS FOR E coli O157:H7 Timothy P. Biela EVP Food Safety & Quality AFA Foods

  33. Poll Question Which best describes your position? Packer Processor Other Are you currently testing the following products for E coli O157? Trim YES or NO Ground Beef YES or NO

  34. What are we doing and why? • Carcass Testing • USDA Mandated carcass testing • Boneless Beef Trim Testing • N60 Sampling and Testing • Sub-lot size varies from 1 to 5 combo bins • Raw Ground Beef Testing • Commercial versus Retail Testing Programs

  35. Food Safety Verification for O157 • Verification of HACCP and Food Safety Program for control of Enteric Pathogens • Must define the sublot • Must define the sample size and frequency of sampling • Must define the actions to be taken in the event of a positive result

  36. Total-N60 Platform“The Food Safety Umbrella” • Sample units of n=60 per ‘lot’ provides robust statistical basis. • Statistical confidence of N60 testing is at least 95.0% probability that ECH7 will be detected if present [assuming a population prevalence rate of 5.0% or higher]. • Surface Slice vsSubSurface Tissue • Surface Area – N60 examines substantially more total surface area of external surface tissue vs other trim or final-grind sampling methods. • Dilution Effect – Thin surface slices vs ‘sterile’ underlying tissue or ground meat gives increased probability of detection. • 5X more sensitive than finished ground beef sampling. • Lab method sensitivity – capable of detecting 15 cfu/375g, 100% of the time. • 1:5 enrichment media [vs 1:10 standard] improves sensitivity. • PCR-BAX initial screening using ‘modified-enhanced’ methodologies provides +90% accuracy. This slide courtesy of “others”. For Example only.

  37. N60 Sampling • 60 individual samples are taken from the lot • Preference is to sample surface material • Samples should be taken randomly across the entire “stream” or population of meat • Various sizes are used; 1x3, 2x5, etc…. • Lot sample size must be a minimum of 375 g • The entire sample should be analyzed

  38. References • Beef Industry Food Safety Council Best Practices • http://bifsco.org/harvest.aspx • USDA FSIS • http://origin-www.fsis.usda.gov/PDF/Draft_Guidelines_Sampling_Beef_Trimmings_Ecoli.pdf • International Commission on Microbiological Specifications for Foods (ICMSF) • http://www.icmsf.iit.edu/publications/sampling_plans.html

  39. Microbiological Testing Programs must have: • A robust sampling plan that is designed to meet the microbiological testing objectives with a high degree of confidence. • The adequacy of the sampling plan should be evaluated by an independent third party. • In order to ensure the interpretability of testing results, the sampling plan must be implemented correctly. • Based on the results of microbiological testing, actions must be taken. (Plan / Do / Check / Act)

  40. Key Elements of Sampling Plans • Define what constitutes a sample, • Define the number of samples to be collected, • Define how samples will be collected, • Define the number of samples it will collect, • Define the frequency of sample collection, • Define the procedures used to analyze samples and, • Define the criteria for signaling an out-of-control process

  41. Key Elements of Sampling Plans (2) • Ensure that samples collected are representative of the entire population; minimize bias, • Ensure that the sample size is sufficient to provide the desired level of confidence. • Ensure the sampling plan addresses the fact that pathogens are heterogeneously distributed • Ensure that sampling considers the variability in prevalence rates over time (seasonal variation).

  42. Food Safety Verification for O157Example #1 • Major Retailer w Grinding Operation: • One sample every two hours of production. • Samples are analyzed with PCR/DNA. • Positive products are diverted to further processing. • Positives are bracketed from one hour in front of first positive to end of the day. • Positive rates range from .4 to .7%.

  43. Food Safety Verification for O157Example #2 • Major Integrated Fed Beef Packer • Format varies from one sample per hour to one sample every fifteen minutes to screening pre-ground products prior to packaging. • Samples are analyzed with PCR/DNA. • Positives are bracketed from one hour in front of first positive to one behind and subjected to intensified sampling. • Positive rates range from .4 to .7%.

  44. Food Safety Verification for O157Example #3 • Major Quick Service Restaurant • One sample taken for every batch of ground beef formulated. • Samples are composited for four batches. • Composites are sampled and a 25 gram analyte is tested. • Positives are bracketed from one hour in front of first positive to end of the day. • Positive rates have ranged from 0 to .2%.

  45. HACCP and Risk Assessment for Raw Ground Beef Products • Retail versus Commercial Ground Beef • Retail • Consumers; Families • No identified platform for cooking • No verification of cooking controls • Commercial • Quick Serve and Casual Dining • Specific platforms for cooking and controls

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