1 ©2016, G.R. Acuff Process Validation Pathogens, Indicators or Surrogates Gary R. Acuff Director, Texas A&M Center for Food Safety Professor, Food Microbiology

2 ©2016, G.R. Acuff Validation  Does your process control actually work? How well?

3 ©2016, G.R. Acuff How to Use the Data  Performance 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.  Performance 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.

4 ©2016, G.R. Acuff Performance Objective  H 0 - ∑R + ∑I ≤ PO  PO = Performance Objective  H 0 = Initial level of the hazard  ∑R = Total (cumulative) reduction of the hazard  ∑I = Total (cumulative) increase of the hazard  PO, H 0, R and I are expressed in log 10 units  H 0 - ∑R + ∑I ≤ PO  PO = Performance Objective  H 0 = Initial level of the hazard  ∑R = Total (cumulative) reduction of the hazard  ∑I = Total (cumulative) increase of the hazard  PO, H 0, R and I are expressed in log 10 units

5 ©2016, G.R. Acuff Performance Objective H 0 - ∑R + ∑I ≤ PO 3 - ∑R + 0 ≤ ∑R ≤ -2 ∑R ≤ -5 ∑R ≥ 5

6 ©2016, G.R. Acuff Validation  Does your process control actually work? How well?  Qualitative end product sampling provides insufficient information.

7 ©2016, G.R. Acuff Ideal Situation  Validate Process Control  Measure hazard (pathogen) presence  Pre- and post-CCP  Primary focus  Final product  Also helpful  Requires sufficient levels of pathogen

8 ©2016, G.R. Acuff Example: Validation of Beef Carcass Interventions  Pathogen presence on carcass surface  Inconsistent  Low levels  Insufficient for confirmation of process control  A measureable alternative?  Indicator bacteria  Aerobic Plate Count (APC), Lactic acid bacteria, Enterobacteriaceae, coliforms, fecal coliforms, E. coli, enterococci

9 ©2016, G.R. Acuff Example: Log Reduction of E. coli O157:H7 and Aerobic Plate Count (Feces) on Beef Carcass Surfaces Log Reductions

10 ©2016, G.R. Acuff Example: Log Reduction of E. coli O157:H7 and Coliforms (Feces) on Beef Carcass Surfaces Log Reductions

11 ©2016, G.R. Acuff A more consistent alternative…  Surrogates  American Type Culture Collection (ATCC)   Biosafety Level 1  Tested against salmonellae & STECs  Accession numbers  BAA-1427 to BAA-1431  Non-pathogenic Escherichia coli Surrogates Indicators Panel (ATCC MP-26)  Why ATCC?

12 ©2016, G.R. Acuff Available Options  Presence/absence of hazard (pathogen)  Detect naturally occurring traditional indicator bacteria  Inoculate and measure reductions  Traditional indicator bacteria (source?)  Surrogates (AskFSIS)

13 ©2016, G.R. Acuff

14 ©2016, G.R. Acuff Validate Process Control  Enumeration of naturally-occurring hazard before and after CCP  Inoculate with hazard  Inoculate with surrogate  Enumerate indicators before and after  Research study conducted in facility  Reference published journal article Increasing Strength