1. 1
Useful Microbiological
Testing in Food Safety &
Quality Management
Katherine M.J. Swanson, Ph.D.
Vice President Food Safety Ecolab
President-Elect IAFP
Arkansas Association for Food Protection
Springdale, AR
September 14, 2011

2. 2
Discussion Topics
 International Association for Food Protection greeting
 Different tests serve different purposes
 Testing for maximum value

3. Our mission is working
To provide food safety professionals
worldwide with a forum to exchange
information on protecting the food supply

4. IAFP Executive Board 2011-2012
President-Elect Past President
Katie Swanson Lee-Ann Jaykus
Ecolab, Inc. North Carolina
State University
Affiliate Council
Chair
Vice-President
Gloria Swick-
Don Schaffner
President Brown
Rutgers
Ohio Dept. of
University Isabel Walls
Health (retired)
Executive
Secretary Director
Don Zink David Tharp
US FDA IAFP

5. IAFP Annual Meeting
the leading food safety conference

6. European and International Symposia
European
2012 Warsaw, Poland
2011 Ede, The Netherlands
2010 Dublin, Ireland
International
2012 Latin America - Argentina
2011 Asia Pacific - Australia
2010 Latin America - Colombia

7. IAFP Publications

8. Affiliate Connections
48 Affiliates worldwide
 North America – 35
 South/Latin America – 3
 Europe – 4
 Asia – 4
 Australia & Oceania – 2
Connect with food safety professionals in your
area by joining or forming an IAFP Affiliate!

9. Service and Growth Opportunities
Committees
 Standing Committees
 Special Committees
 Task Forces
Professional Development Groups (PDGs)
 Diverse focus groups in 20 specialized areas
Affiliate Council
 Delegates from 48 Affiliate organizations, with
representation on IAFP Executive Board

10. Recognition for Achievements
 Black Pearl Award
 Awards for excellence in specific disciplines of
food safety – 10
 Travel Awards for government employees – 4
 Association honors – 4
 Cooperative Awards – 3
 Student Awards and scholarships – 13
 Affiliate Awards – 5

11. Benefits of Membership
 IAFP Report monthly newsletter
 Online membership directory & FPT
 Involvement in Committees and Professional
Development Groups
 Discounted rates for:
 IAFP’s scientific journals
 IAFP annual meeting and international symposia
 Educational workshops
 Food safety booklets, icons, and other established
resources
 3-A Sanitary Standards

12. Flexible Membership Plans
Base Membership
$55
Base Membership for Students
$27.50
www.foodprotection.org

13. 13
Different Tests Serve Different
Purposes

14. 14
Microbial Testing
 “Microbial testing” means
different things to different
people
 Reams of data
 Detective game to identify unknown or
causative agent
 Presence/absence or qualitative
reaction that’s observed
 Quantitative measurement of the
microbiological status of a sample or
OR
lot
Presentation focuses on process
control and product acceptance

15. 15
The Purpose of a Test Determines:
The target Indicator or pathogen
The method Time to results, accuracy, repeatability, etc.
Environment, line residue, end product, location
The sample collected, size/ number of samples
The frequency Daily, weekly, monthly, etc. or event triggered
The interpretation Investigational, routine, regulatory, etc.
Rejection, process adjustment, recall, outbreak
The action investigation, etc.

16. 16
International Commission on Microbiological
Specifications for Foods
 Founded in 1962 to advance scientific concepts for
government and industry consideration to:
 Reduce foodborne illness
 Facilitate global food trade
 Focus on testing applied to foods
 Membership
 6 Academia, 6 Government, 5 Industry from 11 Countries
 All work is voluntary and without honoraria
 Partners with FAO, WHO, ILSI, IUFoST, IAFP etc.
 Provides advice through books, papers, workshops, etc.
 Advice has no official status

17. 17
When & Where to Test for Food
Safety Management
 When there is good evidence that:
 There is a microbiological problem
- Food safety or quality
- Historical or current
AND
 Testing will help to control the problem

18. 18
Target Organism Examples
ICMSF Hazard Categories
EXAMPLES
Utility Spoilage, reduced shelf life, no Total counts, yeast, mold,
health concern etc.
Indicator Measure of GHP or process control Coliforms, generic E. coli,
Enterobacteriaceae, etc.
Moderate Not life threatening, short duration, S. aureus, B. cereus, C.
hazard self limiting, no sequelae perfringens, Norovirus, etc.
Serious Incapacitating, usually not life Salmonellae, Shigella
hazard threatening flexneri, Yersinia
enterocolitica, etc.
Severe Life threatening, chronic sequelae, E. coli O157:H7, C
hazard or long duration OR botulinum toxin or
Cronobacter (infants)
Designed for sensitive sub-
population
From ICMSF Book 7

19. 19
Key ICMSF Sampling Plan Terms
n Number of sample units analyzed
c Maximum number of sample units with
unsatisfactory test results
m Level that separates acceptable quality from
marginally acceptable or unacceptable quality
M Level above which is unsatisfactory or requires
further investigation

20. 20
Choosing m and M
m M
No concern Some Decisive concern
Relative proportion of
concern
sample units in a lot
Mean log count

21. 21
ICMSF Suggested Sampling Plans
FOR LOT ACCEPTANCE TESTING
Likely Change Before Consumption
Hazard Group Reduce No Change Increase
Utility Case 1 Case 2 Case 3
n=5, c=3 n=5, c=2 n=5, c=1
Indicator Case 4 Case 5 Case 6
n=5, c=3 n=5, c=2 n=5, c=1
Moderate Case 7 Case 8 Case 9
n=5, c=2 n=5, c=1 n=10, c=1
Serious Case 10 Case 11 Case 12
unit = 25g
Analytical
n=5, c=0 n=10, c=0 n=20, c=0
Severe Case 13 Case 14 Case 15
n=15, c=0 n=30, c=0 n=60, c=0

22. 22
Sample Size Influence on Probability
of Acceptance
m=0
1.2
Probability of Acceptance
86% n = 15
1
74% n = 30
0.8 55% n = 60
0.6
0.4
0.2
0
0 1% 5 10 15 20
% Defective

23. 23
Testing to Maximize Value

24. 24
Useful Microbial Testing
 Identification of contamination sources
 Environmental monitoring to identify potential harborage
sites
 Utility and indicator organisms to verify effective controls &
trends
 Effective processing
 Effective control of post process contamination
 Investigation sampling for problem solving

25. 25
Process Example
Process 1 Packaging Line A
Ingredients Process 2
Packaging Line B
Process 3
What action do you take when an unacceptable result is
found on Line B?

26. 26
Result Format Influences Information
Provided
Presence/Absence Quantative
5
Positive
4
Log (CFU/g)
3
2
1
Negative 0
0 10 20 0 10 20
Lot Number Lot Number

27. 27
Trend Analysis Can Inform Process
Control 5 5
4 4
Log (CFU/g)
Log (CFU/g)
3 3
2 2
1
1
0
0
0 10 20
0 10 20
Lot Number
Lot Number
5 5
4 4
Log (CFU/g)
Log (CFU/g)
3 3
2 2
1 1
0 0
0 10 20 0 10 20
Lot Number Lot Number

28. 28
Testing Considerations
 Primary production
 Ingredients
 In-process
 Processing environment
 Shelf life
 End product

29. 29
Book 8 Contents
 Part 1-Principles  Part 2 – Product Categories
 Utility of microbial testing for  Meats
safety & quality  Poultry
 Validation of control measures  Seafood
 Verification of process control  Feed & pet food
 Vegetables
 Verification of environmental
control  Fruits
 Spices, dried soups, flavorings
 Corrective action to re-establish
control  Cereals
 Microbial testing in customer-  Nuts, oilseeds, dried legumes
supplier relationships  Cocoa and confectionery
 Oil based foods
 Sugar, syrups, honey
 Beverages
 Water
 Dairy products
 Eggs
 Shelf stable, heat treated foods
 Infants and young children
 Formulated foods

30. 30
Primary Production
 Included when production conditions
have a major influence on the
microbial quality or safety
 Fruits, vegetables, spices, meat, poultry and
fish products
 Examples of samples to consider
 Irrigation water
 Fertilizer
 Feed
 Other on-farm practices

31. 31
Ingredient Testing
 May be useful for some
applications and not others
 Example - cocoa powder:
Used in chocolate, no heat treatment
? Used in ice cream mix that is
subsequently pasteurized
 Question
 Is control at the ingredient step
necessary?

32. 32
In-Process Testing
 Verify a kill step or predict potential re-
contamination
 Examples
 Intermediate product, line residues, tailings,
wash water
 Typically indicators with quantitative results
 Questions:
 Is the process needed to control a microbial
concern?
 Is testing needed to verify:
- the process is functioning as intended or
- contamination is not occurring in the process?

33. 33
Processing Environment Testing
 Use to verify that the environment is
under appropriate hygienic control
 Examples
 Swabs or sponges for equipment or in the
environment
 Rapid testing to verify cleaning & sanitation
adequacy
 Identify harborage sites that can
contaminate end product
 Frequently, earlier detection of issues
than end product testing
 Questions considered:
 Does the environment need to be controlled
to prevent contamination?
 Will testing be beneficial to verify control?

34. 34
Shelf Life Testing
 Relevant for products subject to microbial spoilage
 Purpose – verify microbial stability for the product life cycle
 May predict issue before they are experienced in the
market place
 Questions considered:
 Is shelf life limited by a microbiological safety or quality concern?
 Is shelf-life testing feasible?

35. 35
End Product Testing
 Demonstrate successful application of controls or assess
the status of a lot when no other information exists.
 Alternative sampling plans may be appropriate, for
example:
 Fewer samples for on-going surveillance activity
 More samples when investigating significant process deviations or
outbreaks.
 Questions considered:
 Is end product testing necessary to verify the overall manufacturing
process?
 Is end product testing relied upon for ensuring the safety or quality of
the lot?

36. 36
Example: Dried Ready-to-Eat Cereal
Relative importance Useful testing
Critical Medium Test for mycotoxins if confidence in raw grains is low
ingredients Test nuts, cocoa, and other sensitive ingredients with no
subsequent kill step for Salmonella if confidence in supplier
is low.
In-process High Test appropriate product residues and in-line samples for
Salmonella. Typical guidance levels:
Salmonella – absent
Processing High Test for Salmonella and Enterobacteriaceae in the
environment processing environment Typical guidance levels:
Enterobacteriaceae – 100-1000 cfu/g
Salmonella – absent
Shelf-life Not -
relevant

37. 37
Example: Dried Ready-to-Eat Cereal (continued)
Relative
importance Useful testing
End High Testing for Enterobacteriaceae is recommended to verify process
product control.
Analytical Sampling plan & limits/g
Product Microorganism method Case n c m M
Dried Enterobacter- ISO 2 5 2 10 102
cereal iaceae 21528-2
Low Testing for pathogens is not recommended during normal
operation when GHP and HACCP are effective as confirmed by
above tests. When above testing or process deviations indicate a
possible safety issue, test for Salmonella.
Sampling plan &
Analytical limits/25g
Product Microorganism method Case n c m M
Dried Salmonella ISO 6579 11 10 0 0 -
cereals

38. 38
Example: Comminuted Meat
Relative importance Useful testing
Critical Low to Pre-testing beef trimmings for E. coli O157:H7 may be
ingredients high useful when confidence in supplier control is low.
In-process Low Routine in-process samples are not normally collected.
Samples of meat at various stages of processing can be
used to establish a baseline and understand changes in
the microbial population during processing.
Processing Low Sample equipment surfaces before start-up to verify
environment efficacy of cleaning and disinfecting. Typical levels
encountered may vary by surface type.
Shelf life Low Routine shelf life testing of refrigerated raw meat is not
recommended. Shelf life testing may be useful to validate
code dates of new retail products or when new packaging
systems are installed.

39. 39
Example: Comminuted Meat (continued)
Relative
importance Useful testing
End Medium Test freshly packaged product for indicators for on-going process
pro- control and trend analysis using internally developed guidelines.
duct Levels for processing do not apply during distribution or at retail.
Sampling plan &
Analytica limits/g
Product Microorganism l method Case n c m M
Raw, comminuted E. coli ISO 16649-2 4 5 0 0 -
meat
Medium Routine testing is not recommended for salmonellae. In regions
where ground beef is a continuing source of E. coli O157:H7 illness,
the following criteria are recommended.
Sampling plan &
Analytical limits/25g
Product Microorganism method Case n c m M
Ground beef E. coli O157:H7 ISO 16654 14 30 0 0 -

40. 40
Microbial Sampling Summary
 Testing
safety “into” products usually does not work
because of sampling probability
 Testing is recommended to generate meaningful data
 Impact quality or safety
 Verify appropriate controls or direct corrective action
 Focus on verification of process control preferred
 Environmental monitoring
 Selected sampling tailored to the line to verify control

41. 41
Acknowledgements
ICMSF
 Dr. Martin Cole, CSIRO, Australia  Dr. Russ Flowers, Silliker Group, United
(Chair) States
 Dr. Fumiko Kasuga, National Institute of  Dr. Bernadette Franco, Universidade de
Health, Japan (Secretary) São Paulo, Brazil
 Dr. Jeff Farber, Health Canada  Dr. Leon Gorris, Unilever, China
(Treasurer)
 Dr. Anna Lammerding, Public Health
 Dr. Wayne Anderson, Ireland Food Agency, Canada
Safety Authority
 Dr. Xiumei Liu, CDC China
 Dr. Lucia Anelich, Consumer Goods
Council, South Africa  Dr. Tom Ross, University of Tasmania,,
Australia
 Dr. Robert Buchanan, University of
Maryland, United States  Dr. Katie Swanson, Ecolab,
United States
 Dr. Jean-Louis Cordier, Nestle,
Switzerland  Dr. Marta Taniwaki, Instituto de
Tecnologia de Alimentos, Brazil
 Dr. Ratih Dewanti, Bangalore Agricultural
University, Indonesia  Dr. Marcel Zwietering Wageningen
University, The Netherland

42. 42
Ecolab
Ecolab Global Research, Development and Engineering
Eagan, Minnesota, USA