Procedure for the Development and Management of Food Microbiological Methods

Development of Methods
Part 2, Section B, Qualitative Methods
June 2008

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Part 2. Data Requirements and Submission Templates for Methods

Microbiological Methods Committee
Evaluation Division,
Bureau of Microbial Hazards,
Food Directorate,
Health Products and Food Branch,
Sir Frederick G. Banting Research Centre [PL 2204E]
Ottawa, Ontario, K1A 0K9
e-mail: Don_Warburton@hc-sc.gc.ca

1. Purpose

To define the data requirements and provide the templates needed for submissions of data created in the development or validation of food microbiological methods for inclusion in The Compendium of Analytical Methods.

This document is divided into two Sections:

Section A: Data requirements, submission templates, and examples for Quantitative Methods.

Section B: Data requirements, submission templates, and examples for Qualitative Methods.

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Section B: Data Requirements, Submission Templates, and Examples for Qualitative Methods

1 Template for the Review of Qualitative Methods by the Microbiological Methods Committee Technical Group

Note: Technical Group (TG) members should consult the appropriate section of the Development of Methods found in Part 4 Guidelines for the Evaluation of Quantitative Food Microbiological Methods for specific validation requirements for a new method.

The following must be provided in each submission:

Method or Procedure (full title of method including target species):

Originator (identify all data sources):

Technical Group Name:

Members of Technical Group (names, titles and affiliations of all members):

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Documents provided for review
Documents, data, reports, letters, articles, methods etc. which were provided by the MMC to conduct the review. These documents must include at a minimum the validation protocol used, detailed raw data and summary data in the format specified in Procedures for the Development and Management of Food Microbiological Methods.

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Additional documents consulted
References for additional material consulted or used during the course of the review (e.g., ISO 16140:2003, Health Canada documents, previous decisions, The Compendium of Analytical Methods, journals, books, other reviews of the method, etc.). Perform a search to determine if other reviews are available and if the method holds status from other international organizations.

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Component	Observations, comments, questions
1. SUBMISSION INFORMATION
Title of method or procedure
Aim of the review (to obtain MFLP or MFHPB status or?)
Reviewed by
Date submitted
Date evaluation completed
2. GENERAL INFORMATION
Data generating lab is ISO accredited?
Does method have potential for meeting the standards of a regulation? For example, is the target organism appropriate, is the LOD acceptable, does it reduce the Turn Around Time (TAT) of the standard method etc.
Has an evaluation been conducted in at least one Canadian government laboratory?
Is data accompanied by quality control data e.g., lot codes, controls?
Inclusivity At least 50 target organisms (100 for Salmonella), if possible? Do the organisms originate from food? Is the food specified? Is there sufficient characterisation of the organisms? Are the organisms sufficiently different biochemically, serologically, genetically and geographically? Alternative method should detect ≥98% of those detected by reference method
Exclusivity Are exclusivity tests performed with at least 30 organisms related to target organism, if possible? Does the list include species and/or strains likely to interfere with the target organism? (e.g., alternate method should NOT detect >9.6% of the species tested)
How many naturally contaminated samples were tested?
Appropriate number of inoculated samples? Were they inoculated at fractional positive target organism levels? Did inoculated samples contain typical background organisms? Was the inoculating method adequate?
Were the samples suitably different from one another? Were there sufficient positive and negative samples?
Which food categories were tested? Categories (dairy, meat, fish and seafood, confection and bakery, fruit and vegetables, feeds, environmentals) and number For approval for multiple foods, six categories should be tested (if appropriate, including environmentals) Are a variety of processing treatments represented? Are there sufficient food types in each group?
Has Limit of Detection (LOD) been determined? Can the arithmetic be followed? (Based on spiking studies or method comparison.) LOD should be at least three to five cfu/25 g, equal to or better than the reference method or able to detect ≤ three cfu per g, or fit-for-purpose.)
Are a reasonable number (~five) of different spiking organisms used?
What is the spiking protocol? Were the spiked organisms acclimatized in the food before testing? Are a number of different levels of spiking carried out?
What is the stressing protocol used? Is effectiveness quantified or described? Is it appropriate to the food tested?
Is the reference method provided? internationally recognised? equivalent to HC methods? is a rationale provided if a Compendium method was not the chosen reference method?
Were all positives confirmed regardless of whether they originated from the reference or alternative method?
Were all negatives "confirmed" (to a resonable point) regardless of whether they originated from the reference or alternative method?
Were the samples split rationally at the divergence between the reference and alternative methods?
Do the Relative Method Parameters conform to the standards? Standard Sensitivity ≥98% Specificity ≥90.4 False negative rate <2% False positive rate <9.6% Efficacy ≥94%
Relative Method parameters by category (see above for standards)
Absolute Method parameters If an absolute validation - is the method fit for purpose (e.g., LOD, supports claims in application of method etc.)
Other salient points

 

2 Microbiological Methods Committee Technical Group
Review of Qualitative Methods - Summary Report

Concerns
Number and title concerns and explain them thoroughly, e.g., missing information, identification of authors and labs, thoroughness of data.

Recommendations
Overall summary of what the data and documents presented can justify and a final recommendation of the next course of action including recommendation for HPB Method (MFHPB), or Laboratory Procedure (MFLP) status or the requirement for more information or study.

Final decision may be made on the balance of evidence rather than the existence of each and every factor outlined. Be specific about any data that is being requested to resolve deficiencies or differences.

As a member of the technical group designated by the Microbiological Methods Committee (MMC), I have reviewed the presented data and material and agree with the recommendations presented.

_______________	Accept method for publication as a MFLP method
_______________	Accept method for publication as a MFHPB method
_______________	Accept method for publication as a MFLP or MFHPB method with the following modifications or stipulations:
_______________	Reject method for publication for the following reasons (please cite what information/data is missing or needed for reconsideration):
_______________	Other recommendation:

Signature
Signature of each of the technical group members. Approval can be done electronically, so actual signatures are not necessary. If there is not total consensus to the report, those not agreeing will have to provide sound scientific reasoning.

1. Name ____________	Title ____________	Signature ____________	Date ____________
2. Name ____________	Title ____________	Signature ____________	Date ____________
3. Name ____________	Title ____________	Signature ____________	Date ____________
4. Name ____________	Title ____________	Signature ____________	Date ____________
5. Name ____________	Title ____________	Signature ____________	Date ____________

3 Example of Data Qualitative Method Study and Instructions for Completing the Table

4 Example of a Completed Data Summary with Criteria for a Qualitative Study

1. Provide data from as many sources as possible, and provide details of each study. If submitting AOAC data do not include fractional positives in the table below. Submit fractional positive data separately in the AOAC format.
   
   
2. If the submission is for "multiple foods": Supply information for a minimum 60 positives and 30 negatives for each food category (dairy, raw meat, processed meats, vegetables, etc.) with a minimum total of 360 positives and associated negatives (a minimum of 180 negatives) for 6 different types of categories. If the submission is for "multiple foods and environmental samples" then you must also include environmental samples. If possible, ensure that at least 3 food types are included for a specific category. If the submission contains more than one matrix (eg., milk and cheese) of the same commodity (eg., dairy), then supply a minimum of 20 positives and 10 negatives for each type. See Example 1 - Data Submitted for Multiple Foods.
   
   
3. If the submission is for only one food category: For example, if your submission is for dairy only, then supply information on 60 positives each from at least 6 different matrices in that commodity (i.e. raw milk cheese, processed cheese, ice cream, yogurt, etc.). See Example 2 - Application for One Food Commodity. If the method targets environmental samples only then provide data as if the submission is for one food commodity.
   
   
4. Calculate the criteria for each food type using details on the Criteria Calculation Sheet. The review of the submission will examine the results for each matrix.
   
   
5. Ensure that the application statement matches the provided validation data.

5 Blank Table for Qualitative Comparative Method Study

6 Blank Table for Data Summary and Criteria Calculation

7 Criteria Calculation Sheet

A (positives) =
B (false positives) =
C (false negatives) =
D (negatives) =
Total (A+B+C+D) =

Quality Calculated	Formula	Ratio	Value as Percentage
Sensitivity	A/(A+C)
Specificity	D/(B+D)
False positive rate	B/(B+D)
False negative rate	C/(A+C)
Test efficacy	(A+D)/(A+B+C+D)