Microbiological Sampling

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A webinar presented by:

Dr Andy Bowles

Attendee Notes 10/10/2018

Microbiological sampling

Dr Andy Bowles

This webinar will consider

Why sample foods?

Legal framework

Approach to sampling

Sampling technique

Microbiological sampling

Why sample foods?

Legal framework

Approach to sampling

Sampling technique

1 10/10/2018

Purpose of Sampling

 Surveillance  FSA survey  Regional sampling  Verification  As part of routine inspection/audit  Compliance  Regulation 853/2004  Investigative  Complaint  Outbreak

Microbiological sampling

Why sample foods?

Legal framework

Approach to sampling

Sampling technique

Legal Framework

 Regulation (EC) 882/2004  “Official control”  Regulation (EC) 178/2002  Regulation (EC) 2073/2005  Food Safety and Hygiene (England) Regs 2013  Food Safety (Sampling and Qualifications) (England) Regulations 2013  Food Law Code of Practice  Food Law Practice Guidance

2 10/10/2018

Interventions

Official Controls Other interventions

inspections education

audits advice

sampling visits coaching

monitoring visits information and intelligence gathering

surveillance visits

verification visits

What is a sample?

 Sample : “Portion of an item which may or may not be representative of the whole item”

Representative sample

 “A portion of an item that has been taken in such a manner that inferences may be made regarding the microbiological flora or chemical composition of the whole item”

3 10/10/2018

Formal v Informal Samples

 What is a “Formal” sample?

Microbiological sampling

Why sample foods?

Legal framework

Approach to sampling

Sampling technique

Sampling Pitfalls

 Three main issues to consider to avoid problems:  Planning  Sampling technique  Continuity of evidence

4 10/10/2018

Planning

 Consider:  Targeting  What food is to be sampled  Quantity of sample required  Nature of target organism  Purpose of sampling  Follow up action

Targeting

 Consider targeting premises/importers:  where concerns have been raised about the ability of management to consistently produce safe food.  Poor confidence in management  High risk foods, inadequate controls  Low FHRS scores

Targeting

 Manufacturers  Consider scope and relevance of sampling  HACCP verification  Micro regs

5 10/10/2018

Quantity of Food

Two main issues:  Sample size adequate for examination? Normally 250g minimum Ask Food Examiner if in doubt

 Representative sample:  Microbiological criteria of foodstuffs regulations  5 samples normally taken  Depends on purpose of sampling

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Target Organism

 Depends on purpose of sampling  Not always known  Use of indicator organisms  Swabbing and sampling can be targeted  If in doubt - consult Food Examiner

Microbiological sampling

Why sample foods?

Legal framework

Approach to sampling

Sampling technique

6 10/10/2018

Taking Samples

 Samples should reach Laboratory:  Microbiologically unchanged from when sampled  Officers should take steps to:  Prevent Contamination by  Equipment  Officer  Environment  Prevent death/ growth of micro-organisms

Taking Samples

 Preventing Contamination by:  Equipment  Ideally use sterile tools etc  Single use preferable  Systems for storage/handling equipment  stock rotation

Sample pots

 Honey jars  Not tamper evident  Not sterile evident

 Tamper evident jars  Preferable

7 10/10/2018

Taking samples

 Preventing Contamination by:  Officer  Wash hands prior to sampling.  Rewash as necessary  Consider anti bacterial gels  Wear disposable sterile gloves  Not essential but desirable  Wear clean overalls  Take care to plan day to prevent cross contamination

Taking Samples

 Preventing Contamination by:  The Environment  Avoid placing containers etc onto surfaces  Sample intact unopened containers (where possible)  Clean outside of packaging with sterile wipes  Open packages sufficiently to allow easy sampling  Open sampling container immediately prior to sampling, reseal immediately after.  Use Ice in bags to cool samples, not crushed ice  Discard any suspect samples

Food Sampling Equipment...

 Screwdrivers  Scissors  Cardboard case cutter  Swabs/Sterile water  Pliers  Swab templates  Teaspoon  Large spoon  Dippers/ladles  Tongs  Plastic boards  Spatula  Corer  Pallette Knife  Hammer  Sharp knives  Scoop  Tweezers  Scalpels  Alcohol wipes  HOCl solution  Forks

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8 10/10/2018

Taking Samples

 Preventing death / growth of Micro-organisms  Careful use of sanitizers /wipes  Proper use of cool boxes

Taking Samples

 Solid / Frozen food:  Sterile knife, borer, auger or drill  Keep frozen

 Liquid products  Agitate/stir  If bulk - may need to sub sample then mix

Bulk Liquid Sampling (Tap)

Clean with detergent

Spray with HOCl or Alcohol

Run 5 Seconds

Sample

9 10/10/2018

Taking samples

 Powders:  Mix thoroughly  Use sterile spoon, ladle, dipper  Sub sample if necessary

Swabs

 Often -ve so take care!  Do  Use template  Target organism  Refrigerate after use  Don’t  Swab dirty surfaces  Swab freshly sanitised surfaces

ATP swabs

 Swab area - colour change indicates pass/fail  Simplest form will detect food traces  Useful as indicator of cleanliness  More expensive - will detect bacterial residues

10 10/10/2018

Rapid swabs

Storage and Transport

 Samples should be :  Transported  Stored  To inhibit changes in microbial numbers

Storage and Transport

 Ambient Foods  Keep in conditions as advised by manufacturer  Chilled Foods  Keep below 8°C  Hot samples  Cool to 8°C asap  use large sample container

11 10/10/2018

Use of Cool Boxes

 Equipment  Conform to BS 6672 and be rated “****”  Fitted with insulated lid  10% volume ice packs  ie 32 litre box will require 8 x 400g ice packs  Ice packs placed in freezer > 24 hrs prior to use  Packs placed at top and bottom of box  Allow air circulation  Cut down milk crate

Cool boxes

Diagram 1 - Preparation of cool box Section through Cool Box showing and position of ice packs

Block of Polystyrene Insulation added to inside of Lid of Sample Cool box Retaining System (or Cut Down Milk Crate) 400g ice packs Insert in placed above and Cool Box below the sample retaining system (milk crate)

Cool boxes

Diagram 2 - Plan of Cool Box showing position of Food Samples and Logger

6 1 3 5

Logger 4 2 7

12 10/10/2018

Use of Cool Boxes

 Security strap  Data logger / simulant sample  Use different cool boxes for hot and cold foods  Never mix potable and non-potable water samples in same box  Avoid unnecessary opening/closing  Don’t allow food to come into contact with ice blocks

Recommended Sample Information

 Name, address and  Conditions of storage at Authority of Officer point of sampling  Sample number  Other storage info  Date, time, place of sampling  Method of sampling  Description of sample  Conditions of storage  Reason for sampling since sampling  Name of owner,  Clinical details manufacturer etc  Process date  Country of origin

Report to FBO

 Clear language  Significance of result  Positive or negative  Relate to HACCP

13 10/10/2018

Summary

Why sample foods?

Legal framework

Approach to sampling

Sampling technique

Dr Andy Bowles Specialist Food Law Solicitor

[email protected]