Code of practice for microbiology laboratories handling food, drink and associated samples

Transcription

1 Guideline no. 9 Code of practice for microbiology laboratories handling food, drink and associated samples 4th edition Suzanne Jordan 2013 ISBN: Station Road, Chipping Campden, Gloucestershire, GL55 6LD, UK Tel: +44(0) Fax: +44(0) Information emanating from this company is given after the exercise of all reasonable care and skill in its compilation, preparation and issue, but is provided without liability in its application and use. Legislation changes frequently. It is essential to confirm that legislation cited in this publication and current at the time of printing, is still in force before acting upon it. The information contained in this publication must not be reproduced without permission from the Publications Manager.

2 CONTENTS Page no. 1 INTRODUCTION 1 2. LABORATORY DESIGN, SAFETY, HYGIENE AND SECURITY Laboratory facility Personnel Personal hygiene and safety Microbiological practices Control of substances hazardous to health (COSHH) Sending cultures by post Laboratory security 8 3. LABORATORY MANAGEMENT Records General requirements Electronic storage of data Traceability Laboratory quality assurance Laboratory accreditation Accreditation requirements The accreditation procedure Appraisal of laboratory performance Laboratory information management systems (LIMS) Introduction of new methods/method modifications in the laboratory External independent validation In-house evaluation Planning an in-house evaluation EQUIPMENT Autoclaves Automatic pipetters Automatic plate pourers Balances Centrifuges Conductivity meters Fume cupboards Glassware and other containers Gravimetric diluters 25 - iii -

3 4.10 Hotplates/Hotplate Stirrers Incubators Laminar airflow cabinets Media dispensers Media preparators Membrane filter units Microscopes Modified atmosphere generating systems ph meters Rapid/assisted methods ATP luminescence test methods Automated identification systems Automated plate counters Conductance/impedance equipment ELISA plate washers ELISA plate readers/spectrophotometers Spiral platers Thermal cyclers Others Refrigerators and freezers Safety cabinets Steamers Sterilising ovens Stomachers, pulsifiers and homogenisers Temperature monitoring devices UV lamps Water baths Water purification equipment Working temperature devices MEDIA PREPARATION Introduction Dehydrated media, supplements and chemicals Preparation and sterilisation of apparatus Water quality Reconstitution of media Weighing out dehydrated media and chemicals Mixing of powders with water Dissolving media prior to sterilisation Liquid media Solid media 45 - iv -

4 5.6 ph measurement Media dispensing Sterilisation of media Tempering of media Media supplements Storage of prepared media Precautions using stored poured plates Re-melting prepared bottled media Pouring of plates Drying of plates Media efficacy checks Reference cultures Trouble shooting guide Records PROCEDURES Sample storage and handling Sample testing procedure Preparation of the test sample Test portion and initial suspension Mixing samples Liquid samples Other samples Dilution Inoculation of solid media Pour plates Spread plates Sampling by filtration and incubation on a nutrient support Membranes Filtration procedure Diluent and media controls Streak (pre poured) plates MPN techniques Heat shock technique Incubation Colony purification Confirmation techniques 67 - v -

5 7. RESULTS Counting, calculation and expression of results Most probable number methods Records of results Reporting of results Non-conforming results 77 REFERENCES 78 APPENDIX 1 81 Table 1: Examples of equipment quality monitoring checks 82 Table 2: Examples of rapid/assisted method equipment and quality monitoring checks 87 APPENDIX 2 89 Microscopy 90 APPENDIX Example records: Table 1: An example of sample test record page for the microbiology laboratory 102 Table 2: An example of a record card for a medium prepared from a commercially available dehydrated powder vi -