Overview
EN ISO 6888-3:2003 (ISO 6888-3:2003) - Microbiology of food and animal feeding stuffs - Part 3 - defines a horizontal detection and enumeration method for coagulase-positive staphylococci using the most probable number (MPN) technique. The standard is intended for products intended for human consumption and animal feed, and for environmental samples from food production and handling areas. It is particularly recommended where staphylococci are expected to be stressed or present in low numbers (for example, dried products). Coagulase-positive organisms primarily include Staphylococcus aureus, but may also include S. intermedius and some strains of S. hyicus.
Key Topics
- Scope and applicability: Horizontal MPN-based method for detection/enumeration of coagulase-positive staphylococci in food, feed and production environments.
- Principle: Uses the MPN technique to detect low-level or stressed staphylococci populations; confirmation is based on coagulase reaction (with acknowledgement that weakly positive strains may require additional tests).
- Sample preparation: References standard procedures for preparing test samples, initial suspensions and decimal dilutions (see ISO 6887, ISO 8261).
- Procedure and interpretation: Contains separate subclauses for the detection method and the enumeration method, selection and interpretation of culture media/plates, expression of results, and reporting requirements.
- Quality and precision: Addresses precision, reporting, and the need for appropriate culture media quality control and laboratory practices.
- Harmonization: Part of the ISO 6888 series (Parts 1–3) and intended to be a harmonized, horizontal method where possible.
Applications
Who uses EN ISO 6888-3:2003:
- Food and feed microbiology laboratories performing routine testing
- Quality assurance and HACCP teams monitoring product safety
- Regulatory and public health laboratories assessing contamination
- Manufacturers of dried, low-moisture or processed foods where staphylococci may be stressed
Practical uses:
- Detection of low-level Staphylococcus aureus contamination in products and environments
- Supporting safety assessments, release testing and trend monitoring
- Complementing cultural methods (Parts 1 and 2) when organism counts are low or recovery is difficult
Related Standards
- ISO 6888-1:1999 - Baird‑Parker agar technique
- ISO 6888-2:1999 - Rabbit plasma fibrinogen agar technique
- ISO 6887 (all parts) - Preparation of test samples and dilutions
- ISO 7218 - General rules for microbiological examinations
- ISO 8261 - Milk and milk products - sample preparation guidance
- ISO/TS 11133 - Guidelines on culture media preparation and QA
This standard is essential for laboratories requiring a validated, harmonized MPN approach to detect and enumerate coagulase-positive staphylococci in low-count or stressed samples.
