Overview
EN ISO 21872-1:2017/A1:2023 is an amendment to the international/CEN standard for the microbiology of the food chain. It covers the horizontal method for the detection of potentially enteropathogenic Vibrio parahaemolyticus, Vibrio cholerae and Vibrio vulnificus and adds explicit requirements for performance testing of culture media and reagents. The amendment aligns media quality assurance with ISO 11133 and supplies additional guidance in Annex B (Clause B.12).
Key Topics
- Amendment focus: Inclusion of performance testing procedures for culture media and reagents to support reliable detection of Vibrio spp.
- Normative linkage: Performance testing is to be carried out in accordance with ISO 11133 and the new Clause B.12 in this amendment.
- Annex B additions: Clause B.12 defines the approach to performance testing and references two new tables (Table B.1 and Table B.2) that guide quality assurance.
- Performance tables:
- Table B.1 details performance testing for selective and non-selective culture media (examples in the tables include TCBS, saline peptone water (ASPW) and saline nutrient agar (SNA)), listing control strains and qualitative productivity/selectivity criteria.
- Table B.2 covers confirmation media and reagent performance (examples include arginine dihydrolase, indole, oxidase, L-lysine decarboxylase, halotolerance/NaCl tests and β-galactosidase), with suggested control strains and expected positive/negative reactions.
- Control strains and traceability: The amendment references World Data Centre for Microorganisms (WDCM) strain numbers and notes national restrictions that may apply to use, storage or transport of some strains (for example V. cholerae).
Applications
- Food microbiology laboratories validating or accrediting Vibrio detection workflows.
- Quality assurance teams performing routine performance testing of culture media and reagent lots.
- Public health and regulatory testing where standardized detection methods and media validation reduce false negatives and improve inter-laboratory comparability.
- Aquaculture and seafood testing to support safe supply chain monitoring.
Practical benefits include clearer acceptance criteria for media, improved reproducibility of Vibrio detection, and harmonised procedures for media performance testing when used together with ISO 11133.
Related Standards
- ISO 21872-1:2017 (original Part 1 standard for Vibrio detection)
- ISO 11133 (performance testing of culture media and reagents)
- CEN/TC 463 and ISO/TC 34 (technical committees responsible for microbiology of the food chain)
For implementation, laboratories should apply the procedures in ISO 11133 and follow Clause B.12 and the annex tables to ensure media and reagent performance meets the criteria specified by EN ISO 21872-1:2017/A1:2023.
