Overview
EN ISO 11133:2014/A2:2020 is Amendment 2 to the international standard ISO 11133:2014, adopted by CEN in May 2020. The standard addresses the microbiology of food, animal feed and water with specific focus on the preparation, production, storage and performance testing of culture media. This amendment adds and references a new normative annex (Annex K) that defines control strains and procedures for performance testing of confirmation media and reagents used in food- and water-microbiology methods.
Key topics and requirements
- Addition of Annex K (normative): Annex K specifies control strains for performance testing of confirmation/characterization media, reagents, dyes, stains and related materials. It provides a table (Table K.1) listing suitable positive and negative control strains and their expected reactions.
- Qualitative performance testing: For confirmation media and reagents the inoculum is a subculture of an isolated colony; tests are qualitative. Use the shortest permissible incubation time from the relevant International Standard for positive controls and the longest permissible incubation time for negative controls.
- Reference strains: Strains in Table K.1 are preferentially selected from strains already cited in ISO 11133 or, when unavailable, from the World Data Centre for Microorganisms (WDCM) catalogue. Multiple strain options are provided; users can choose any cited strain for positive or negative reactions.
- Manufacturer and national requirements: Where commercial media/reagents are used, follow the manufacturer’s instructions. If an International Standard for a specific organism already specifies control strains (e.g., Campylobacter, Yersinia), these may be excluded from Table K.1; national regulations can require specific serovars.
- Cross-references: The amendment updates clause references to include Annex K among the sources of suitable test organisms for routine performance testing.
Applications and users
- Food, feed and water microbiology laboratories performing culture-based detection and confirmation tests.
- Manufacturers of culture media and diagnostic reagents who need validated performance testing protocols and control-strain guidance.
- Quality assurance and regulatory bodies responsible for method validation, accreditation and laboratory proficiency.
- Method developers and standards writers integrating confirmation media performance criteria into ISO/CEN microbiological standards.
Related standards and keywords
- Related ISO standards referenced for organism-specific procedures (e.g., ISO 10272, ISO 4831) may specify their own control strains.
- SEO keywords: EN ISO 11133:2014/A2:2020, ISO 11133, culture media, performance testing, confirmation media, microbiology of food, microbiology of water, control strains, WDCM.
