ISO 15213-2:2023 PDF

Overview

ISO 15213-2:2023 - Microbiology of the food chain - Horizontal method for the detection and enumeration of Clostridium spp. - Part 2 specifies a colony-count technique for enumeration of Clostridium perfringens. The standard applies across the food chain: products for human consumption, animal feed, environmental samples from food/feed production and handling, and primary production stage samples. It updates and replaces ISO 7937:2004 and has been validated in interlaboratory studies for multiple food categories.

Relevant keywords: ISO 15213-2:2023, Clostridium perfringens, colony-count technique, microbiology of the food chain, enumeration, food safety.

Key topics and technical requirements

• Principle: Enumeration by plating on a selective medium under obligate anaerobic conditions followed by colony counting and confirmation.
• Sample types: Ready-to-eat / ready-to-reheat meat, eggs and egg products, processed fruits and vegetables, infant formula/cereals, multi-component foods; also validated for pet food, animal feed and production environment samples.
• Detection limits: Technique suited for samples yielding at least 10 colonies per plate (≈ >10 cfu/ml for liquids or >100 cfu/g for solids).
• Culture media & reagents: Use of tryptose sulfite cycloserine (TSC) agar (renamed from sulfite-cycloserine agar without formulation change); performance criteria for media included in Annex B.
• Heat treatment: Optional heat treatment (historically 10 min at 80 °C) to select for spores or reduce background flora - now optional depending on sample/background flora.
• Enumeration & confirmation: Enumeration, selection of typical colonies and confirmation procedures (acid phosphatase test; SIM agar test) described. Optional molecular differentiation between pathogenic and non-pathogenic C. perfringens is provided (Annex D).
• Validation: Contains interlaboratory validation data and performance characteristics (Clause 11; Annex C).
• Safety & quality: Specifies laboratory competence, biosafety precautions, quality assurance and test reporting requirements.

Applications and users

• Who uses it: Food and feed microbiology laboratories, QA/QC teams, regulatory agencies, contract testing labs, researchers, and environmental monitoring units in production facilities.
• Practical uses:
  • Routine monitoring of C. perfringens in finished foods and feeds
  • Supplier verification and HACCP verification activities
  • Outbreak investigation and epidemiological support (when combined with molecular typing)
  • Environmental screening in processing plants
  • Method validation and media performance testing in lab accreditation

Related standards

• ISO 15213-1 (sulfite‑reducing Clostridium spp. enumeration)
• ISO/TS 15213-3 (detection of C. perfringens)
• ISO 7218, ISO 6887 (sample prep and general microbiological exam)
• ISO 11133 (culture media production and testing)
• ISO 14189 (confirmation methods reference)
• ISO 19036 (estimation of measurement uncertainty)

This standard is essential for laboratories seeking a validated, horizontal method for reliable quantification of C. perfringens in diverse food-chain matrices.