Overview
ISO 11290-1:2017 - Microbiology of the food chain: Horizontal method for the detection and enumeration of Listeria monocytogenes and of Listeria spp. - Part 1: Detection method - is an international standard that specifies a horizontal laboratory method for detecting L. monocytogenes and Listeria spp. in food, animal feed and environmental samples from food production and handling areas. This second edition (2017) updates the 1996 version, expands scope to include Listeria spp., and provides harmonized requirements for selective enrichment, isolation and confirmation.
Key technical topics and requirements
- Scope and applicability: Detection of L. monocytogenes and other Listeria species in products intended for human or animal consumption and environmental monitoring in food-related areas.
- Principle: Uses selective enrichment to recover stressed or low-level Listeria organisms. The method comprises four successive stages (flowchart in Annex A): primary enrichment, secondary enrichment, plating onto selective agars, and confirmation.
- Enrichment media:
- Primary enrichment in half‑Fraser broth (reduced selective agents) - incubation modified to 25 h ± 1 h.
- Secondary enrichment in Fraser broth (full selective agents) - incubation 24 h ± 2 h.
- Isolation and identification: Plating onto selective Listeria agars (e.g., Ottaviani and Agosti agar / ALOA) and use of confirmatory tests as described in Clause 9 and Annexes E and D.
- Confirmation and interpretation: Selection of suspect colonies and biochemical/physiological confirmation procedures; optional microscopic, CAMP and catalase tests in specified situations.
- Performance and quality: Includes sections on method validation, sensitivity, specificity and level of detection (LOD), plus requirements for sampling, sample preparation, equipment, quality assurance and test reporting.
- Safety: Recommends testing in properly equipped laboratories (biosafety level 2), with warnings about risks to pregnant staff and immunocompromised persons.
Practical applications and users
ISO 11290-1:2017 is intended for:
- Food and feed microbiology laboratories performing Listeria monocytogenes detection and environmental monitoring.
- Food manufacturers, quality control and assurance teams implementing routine testing and supplier verification.
- Public health and regulatory laboratories conducting surveillance and compliance testing.
- Contract testing labs offering food safety analysis services.
Practical uses include routine screening of finished products, raw materials, processing environments, and verification of sanitation controls to support food safety management systems (HACCP, GFSI).
Related standards
Normative references and complementary methods:
- ISO 6887 (sample preparation)
- ISO 7218 (general microbiological requirements)
- ISO 11133 (culture media preparation and quality)
Keywords: ISO 11290-1:2017, Listeria monocytogenes detection, Listeria spp., horizontal method, food microbiology, half‑Fraser broth, Fraser broth, selective enrichment, food safety testing.
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