SIST EN ISO 11290-1:2017

Overview

EN ISO 11290-1:2017 (ISO 11290-1:2017) defines a horizontal, standardized detection method for Listeria monocytogenes and for Listeria spp. (including L. monocytogenes) in the food chain. The method is applicable to products intended for human consumption, animal feed, and environmental samples from food production and handling areas. Part 1 of the ISO 11290 series focuses on presence/absence detection; enumeration procedures are covered in the complementary part of the series.

Key topics and technical requirements

• Scope and applicability: routine testing of food, feed and environmental samples in food-related facilities.
• Principle of the method: two-stage selective enrichment followed by selective plating and confirmation.
  • Primary enrichment in half‑Fraser broth (reduced selective agents) - incubation updated to 25 h ± 1 h.
  • Secondary enrichment in Fraser broth (full selective strength) - incubation 24 h ± 2 h.
• Selective media and plating: isolation on selective agars (e.g., Agar Listeria according to Ottaviani and Agosti is referenced) with procedures for colony selection and confirmation.
• Confirmation procedures: biochemical and phenotypic tests for identification of L. monocytogenes and other Listeria species; some tests (microscopy, CAMP test, catalase) are optional depending on agar selectivity.
• Practical handling rules: refrigerated storage allowances-half‑Fraser and Fraser broths may be refrigerated before transfer/isolation for up to 72 h; incubated isolation plates may be refrigerated up to 2 days before reading.
• Performance characteristics: method validation, sensitivity, specificity and level of detection (LOD) are documented; interlaboratory study results and media compositions are included in annexes.

Applications and users

• Who uses it: food microbiology laboratories, quality assurance/control teams, regulatory authorities, contract testing labs, food/feed manufacturers performing environmental monitoring, HACCP verification, shelf‑life and product release testing, and outbreak/recall investigations.
• Why use it: provides a harmonized, ISO/CEN‑endorsed protocol ensuring reproducible detection of L. monocytogenes and Listeria spp., supports compliance with food safety regulations, and enables comparable results across laboratories.