SIST EN ISO 11290-2:2017/A1:2026

• Status: Not Published
• Public Enquiry End Date: 30-Jul-2025
• ICS: 07.100.30 - Food microbiology
• Technical Committee: KŽP - Agricultural food products
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 30-Jul-2026
• Due Date: 04-Oct-2026
• Ref Project: EN ISO 11290-2:2017/A1:2026 - Microbiology of the food chain - Horizontal method for the detection and enumeration of Listeria monocytogenes and of Listeria spp. - Part 2: Enumeration method - Amendment 1: Inclusion of storage of the samples before analysis and changes in the control strain for performance testing of culture media and reagents (ISO 11290-2:2017/Amd 1:2026)

• Amends: SIST EN ISO 11290-2:2017 - Microbiology of the food chain - Horizontal method for the detection and enumeration of Listeria monocytogenes and of Listeria spp. - Part 2: Enumeration method (ISO 11290-2:2017)
• Effective Date: 01-Sep-2026

Overview

SIST EN ISO 11290-2:2017/A1:2026 is an amendment to the widely recognized international standard for food microbiology testing, specifically focusing on the enumeration of Listeria monocytogenes and Listeria spp. in the food chain. This amendment introduces two essential updates:

• The inclusion of storage conditions for samples prior to analysis
• Changes to the control strain used in performance testing of culture media and reagents

By addressing sample storage and updating reference strains for laboratory quality assurance, the amendment further strengthens reliability and harmonization in Listeria testing, supporting food safety management systems and regulatory compliance.

Key Topics

The amendment covers several critical areas relevant to laboratories and food safety professionals:

• Sample Storage Before Analysis

  • Defines conditions for storing food and environmental samples prior to microbiological testing
  • Recommends refrigeration of perishable samples at 2°C to 8°C, with guidance when immediate analysis is not possible
  • Requires reporting of any deviations or extended storage periods in laboratory test reports

• Reference Methods for Different Sample Types

  • Aligns storage protocols with other international standards, such as ISO 7218 for nonperishable products and frozen foods
  • Directs users to ISO/TS 17728 and ISO 18593 for food, feed, and environmental sampling procedures

• Control Strain Update in Culture Media Performance Testing

  • Replaces Listeria monocytogenes WDCM 00109 with Listeria monocytogenes WDCM 00231 as the standard control strain
  • Ensures consistency and current best practices in quality assurance of culture media and reagents

• Performance Testing Protocols

  • Reiterates the importance of productivity, specificity, and selectivity checks as outlined in ISO 11133
  • Details positive and negative controls necessary for verifying media and reagent performance

Applications

SIST EN ISO 11290-2:2017/A1:2026 is an essential tool for:

• Food testing laboratories: Ensures that detection and enumeration of Listeria monocytogenes and other Listeria species are accurate and reliable, improving overall laboratory quality management.
• Food manufacturers and processors: Assists companies in meeting food safety standards by providing validated processes for sample storage and testing, which is critical for regulatory compliance and risk assessment.
• Regulatory agencies and auditors: Supports effective monitoring and verification of food safety controls across the supply chain, enabling harmonized application of Listeria testing methods.
• Accreditation bodies: Offers updated guidance for laboratory accreditation assessments, focusing on both technical procedures and documentation of storage/handling protocols.

Related Standards

This amendment should be used in conjunction with related international standards that further define best practices in microbiological testing and quality assurance:

• ISO 11290-2:2017 – Microbiology of the food chain - Enumeration method for Listeria monocytogenes and Listeria spp.
• ISO 7218 – General requirements and guidance for microbiological examinations
• ISO/TS 17728 – Sampling techniques for microbiological analysis in food and feed
• ISO 18593 – Sampling procedures for environmental monitoring in the food industry
• ISO 11133 – Preparation, production, storage, and performance testing of culture media

By integrating the guidance of SIST EN ISO 11290-2:2017/A1:2026 with these standards, organizations can ensure consistent, defensible results in Listeria testing and broader food safety initiatives.

Keywords: Listeria monocytogenes enumeration, food chain microbiology, food safety testing, sample storage for microbiology, culture media performance, reference strains for Listeria, ISO 11290-2 amendment, laboratory quality assurance, food industry standards.

SLOVENSKI STANDARD
SIST EN ISO 11290-2:2017/oprA1:2025
01-julij-2025
Mikrobiologija v prehranski verigi - Horizontalna metoda za ugotavljanje
prisotnosti in števila Listeria monocytogenes in Listeria spp. - 2. del: Metoda štetja
- Dopolnilo A1: Vključitev shranjevanja vzorcev pred analizo in sprememb
kontrolnega seva za preskušanje učinkovitosti gojišč in reagentov (ISO 11290-
2:2017/DAmd1:2025)
Microbiology of the food chain - Horizontal method for the detection and enumeration of
Listeria monocytogenes and of Listeria spp. - Part 2: Enumeration method - Amendment
1: Inclusion of storage of the samples before analysis and changes in the control strain
for performance testing of culture media and reagents (ISO 11290-2:2017/DAmd1:2025)
Mikrobiologie der Lebensmittelkette - Horizontales Verfahren für den Nachweis und die
Zählung von Listeria monocytogenes und von Listeria spp. - Teil 2: Zählverfahren -
Änderung 1: Aufnahme der Lagerung der Proben vor der Analyse und Änderungen des
Kontrollstamms für die Leistungsprüfung von Kulturmedien und Reagenzien (ISO 11290
2:2017/DAmd1:2025)
Microbiologie de la chaîne alimentaire - Méthode horizontale pour la recherche et le
dénombrement de Listeria monocytogenes et de Listeria spp. - Partie 2: Méthode de
dénombrement - Amendement 1: Inclusion du stockage des échantillons avant l'analyse
et les modifications dans la souche témoin pour les essais de performance des milieux
de culture et des réactifs (ISO 11290-2:2017/DAmd1:2025)
Ta slovenski standard je istoveten z: EN ISO 11290-2:2017/prA1:2025
ICS:
07.100.30 Mikrobiologija živil Food microbiology
SIST EN ISO 11290-2:2017/oprA1:2025 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

SIST EN ISO 11290-2:2017/oprA1:2025

SIST EN ISO 11290-2:2017/oprA1:2025
DRAFT
Amendment
ISO 11290-2:2017/
DAM 1
ISO/TC 34/SC 9
Microbiology of the food chain —
Secretariat: AFNOR
Horizontal method for the detection
and enumeration of Listeria
Voting begins on:
2025-05-19
monocytogenes and of Listeria
Voting terminates on:
spp. —
2025-08-11
Part 2:
Enumeration method
AMENDMENT 1: Inclusion of storage
of the samples before analysis and
changes in the control strain for
performance testing of culture media
and reagents
ICS: 07.100.30
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS.
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Reference number
ISO 11290-2:2017/DAM 1:2025(en)

SIST EN ISO 11290-2:2017/oprA1:2025
DRAFT
ISO 11290-2:2017/DAM 1:2025(en)
Amendment
ISO 11290-2:2017/
DAM 1
ISO/TC 34/SC 9
Microbiology of the food chain —
Secretariat: AFNOR
Horizontal method for the
detection and enumeration of
Voting begins on:
Listeria monocytogenes and of
Voting terminates on:
Listeria spp. —
Part 2:
Enumeration method
AMENDMENT 1: Inclusion of storage
of the samples before analysis and
changes in the control strain for
performance testing of culture media
and reagents
ICS: 07.100.30
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2025
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
or ISO’s member body in the country of the requester.
NATIONAL REGULATIONS.
ISO copyright office
RECIPIENTS OF THIS DRAFT ARE INVITED
CP 401 • Ch. de Blandonnet 8
TO SUBMIT, WITH THEIR COMMENTS,
CH-1214 Vernier, Geneva
NOTIFICATION OF ANY RELEVANT PATENT
Phone: [phone]
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ISO 11290-2:2017/DAM 1:2025(en)

ii
SIST EN ISO 11290-2:2017/oprA1:2025
ISO 11290-2:2017/DAM 1:2025(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types
of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the World
Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL:
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 9,
Microbiology.
A list of all parts in the ISO 11290 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iii
SIST EN ISO 11290-2:2017/oprA1:2025

SIST EN ISO 11290-2:2017/oprA1:2025
ISO 11290-2:2017/DAM 1:2025(en)
Microbiology of the food chain — Horizontal method for the
detection and enumeration of Listeria monocytogenes and of
Listeria spp. —
Part 2:
Enumeration method
AMENDMENT 1: Inclusion of storage of the samples before
analysis and changes in the control strain for performance testing
of culture media and reagents
Clause 7
Replace the text with the following:
7.  Sampling, transportation and storage of samples
Sampling is not part of the method specified in this document. If there is no specific International Standard
dealing with sampling of the product concerned, it is recommended that the parties concerned come to an
agreement on this subject. For food and feed samples, refer to ISO/TS 17728. For environmental samples,
use ISO 18593 and see Reference [23].
It is important that the laboratory receives a sample which is truly representative and has not been damaged
or changed during transport or storage (see ISO 7218).
For nonperishable or low-moisture foods samples, as well as frozen or deep-frozen products, refer to
ISO 7218 Standard for storage conditions before analysis.
Before analysis, store chilled perishable foods samples refrigerated at 2 °C to 8 °C. Examine them immediately
upon receipt if possible, and if not possible, within a delay less than 8 h.
In case of late arrival on the working day, this duration may be extended up to 24 h after receipt, and the
delay should be reported in the test report.
In case of refrigeration storage temperature between 1 °C and 5 °C, this duration may be extended up to 24 h
after receipt, and the storage conditions should be reported in the test report.
If these conditions can’t be respected, use other storage conditions in which previously it has been
demonstrated that Listeria spp./Listeria monocytogenes contamination level won’t be modified or agreed
between parties concerned. These conditions should be detailed and justified in the test report.
9.4.2.5.2 and 9.4.2.6
Replace all instances of Listeria monocytogenes WDCM 00109 with Listeria monocytogenes WDCM 00231.

Add the following note after the last paragraph:
NOTE Supporting data for the replacement of Listeria monocytogenes WDCM 00109 by Listeria moncytogenes
WDCM 00231 are available at: https:// standards .iso .org/ iso/ 11290/ -2/ ed -2/ en/ amd/ 1

SIST EN ISO 11290-2:2017/oprA1:2025
ISO 11290-2:2017/DAM 1:2025(en)
Clause B.2.8
Replace the text with the following:
B.2.8 Performance testing for the quality assurance of the culture media and reagents
The definition of productivity, specificity and selectivity are specified in ISO 11133. In general, follow the
procedures for performance testing described in ISO 11133. Table B.1 provides the performance testing
for the quality assurance of the culture medium for the enumeration. Table B.2 provides the performance
testing for the quality assurance of the culture mediaand reagents for the confirmation tests.
NOTE For productivity testing, in the case of enumeration of Listeria spp., it could be informative to add another
control strain (from another Listeria spp.).
Table B.1 — Performance testing for the quality assurance of the culture medium for the
enumeration
a
Medium Function Incubation Control strains WDCM Reference Method of Criteria and
a
or rea- numbers media control characteristic
c
gent reactions
Listeria
b
monocytogenes 00021
P ≥ 0,5,
R
serovar 4b
Quantita- blue green colo-
f
Producti
...