SIST EN ISO 11290-1:2017/A1:2026

• Status: Published
• Public Enquiry End Date: 30-Jul-2025
• Publication Date: 19-Aug-2026
• 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
• Completion Date: 20-Aug-2026
• Ref Project: EN ISO 11290-1:2017/A1:2026 - Microbiology of the food chain - Horizontal method for the detection and enumeration of Listeria monocytogenes and of Listeria spp. - Part 1: Detection 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 1:2017/Amd 1:2026)

• Amends: SIST EN 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 (ISO 11290-1:2017)
• Effective Date: 01-Sep-2026

SIST EN ISO 11290-1:2017/A1:2026 is the Slovenian adoption of EN ISO 11290-1:2017/A1:2026, an amendment to the horizontal method for detecting Listeria monocytogenes and Listeria spp. in the food chain. It updates how samples are handled before analysis and changes the control strain used for performance testing of culture media and reagents, so it is mainly relevant to food microbiology laboratories and quality assurance work.

What does SIST EN ISO 11290-1:2017/A1:2026 specify?

SIST EN ISO 11290-1:2017/A1:2026 specifies amendments to Part 1 of the ISO 11290 series, which is the detection method for Listeria monocytogenes and Listeria spp.. The document keeps the scope of the base standard and updates the text where sample storage and media verification are addressed.

Clause / part	What it covers
Clause 7	Sampling, transportation and storage of samples
9.5.2.5.2 and 9.5.2.6	Updated control strain for media and reagent performance checks
Annex B, Clause B.5, Tables B.1 and B.2	Performance testing for culture media and reagents

In practice, this amendment tells laboratories how to handle stored samples before analysis and how to verify that media and reagents still perform as expected.

What are the key requirements of SIST EN ISO 11290-1:2017/A1:2026?

Sampling, transport and storage

SIST EN ISO 11290-1:2017/A1:2026 replaces Clause 7 with instructions on sampling, transport and storage. Sampling itself is not part of the method, so users are directed to the product-specific sampling standard, or to an agreement between the parties if no product standard exists.

The amendment stresses that the laboratory should receive a representative sample that has not been damaged or altered during transport or storage. If the storage conditions from ISO 7218 cannot be used, another condition may be applied only when the lab can show that it does not change the contamination level, and the report must justify the choice.

Updated control strain

SIST EN ISO 11290-1:2017/A1:2026 replaces Listeria monocytogenes WDCM 00109 with Listeria monocytogenes WDCM 00231 in 9.5.2.5.2 and 9.5.2.6. This matters because the laboratory must use the revised strain when checking the relevant culture media and reagent performance.

Performance testing of media and reagents

SIST EN ISO 11290-1:2017/A1:2026 revises Annex B, Clause B.5, and links the testing approach to ISO 11133. The amendment says to follow ISO 11133 for the definitions of productivity, specificity and selectivity, and to use its procedures as the general basis for verification.

Table B.1 covers quality assurance of enrichment and isolation media, while Table B.2 covers confirmation tests for media and reagents. For the second isolation medium, the amendment points users to the manufacturer’s specifications. In practice, this means the laboratory must verify both growth-supporting media and confirmation reagents before routine use.

Test organisms and verification reactions

SIST EN ISO 11290-1:2017/A1:2026 keeps the detailed reaction checks in Annex B for media and confirmation work, including growth, inhibition, motility, Gram reaction, haemolysis, CAMP reaction, carbohydrate utilization and Voges-Proskauer testing. These checks help confirm that the system distinguishes target Listeria from look-alike organisms.

Sample storage before analysis

SIST EN ISO 11290-1:2017/A1:2026 adds explicit support for sample storage before analysis. If alternative storage conditions are used, they must be justified in the test report. For users, that means storage decisions become part of documented laboratory control, not just a practical convenience.

What terms does SIST EN ISO 11290-1:2017/A1:2026 define?

• Listeria monocytogenes - the target species the detection method is designed to find.
• Listeria spp. - the broader group of Listeria species covered by the method.
• Control strain - a reference strain used to check that a medium or reagent gives the expected reaction.
• Productivity - the ability of a medium to support growth of the intended organism.
• Selectivity - the ability of a medium to suppress unwanted organisms while allowing the target to grow.
• Specificity - the ability of a test or medium to react correctly with the intended organism and not with similar non-target organisms.
• WDCM - the strain-number reference used in the tables to identify the culture collection strains.

Who uses SIST EN ISO 11290-1:2017/A1:2026?

SIST EN ISO 11290-1:2017/A1:2026 is used by food microbiology laboratories, quality managers, and technical staff who test food, milk, animal feed and surfaces for Listeria. It is also relevant to suppliers of culture media and reagents, because Annex B sets out the performance checks those products should pass before use in the method.

What changed in SIST EN ISO 11290-1:2017/A1:2026 from the previous edition?

Compared with EN ISO 11290-1:2017, Amendment 1 adds storage of samples before analysis and changes the control strain used for performance testing of culture media and reagents. It also revises the relevant sample-handling text in Clause 7 and the media verification text in Annex B.

Which standards are used with SIST EN ISO 11290-1:2017/A1:2026?

• ISO 7218 - provides conditions for sample storage before analysis.
• ISO 11133 - gives the general approach and definitions for performance testing of culture media.
• ISO/TS 17728 - gives recommended sampling techniques for food and animal feed.
• ISO 707 | IDF 50 - gives sampling guidance for milk and milk products.
• ISO 18593 - gives sampling guidance for surfaces.
• ISO 20976-1 - covers challenge tests for shelf-life studies, which are outside this amendment’s scope.

What does the SIST EN ISO 11290-1:2017/A1:2026 document contain?

The document contains the amended wording for Clause 7, the revised strain references in 9.5.2.5.2 and 9.5.2.6, and the updated Annex B performance-testing text. Annex B includes tabulated checks for media and reagents, with the required test reactions, incubation conditions and reference strains used for verification.

It also adds bibliography entries for ISO 707 | IDF 50, ISO 20976-1 and a streak-plate protocol reference. These additions support laboratory sampling, storage decisions and routine quality control of the detection method.

SLOVENSKI STANDARD
01-september-2026
Mikrobiologija v prehranski verigi - Horizontalna metoda za ugotavljanje
prisotnosti in števila Listeria monocytogenes in Listeria spp. - 1. del: Metoda za
ugotavljanje prisotnosti - Dopolnilo A1: Vključitev shranjevanja vzorcev pred
analizo in sprememb kontrolnega seva za preskušanje učinkovitosti gojišč in
reagentov (ISO 11290 1:2017/Amd 1:2026)
Microbiology of the food chain - Horizontal method for the detection and enumeration of
Listeria monocytogenes and of Listeria spp. - Part 1: Detection 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 1:2017/Amd 1:2026)
Mikrobiologie der Lebensmittelkette - Horizontales Verfahren für den Nachweis und die
Zählung von Listeria monocytogenes und von Listeria spp. - Teil 1: Nachweisverfahren -
Änderung 1: Aufnahme der Lagerung der Proben vor der Analyse und Änderungen des
Kontrollstamms für die Leistungsprüfung von Kulturmedien und Reagenzien (ISO 11290
1:2017/Amd 1:2026)
Microbiologie de la chaîne alimentaire - Méthode horizontale pour la recherche et le
dénombrement de Listeria monocytogenes et de Listeria spp. - Partie 1: Méthode de
recherche - Amendement 1: Inclusion du stockage des échantillons avant analyse et
modifications de la souche témoin pour les essais de performance des milieux de culture
et des réactifs (ISO 11290 1:2017/Amd 1:2026)
Ta slovenski standard je istoveten z: EN ISO 11290-1:2017/A1:2026
ICS:
07.100.30 Mikrobiologija živil Food microbiology
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 11290-1:2017/A1
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2026
EUROPÄISCHE NORM
ICS 07.100.30
English Version
Microbiology of the food chain - Horizontal method for the
detection and enumeration of Listeria monocytogenes and
of Listeria spp. - Part 1: Detection 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 1:2017/Amd
1:2026)
Microbiologie de la chaîne alimentaire - Méthode Mikrobiologie der Lebensmittelkette - Horizontales
horizontale pour la recherche et le dénombrement de Verfahren für den Nachweis und die Zählung von
Listeria monocytogenes et de Listeria spp. - Partie 1: Listeria monocytogenes und von Listeria spp. - Teil 1:
Méthode de recherche - Amendement 1: Inclusion du Nachweisverfahren - Änderung 1: Aufnahme der
stockage des échantillons avant analyse et Lagerung der Proben vor der Analyse und Änderungen
modifications de la souche témoin pour les essais de des Kontrollstamms für die Leistungsprüfung von
performance des milieux de culture et des réactifs (ISO Kulturmedien und Reagenzien (ISO 11290
11290 1:2017/Amd 1:2026) 1:2017/Amd 1:2026)
This amendment A1 modifies the European Standard EN ISO 11290-1:2017; it was approved by CEN on 1 July 2026.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for inclusion of
this amendment into the relevant national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This amendment exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11290-1:2017/A1:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 11290-1:2017/A1:2026) has been prepared by Technical Committee ISO/TC 34
"Food products" in collaboration with Technical Committee CEN/TC 463 “Microbiology of the food
chain” the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by January 2027, and conflicting national standards shall
be withdrawn at the latest by January 2027.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 11290-1:2017/Amd 1:2026 has been approved by CEN as EN ISO 11290-
1:2017/A1:2026 without any modification.

International
Standard
ISO 11290-1
Second edition
Microbiology of the food chain —
2017-05
Horizontal method for the detection
and enumeration of Listeria
AMENDMENT 1
monocytogenes and of Listeria
2026-07
spp. —
Part 1:
Detection 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
Microbiologie de la chaîne alimentaire — Méthode
horizontale pour la recherche et le dénombrement de Listeria
monocytogenes et de Listeria spp. —
Partie 1: Méthode de recherche
AMENDEMENT 1: Inclusion du stockage des échantillons avant
l'analyse et modifications de la souche témoin pour les essais de
performance des milieux de culture et des réactifs
Reference number
ISO 11290-1:2017/Amd.1:2026(en) © ISO 2026

ISO 11290-1:2017/Amd.1:2026(en)
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO 11290-1:2017/Amd.1:2026(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,
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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 document 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 of 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 www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 9,
Microbiology, in collaboration with the European Committee for Standardization (CEN) Technical Committee
CEN/TC 463, Microbiology of the food chain, in accordance with the Agreement on technical cooperation
between ISO and CEN (Vienna Agreement).
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
ISO 11290-1:2017/Amd.1:2026(en)
Microbiology of the food chain — Horizontal method for the
detection and enumeration of Listeria monocytogenes and of
Listeria spp. —
Part 1:
Detection 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. Follow the specific International Standard
dealing with the product concerned. If there is no specific International Standard dealing with the sampling
of the product concerned, it is recommended that the parties concerned come to an agreement on this
subject. Recommended sampling techniques are given in the following documents:
[3]
— ISO/TS 17728 for food and animal feed;
[31]
— ISO 707 for milk and milk products;
[2]
— ISO 18593 for surfaces (see also Reference [24]).
It is important that the laboratory receives a sample which is representative of the product under
consideration. The sample should not have been damaged or changed during transport or storage.
[32]
NOTE 1 Shelf-life studies are not in the scope of this document but of ISO 20976-1 .
For storage conditions before analysis, see ISO 7218.
If ISO 7218 conditions cannot be applied, other storage conditions may be used provided it can be
demonstrated that the alternative conditions do not affect the contamination levels of Listeria spp./Listeria
monocytogenes. These conditions should be detailed and justified in the test report.
NOTE 2 Supporting data for storage of food samples before detection of Listeria monocytogenes or Listeria spp. are
available from: https:// standards .iso .org/ iso/ 11290/ -2/ ed -2/ en/ amd/ 1.

9.5.2.5.2 and 9.5.2.6
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 monocytogenes
WDCM 00231 are available at: https:// standards .iso .org/ iso/ 11290/ -1/ ed -2/ en/ amd/ 1.

ISO 11290-1:2017/Amd.1:2026(en)

Clause B.5
Replace the text with the following:
B.5  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 media for the enrichment and isolation. Table B.2 provides the
performance testing for the quality assurance of the culture media and reagents for the confirmation tests.
For the second isolation medium, use performance testing according to the manufacturer’s specifications.
NOTE For productivity testing, in the case of detection of Listeria spp., it can be informative to add another control
strain (from another Listeria species sensu stricto).
Table B.1 — Performance testing for the quality assurance of the culture media for the enrichment
and isolation
Media Function Incubation Control strains WDCM Reference Method of Criteria and
a
numbers media control characteristic
c
reactions
Listeria
b
monocytogenes 00021
Good growth
serovar 4b
with at least two
00012 or
d
+ Escherichia coli
streaks with
confluent growth
+ Enterococcus 00009 or
of blue green col-
d
faecalis 00087
onies with opaque
Productivity — Qualitative halo on Agar
Listeria
Listeria according
monocytogenes
e
Half- (25 ± 1) h/
to Ottaviani and
serovars
f
Fraser (30 ± 1) °C
Agosti
1/2a, 3a
in a three-phase
00012 or
d
or a four-phase
+ Escherichia coli
h
streaking pattern
+ Enterococcus 00009 or
d
faecalis 00087
00012 or < 10 colonies
d
Escheric
...