EN ISO 21528-2:2017

Microbiology of the food chain - Horizontal method for the detection and enumeration of Enterobacteriaceae - Part 2: Colony-count technique (ISO 21528-2:2017, Corrected version 2018-06-01)

ISO 21528-2:2017 specifies a method for the enumeration of Enterobacteriaceae. It is applicable to
-      products intended for human consumption and the feeding of animals, and
-      environmental samples in the area of primary production, food production and food handling.
This technique is intended to be used when the number of colonies sought is expected to be more than 100 per millilitre or per gram of the test sample.
The most probable number (MPN) technique, as included in ISO 21528‑1, is generally used when the number sought is expected to be below 100 per millilitre or per gram of test sample.

Mikrobiologie der Lebensmittelkette - Horizontales Verfahren für den Nachweis und die Zählung von Enterobacteriaceae - Teil 2: Koloniezählverfahren (ISO 21528-2:2017, korrigierte Fassung 2018-06-01)

Microbiologie de la chaîne alimentaire - Méthode horizontale pour la recherche et le dénombrement des Enterobacteriaceae - Partie 2: Technique par comptage des colonies (ISO 21528-2:2017, Version corrigée 2018-06-01)

L'ISO 21528-2:2017 spécifie une méthode pour le dénombrement des Enterobacteriaceae. Elle est applicable:
-      aux produits destinés à l'alimentation humaine et animale, et
-      aux échantillons d'environnement pour la production au stade primaire, la production des aliments et la distribution des aliments.
Cette technique est destinée à être utilisée lorsque le nombre de colonies recherchées est supposé être supérieur à 100 par millilitre ou par gramme d'échantillon pour essai.
La technique du nombre le plus probable (NPP), incluse dans l'ISO 21528‑1, est généralement utilisée lorsque le nombre recherché est censé être inférieur à 100 par millilitre ou par gramme d'échantillon pour essai.

Mikrobiologija v prehranski verigi - Horizontalna metoda za ugotavljanje prisotnosti in števila enterobakterij - 2. del: Metoda štetja kolonij (ISO 21528-2:2017)

Ta del standarda EN ISO 21528 določa metodo za ugotavljanje števila enterobakterij brez predhodne obogatitve. Uporablja se za: – izdelke, namenjene za prehrano ljudi in krmo živali; in – okoljske vzorce na območju proizvodnje hrane in ravnanja s hrano. Ugotavljanje števila se izvaja s štetjem kolonij na trdem mediju po inkubaciji pri 37 °C (ali 30 °C).  Ta tehnika se priporoča, kadar se pričakuje več kot 100 kolonij na mililiter ali gram preskusnega vzorca.

General Information

• Status: Published
• Publication Date: 04-Jul-2017
• Withdrawal Date: 30-Jan-2018
• ICS: 07.100.30 - Food microbiology
• Technical Committee: CEN/TC 463 - Microbiology of the food chain
• Drafting Committee: CEN/TC 463 - Microbiology of the food chain
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 05-Jul-2017
• Due Date: 22-Nov-2015
• Completion Date: 05-Jul-2017
• Directive: 882/2004 - Regulation (EC) No 882/2004 of the European Parliament and of the Council of 29 April 2004 onofficial controls performed to ensure the verification of compliance with feed and food law, animal health and animal welfare rules
• Mandate: M/381 - Mandate for standardisation addressed to CEN in the field of Methods of analysis of foodstuffs concerning Food Hygiene
• Ref Project: SIST EN ISO 21528-2:2017 - Microbiology of the food chain - Horizontal method for the detection and enumeration of Enterobacteriaceae - Part 2: Colony-count technique (ISO 21528-2:2017)

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2017
Mikrobiologija v prehranski verigi - Horizontalna metoda za ugotavljanje
prisotnosti in števila enterobakterij - 2. del: Metoda štetja kolonij (ISO 21528-
2:2017)
Microbiology of the food chain - Horizontal method for the detection and enumeration of
Enterobacteriaceae - Part 2: Colony-count technique (ISO 21528-2:2017)
Mikrobiologie der Lebensmittelkette - Horizontales Verfahren für den Nachweis und die
Zählung von Enterobacteriaceae - Teil 2: Koloniezählverfahren (ISO 21528-2:2017)
Microbiologie de la chaîne alimentaire - Méthode horizontale pour la recherche et le
dénombrement des Enterobacteriaceae - Partie 2: Technique par comptage des colonies
(ISO 21528-2:2017)
Ta slovenski standard je istoveten z: EN ISO 21528-2:2017
ICS:
07.100.30 Mikrobiologija živil Food microbiology
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 21528-2
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2017
EUROPÄISCHE NORM
ICS 07.100.30
English Version
Microbiology of the food chain - Horizontal method for the
detection and enumeration of Enterobacteriaceae - Part 2:
Colony-count technique (ISO 21528-2:2017)
Microbiologie de la chaîne alimentaire - Méthode Mikrobiologie der Lebensmittelkette - Horizontales
horizontale pour la recherche et le dénombrement des Verfahren für den Nachweis und die Zählung von
Enterobacteriaceae - Partie 2: Technique par comptage Enterobacteriaceae - Teil 2: Koloniezählverfahren (ISO
des colonies (ISO 21528-2:2017) 21528-2:2017)
This European Standard was approved by CEN on 27 April 2017.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a 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 European Standard 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 21528-2:2017 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 21528-2:2017) has been prepared by Technical Committee ISO/TC 34 “Food
products” in collaboration with Technical Committee CEN/TC 275 “Food analysis - Horizontal methods”
the secretariat of which is held by DIN.
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 2018 and conflicting national standards shall
be withdrawn at the latest by January 2018.
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.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association.
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, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 21528-2:2017 has been approved by CEN as EN ISO 21528-2:2017 without any
modification.
INTERNATIONAL ISO
STANDARD 21528-2
Second edition
2017-06
Microbiology of the food chain —
Horizontal method for the detection
and enumeration of
Enterobacteriaceae —
Part 2:
Colony-count technique
Microbiologie de la chaîne alimentaire — Méthode horizontale pour
la recherche et le dénombrement des Enterobacteriaceae —
Partie 2: Technique par comptage des colonies
Reference number
ISO 21528-2:2017(E)
©
ISO 2017
ISO 21528-2:2017(E)
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
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ii © ISO 2017 – All rights reserved

ISO 21528-2:2017(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
4.1 Preparation of initial suspension and decimal dilutions . 2
4.2 Isolation and selection for confirmation . 2
4.3 Confirmation . 2
4.4 Calculation . 2
5 Diluent, culture media and reagent . 2
6 Equipment and consumables . 2
7 Sampling . 3
8 Preparation of test sample . 3
9 Procedure. 3
9.1 General . 3
9.2 Test portion, initial suspension and dilutions . 4
9.3 Inoculation and incubation . 4
9.4 Counting and selection of colonies for confirmation . 4
9.5 Subculturing selected colonies. 4
9.6 Biochemical confirmation tests . 5
9.6.1 Oxidase reaction . 5
9.6.2 Fermentation test . 5
9.6.3 Interpretation of biochemical tests . 5
10 Expression of results . 5
11 Performance characteristics of the method . 5
11.1 Interlaboratory study . 5
11.2 Repeatability limit . 5
11.3 Reproducibility limit . 6
12 Test report . 6
13 Quality assurance . 7
Annex A (normative) Culture media and reagents . 8
Annex B (informative) Method validation studies and performance characteristics .12
Bibliography .15
ISO 21528-2:2017(E)
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
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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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in th
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