1、Microbiology of the food chain - Horizontal method for the detection and enumeration of Enterobacteriaceae Part 2: Colony-count technique (ISO 21528-2:2017) BS EN ISO 21528-2:2017BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06EUROPEAN STANDARD NORME EUROPENNE EUROPI
2、SCHE NORM EN ISO 21528-2 July 2017 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 chane alimentaire - Mthode horizontale pour la recherche
3、 et le dnombrement des Enterobacteriaceae - Partie 2: Technique par comptage des colonies (ISO 21528-2:2017) Mikrobiologie der Lebensmittelkette - Horizontales Verfahren fr den Nachweis und die Zhlung von Enterobacteriaceae - Teil 2: Koloniezhlverfahren (ISO 21528-2:2017) This European Standard was
4、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 natio
5、nal 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 langua
6、ge 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,
7、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 COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORM
8、UNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2017 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 21528-2:2017 ENational forewordThis British Standard is the UK implementation of EN ISO 21528-2:2017. It
9、is identical to ISO 21528-2:2017. It supersedes BS ISO 21528-2:2004, which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee AW/9, Microbiology.A list of organizations represented on this committee can be obtained on request to its secretary.This publication d
10、oes not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2017 Published by BSI Standards Limited 2017ISBN 978 0 580 84391 4ICS 07.100.30Compliance with a British Standard cannot confer immunity from le
11、gal obligations. This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 August 2017.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN ISO 21528-2:2017EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 215
12、28-2 July 2017 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 chane alimentaire - Mthode horizontale pour la recherche et le dnombrement d
13、es Enterobacteriaceae - Partie 2: Technique par comptage des colonies (ISO 21528-2:2017) Mikrobiologie der Lebensmittelkette - Horizontales Verfahren fr den Nachweis und die Zhlung von Enterobacteriaceae - Teil 2: Koloniezhlverfahren (ISO 21528-2:2017) This European Standard was approved by CEN on 2
14、7 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
15、 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 t
16、he 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, Ir
17、eland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Mana
18、gement Centre: Avenue Marnix 17, B-1000 Brussels 2017 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 21528-2:2017 EBS EN ISO 21528-2:2017EN ISO 21528-2:2017 (E) 3 European foreword This document (EN ISO 21528-2:2017) has been
19、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
20、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 ident
21、ifying 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 imple
22、ment 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,
23、 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. ISO 21528-2:2017(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and
24、 definitions . 14 Principle 24.1 Preparation of initial suspension and decimal dilutions 24.2 Isolation and selection for confirmation 24.3 Confirmation . 24.4 Calculation 25 Diluent, culture media and reagent 26 Equipment and consumables 27 Sampling 38 Preparation of test sample . 39 Procedure. 39.
25、1 General . 39.2 Test portion, initial suspension and dilutions 49.3 Inoculation and incubation 49.4 Counting and selection of colonies for confirmation . 49.5 Subculturing selected colonies 49.6 Biochemical confirmation tests 59.6.1 Oxidase reaction . 59.6.2 Fermentation test 59.6.3 Interpretation
26、of biochemical tests . 510 Expression of results 511 Performance characteristics of the method . 511.1 Interlaboratory study 511.2 Repeatability limit 511.3 Reproducibility limit 612 Test report . 613 Quality assurance 7Annex A (normative) Culture media and reagents 8Annex B (informative) Method val
27、idation studies and performance characteristics 12Bibliography .15 ISO 2017 All rights reserved iiiContents PageBS EN ISO 21528-2:2017ISO 21528-2:2017(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 24.1 Preparation of initial suspension and decim
28、al dilutions 24.2 Isolation and selection for confirmation 24.3 Confirmation . 24.4 Calculation 25 Diluent, culture media and reagent 26 Equipment and consumables 27 Sampling 38 Preparation of test sample . 39 Procedure. 39.1 General . 39.2 Test portion, initial suspension and dilutions 49.3 Inocula
29、tion and incubation 49.4 Counting and selection of colonies for confirmation . 49.5 Subculturing selected colonies 49.6 Biochemical confirmation tests 59.6.1 Oxidase reaction . 59.6.2 Fermentation test 59.6.3 Interpretation of biochemical tests . 510 Expression of results 511 Performance characteris
30、tics of the method . 511.1 Interlaboratory study 511.2 Repeatability limit 511.3 Reproducibility limit 612 Test report . 613 Quality assurance 7Annex A (normative) Culture media and reagents 8Annex B (informative) Method validation studies and performance characteristics 12Bibliography .15 ISO 2017
31、All rights reserved iiiContents PageBS EN ISO 21528-2:2017ISO 21528-2:2017(E)ForewordISO (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
32、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 clo
33、sely 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
34、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 p
35、atent 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
36、 used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical
37、 Barriers to Trade (TBT) see the following URL: www .iso .org/ iso/ foreword .html.This document was prepared by the European Committee for Standardization (CEN) Technical Committee CEN/TC 275, Food analysis Horizontal methods, in collaboration with ISO Technical Committee ISO/TC 34, Food products,
38、Subcommittee SC 9, Microbiology in accordance with the agreement on technical cooperation between ISO and CEN (Vienna Agreement).This second edition cancels and replaces the first edition (ISO 21528-2:2004), which has been technically revised with the following main changes: the confirmation step ha
39、s been changed by replacing glucose agar by glucose OF medium; precision data based on the results of an interlaboratory study using the method according to this revised edition has been included in an informative annex.A list of all the parts in the ISO 21528 series can be found on the ISO website.
40、 iv ISO 2017 All rights reservedBS EN ISO 21528-2:2017ISO 21528-2:2017(E)ForewordISO (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 tech
41、nical 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
42、 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 need
43、ed 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 paten
44、t 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 use
45、d in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Bar
46、riers to Trade (TBT) see the following URL: www .iso .org/ iso/ foreword .html.This document was prepared by the European Committee for Standardization (CEN) Technical Committee CEN/TC 275, Food analysis Horizontal methods, in collaboration with ISO Technical Committee ISO/TC 34, Food products, Subc
47、ommittee SC 9, Microbiology in accordance with the agreement on technical cooperation between ISO and CEN (Vienna Agreement).This second edition cancels and replaces the first edition (ISO 21528-2:2004), which has been technically revised with the following main changes: the confirmation step has be
48、en changed by replacing glucose agar by glucose OF medium; precision data based on the results of an interlaboratory study using the method according to this revised edition has been included in an informative annex.A list of all the parts in the ISO 21528 series can be found on the ISO website. iv
49、ISO 2017 All rights reserved ISO 21528-2:2017(E)IntroductionThis document is intended to provide general guidance for the examination of products not dealt with by existing International Standards and to be taken into account by organizations preparing microbiological test methods for application to foods or animal feeding stuffs. Because of the large variety of products within this field of application, these guidelines may not be appropriate in every detail for certain products, and for some other products, it may be necessary to use d
