1、Water quality Enumeration of Legionella BS EN ISO 11731:2017BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06National forewordThis British Standard is the UK implementation of EN ISO 11731:2017. It is identical to ISO 11731:2017. It supersedes BS EN ISO 11731-2:2008 a
2、nd BS 6068-4.12:1998 (dual numbered as ISO 11731:1998), which are withdrawn.BSI, as a member of CEN, is obliged to publish EN ISO 11731:2017 as a British Standard. However, attention is drawn to the fact that during the development of this European Standard, the UK committee voted against its approv
3、al as a European Standard.The standard has many potential variations and interpretations, not only between the method options specified but also within each specified method. This will lead to differences in approach being taken by different laboratories, which are all theoretically valid interpreta
4、tions of this standard. The criteria for the selection of the method variants are based on prior knowledge of the sample characteristics or are based on the sample matrix or type. This assumes that prior knowledge of the sample type is available, which may not always be the case for samples received
5、 by laboratories from third parties. In addition, this assumes that samples within each of the water type categories have a similar constituency or that the constituency of individual samples may not change between sampling events (for example in periodic routine sampling). The standard brings toget
6、her the procedures described in ISO 11731:1998 and EN ISO 11731:2008. There are also additional requirements for some method variations within the standard that were not previously required, such as additional media requirements. Instructions on the choice of approach are described in Annex J and ar
7、e summarised in Figure J.1. This shows 10 method variations which consist of 14 potential procedures and three media types, with the selection of method being based on sample matrix and constituency. In respect to sampling and transport of samples for Legionella analysis, the UK committee believes t
8、hat ISO 11731:1998 and EN ISO 11731:2008 are currently more appropriate. The action level in UK guidance is 100 cfu/l. To detect this level reliably requires that the portion inoculated onto the selective isolation medium would be equivalent to at least 30 ml of the original water sample. Additional
9、ly, the user should be aware that the acid treatment step (for the membrane filtration with washing procedure) is now a 1 in 10 dilution which may affect the theoretical limits of detection of the method. This may therefore not match the action levels stated in national guidelines. This standard als
10、o does not definitively specify an incubation time but gives a range of 7 to 10 days. A note has been added to subclause 8.4.6 to identify that natural samples may require the full 10 days. The UK participation in its preparation was entrusted to Technical Committee EH/3/4, Microbiological methods.A
11、 list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.BRITISH STANDARDBS EN ISO 11731:2017 The British Standards Insti
12、tution 2017 Published by BSI Standards Limited 2017ISBN 978 0 580 79531 2ICS 07.100.20Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2017.Amendments/co
13、rrigenda issued since publicationDate Text affectedBRITISH STANDARD BS EN ISO 11731:2017EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 11731 June 2017 ICS 07.100.20 Supersedes EN ISO 11731-2:2008English Version Water quality - Enumeration of Legionella (ISO 11731:2017) Qualit de leau - Dno
14、mbrement des Legionella (ISO 11731:2017) Wasserbeschaffenheit - Zhlung von Legionellen (ISO 11731:2017) This European Standard was approved by CEN on 12 February 2017. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European St
15、andard 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 (Engl
16、ish, 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,
17、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, Swi
18、tzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR 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 worldwide for CEN natio
19、nal Members. Ref. No. EN ISO 11731:2017 EEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 11731 June 2017 ICS 07.100.20 Supersedes EN ISO 11731-2:2008English Version Water quality - Enumeration of Legionella (ISO 11731:2017) Qualit de leau - Dnombrement des Legionella (ISO 11731:2017) Wasser
20、beschaffenheit - Zhlung von Legionellen (ISO 11731:2017) This European Standard was approved by CEN on 12 February 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 withou
21、t 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 la
22、nguage 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, Denm
23、ark, 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 C
24、OMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR 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 worldwide for CEN national Members. Ref. No. EN ISO 11731:2017 EBS EN
25、ISO 11731:2017EN ISO 11731:2017 (E) 3 European foreword This document (EN ISO 11731:2017) has been prepared by Technical Committee ISO/TC 147 “Water quality“ in collaboration with Technical Committee CEN/TC 230 “Water analysis” the secretariat of which is held by DIN. This European Standard shall be
26、 given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by December 2017, and conflicting national standards shall be withdrawn at the latest by December 2017. Attention is drawn to the possibility that some of the elements of this docume
27、nt may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN ISO 11731-2:2008. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are
28、 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, Por
29、tugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 11731:2017 has been approved by CEN as EN ISO 11731:2017 without any modification. ISO 11731:2017(E)Foreword vIntroduction vi1 Scope . 12 Normative references 13
30、Terms and definitions . 14 Principle 24.1 General . 24.2 Examination. 24.3 Confirmation . 25 Apparatus and glassware 26 Culture media and reagents 37 Sampling 48 Procedure. 48.1 Samples . 48.2 Concentration of water samples 58.2.1 General 58.2.2 Membrane filtration and direct placing of the membrane
31、 filter on culture media 58.2.3 Membrane filtration followed by a washing procedure . 58.3 Sample pre-treatment . 68.3.1 Heat treatment. 68.3.2 Acid treatment . 68.4 Culture 68.4.1 General 68.4.2 Samples with a high concentration of Legionella species and a low concentration of interfering microorga
32、nisms 68.4.3 Samples with a low concentration of Legionella species and a low concentration of interfering microorganisms 68.4.4 Samples with a high concentration of interfering microorganisms 78.4.5 Samples with an extremely high concentration of interfering microorganisms 78.4.6 Incubation 78.4.7
33、Examination of the plates . 78.5 Confirmation of presumptive Legionella colonies on culture media: BCYE agar and BCYEcys agar . 89 Expression of results 810 Test report . 911 Quality assurance .1011.1 General 1011.2 Performance testing of Legionella culture media .1011.3 Preparing working culture an
34、d test suspension for performance testing .10Annex A (informative) Legionella species 12Annex B (normative) Culture media 14Annex C (normative) Diluents 20Annex D (normative) Acid solution.21Annex E (informative) Scraping or rubbing the bacteria from membrane filters 22Annex F (informative) Centrifu
35、gation technique 23 ISO 2017 All rights reserved iiiContents PageBS EN ISO 11731:2017ISO 11731:2017(E)Foreword vIntroduction vi1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 24.1 General . 24.2 Examination. 24.3 Confirmation . 25 Apparatus and glassware 26 Culture media an
36、d reagents 37 Sampling 48 Procedure. 48.1 Samples . 48.2 Concentration of water samples 58.2.1 General 58.2.2 Membrane filtration and direct placing of the membrane filter on culture media 58.2.3 Membrane filtration followed by a washing procedure . 58.3 Sample pre-treatment . 68.3.1 Heat treatment.
37、 68.3.2 Acid treatment . 68.4 Culture 68.4.1 General 68.4.2 Samples with a high concentration of Legionella species and a low concentration of interfering microorganisms 68.4.3 Samples with a low concentration of Legionella species and a low concentration of interfering microorganisms 68.4.4 Samples
38、 with a high concentration of interfering microorganisms 78.4.5 Samples with an extremely high concentration of interfering microorganisms 78.4.6 Incubation 78.4.7 Examination of the plates . 78.5 Confirmation of presumptive Legionella colonies on culture media: BCYE agar and BCYEcys agar . 89 Expre
39、ssion of results 810 Test report . 911 Quality assurance .1011.1 General 1011.2 Performance testing of Legionella culture media .1011.3 Preparing working culture and test suspension for performance testing .10Annex A (informative) Legionella species 12Annex B (normative) Culture media 14Annex C (nor
40、mative) Diluents 20Annex D (normative) Acid solution.21Annex E (informative) Scraping or rubbing the bacteria from membrane filters 22Annex F (informative) Centrifugation technique 23 ISO 2017 All rights reserved iiiContents PageBS EN ISO 11731:2017ISO 11731:2017(E)Annex G (informative) Indirect imm
41、unofluorescent antibody assay for the identification of Legionella species .24Annex H (informative) Performance data 27Annex I (informative) Pre-treatment of water related matrices 31Annex J (normative) Decision matrix .32Bibliography .38iv ISO 2017 All rights reservedBS EN ISO 11731:2017ISO 11731:2
42、017(E)Annex G (informative) Indirect immunofluorescent antibody assay for the identification of Legionella species .24Annex H (informative) Performance data 27Annex I (informative) Pre-treatment of water related matrices 31Annex J (normative) Decision matrix .32Bibliography .38iv ISO 2017 All rights
43、 reserved ISO 11731:2017(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 technical committees. Each member body interested
44、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 Commi
45、ssion (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 sh
46、ould 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 fo
47、r 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 this document is information given for th
48、e 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 ISOs adherence to the World Trade Organization (WTO) principles in t
49、he Technical Barriers to Trade (TBT) see the following URL: www .iso .org/ iso/ foreword .html.This document was prepared by Technical Committee ISO/TC 147, Water quality, Subcommittee SC 4, Microbiological methods.This second edition of ISO 11731 cancels and replaces ISO 11731:1998 and ISO 11731-2:2004, which have been technically revised. ISO 2017 All rights reserved vBS EN ISO 11731:2017ISO 11731:2017(E)IntroductionAfter the first recognized outbreak of Legionnaires disease in 1976, the isolated bacterium was named Legionella pneumophila.
