SIST EN ISO 7899-3:2025
(Main)Water quality - Enumeration of intestinal enterococci - Part 3: Most probable number method (ISO 7899-3:2025)
Water quality - Enumeration of intestinal enterococci - Part 3: Most probable number method (ISO 7899-3:2025)
This document specifies a method for the enumeration of intestinal enterococci in water, including Enterococcus faecalis, Enterococcus faecium, Enterococcus durans, Enterococcus avium, Enterococcus gallinarum, Enterococcus hirae, Enterococcus casselifavus. The method is based on the growth of target organisms in a liquid medium and calculation of the “most probable number” (MPN) of microorganisms by reference to MPN tables or using suitable MPN informatic programs.
This method can be applied to drinking water and bathing water (fresh or marine), together with other similar water types including those containing an appreciable amount of suspended matter, and allows the detection of enterococci at 1 colony-forming unit (CFU) per 100 ml with definitive results within (26 ± 2) h in the presence of heterotrophic bacteria in numbers as high as 1 × 106 per 100 ml of sample.
For bathing waters, fresh and marine, enterococci are best enumerated when samples are diluted 1:10.
The test specified in this document relies upon the detection of intestinal enterococci based upon expression of the enzyme ß-D-glucosidase and provides a confirmed result in 24 h without further testing of positive wells.
This document does not apply to bottled waters, for which the method has not been validated and therefore is outside the scope of this document, unless appropriate validation of performance of this method has been undertaken by the laboratory prior to use.
Wasserbeschaffenheit - Nachweis und Zählung von intestinalen Enterokokken - Teil 3: Verfahren zur Bestimmung der wahrscheinlichsten Keimzahl (ISO 7899-3:2025)
Dieses Dokument legt ein Verfahren zur Zählung von intestinalen Enterokokken in Wasser fest, einschließlich Enterococcus faecalis, Enterococcus faecium, Enterococcus durans, Enterococcus avium, Enterococcus gallinarum, Enterococcus hirae, Enterococcus casselifavus. Das Verfahren basiert auf dem Wachstum von Zielorganismen in einem flüssigen Medium und der Berechnung der wahrscheinlichsten Keimzahl (MPN, en: most probable number) der Mikroorganismen anhand von MPN Tabellen oder geeigneten MPN Informatikprogrammen.
Dieses Verfahren kann bei Trinkwasser und Badewasser (Süß- oder Salzwasser) sowie anderen ähnlichen Wasserarten angewendet werden, einschließlich solcher, die eine erhebliche Menge an Schwebstoffen enthalten, und es ermöglicht den Nachweis von Enterokokken mit 1 Koloniebildende Einheit (KBE) pro 100 ml mit definitiven Ergebnissen innerhalb von (26 ± 2) h bei einer Anwesenheit heterotropher Bakterien in einer Anzahl von bis zu 1 × 106 je 100 ml-Probe.
Enterokokken in Badegewässern, Binnen- und Meeresgewässern lassen sich am besten zählen, wenn die Proben 1 : 10 verdünnt werden.
Die in diesem Dokument beschriebene Prüfung stützt sich auf den Nachweis intestinaler Enterokokken durch die Expression des Enzyms ß D Glucosidase und liefert ohne weitere Prüfung positiver Probenvertiefungen innerhalb von 24 h ein bestätigtes Ergebnis.
Dieses Dokument gilt nicht für abgefülltes Wasser, für das das Verfahren nicht validiert wurde und das deshalb nicht in den Anwendungsbereich dieses Dokuments fällt, sofern nicht vom Labor vor der Anwendung eine angemessene Validierung der Leistung dieses Verfahrens durchgeführt wurde.
WARNUNG — Anwender dieses Dokuments sollten mit der üblichen Laborpraxis vertraut sein. Dieses Dokument erhebt nicht den Anspruch, auf alle gegebenenfalls zutreffenden Sicherheitsfragen im Zusammenhang mit seiner Anwendung einzugehen. Es liegt in der Verantwortung des Anwenders, angemessene Sicherheits und Schutzmaßnahmen zu treffen.
WICHTIG — Es ist unerlässlich, dass nach diesem Dokument durchgeführte Untersuchungen von entsprechend qualifiziertem Personal durchgeführt werden.
Qualité de l'eau - Dénombrement des entérocoques intestinaux - Partie 3: Méthode du nombre le plus probable (ISO 7899-3:2025)
Le présent document spécifie une méthode permettant de dénombrer les entérocoques intestinaux dans l'eau, y compris l'Enterococcus faecalis, l'Enterococcus faecium, l'Enterococcus durans, l'Enterococcus avium, l'Enterococcus gallinarum, l'Enterococcus hirae, l'Enterococcus casselifavus. La méthode est basée sur la croissance d'organismes cibles dans un milieu liquide et sur le calcul du « nombre le plus probable » (NPP) de micro-organismes en fonction de tables NPP ou à l’aide de programmes informatiques NPP.
Cette méthode peut être appliquée à l'eau potable et à l'eau de baignade (douce ou marine), ainsi qu'à d'autres types d'eaux similaires (y compris celles contenant une quantité détectable de matières en suspension), et permet la détection d'entérocoques à une concentration de 1 unité formant colonie (UFC) pour 100 ml avec des résultats définitifs en (26 ± 2) heures en présence de bactéries hétérotrophes en nombres pouvant atteindre 1 × 106 pour 100 ml d’échantillon.
Dans le cas des eaux de baignade, douces et marines, les entérocoques sont mieux dénombrés lorsque les échantillons sont dilués au 1/10.
L’essai spécifié dans le présent document repose sur la détection d'entérocoques intestinaux basée sur l'expression de l'enzyme ß‑D‑glucosidase et fournit un résultat confirmé en 24 heures sans essai supplémentaire des puits positifs.
Le présent document ne s'applique pas aux eaux embouteillées, pour lesquelles cette méthode n'a pas été validée et qui sont, par conséquent, en dehors du champ d'application du présent document, à moins qu'une validation appropriée des performances de cette méthode n'ait été entreprise par le laboratoire avant son utilisation.
Kakovost vode - Ugotavljanje števila intestinalnih enterokokov - 3. del: Metoda najverjetnejšega števila (ISO 7899-3:2025)
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-november-2025
Kakovost vode - Ugotavljanje števila intestinalnih enterokokov - 3. del: Metoda
najverjetnejšega števila (ISO 7899-3:2025)
Water quality - Enumeration of intestinal enterococci - Part 3: Most probable number
method (ISO 7899-3:2025)
Wasserbeschaffenheit - Nachweis und Zählung von intestinalen Enterokokken - Teil 3:
Verfahren zur Bestimmung der wahrscheinlichsten Keimzahl (ISO 7899-3:2025)
Qualité de l'eau - Dénombrement des entérocoques intestinaux - Partie 3: Méthode du
nombre le plus probable (ISO 7899-3:2025)
Ta slovenski standard je istoveten z: EN ISO 7899-3:2025
ICS:
07.100.20 Mikrobiologija vode Microbiology of water
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 7899-3
EUROPEAN STANDARD
NORME EUROPÉENNE
August 2025
EUROPÄISCHE NORM
ICS 07.100.20
English Version
Water quality - Enumeration of intestinal enterococci -
Part 3: Most probable number method (ISO 7899-3:2025)
Qualité de l'eau - Dénombrement des entérocoques Wasserbeschaffenheit - Nachweis und Zählung von
intestinaux - Partie 3: Méthode du nombre le plus intestinalen Enterokokken - Teil 3: Verfahren zur
probable (ISO 7899-3:2025) Bestimmung der wahrscheinlichsten Keimzahl (ISO
7899-3:2025)
This European Standard was approved by CEN on 9 June 2025.
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, 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
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 7899-3:2025 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
This document (EN ISO 7899-3:2025) 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 given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by February 2026, and conflicting national standards
shall be withdrawn at the latest by February 2026.
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 7899-3:2025 has been approved by CEN as EN ISO 7899-3:2025 without any
modification.
International
Standard
ISO 7899-3
First edition
Water quality — Enumeration of
2025-07
intestinal enterococci —
Part 3:
Most probable number method
Qualité de l'eau — Dénombrement des entérocoques
intestinaux —
Partie 3: Méthode du nombre le plus probable
Reference number
ISO 7899-3:2025(en) © ISO 2025
ISO 7899-3:2025(en)
© ISO 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 7899-3:2025(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 2
6 Culture media and reagents . 3
6.1 General .3
6.2 Basic materials .3
6.3 Diluent .3
6.4 Antifoam .3
7 Sampling, transportation and storage of samples . 3
8 Procedure . 3
8.1 Inoculation of media .3
8.1.1 Drinking water .3
8.1.2 Fresh and marine bathing water .4
8.2 Incubation .4
8.3 Examination of results .4
9 Expression of results . 4
10 Test report . 4
11 Quality assurance . 5
Annex A (informative) Additional microbiological information on intestinal enterococci . 6
Annex B (normative) Composition of Enterolert-DW . 7
Annex C (informative) Validation (performance characteristics) of Enterolert-DW / Quanti-
Tray for the enumeration of intestinal enterococci from water. 8
Bibliography .10
iii
ISO 7899-3:2025(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 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 147, Water quality, Subcommittee SC 4,
Microbiological methods.
A list of all parts in the ISO 7899 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.
iv
ISO 7899-3:2025(en)
Introduction
The presence and extent of faecal pollution is an important factor in assessing the quality of a body of water
and the risk to human health from enteric infection.
Examination of water
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.