kSIST FprEN ISO 7899-3:2025

Water quality - Enumeration of intestinal enterococci - Part 3: Most probable number method (ISO/FDIS 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/FDIS 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/FDIS 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/FDIS 7899‑3:2025)

General Information

• Status: Not Published
• Public Enquiry End Date: 01-Aug-2024
• ICS: 07.100.20 - Microbiology of water
• Technical Committee: KAV - Water quality
• Current Stage: 5020 - Formal vote (FV) (Adopted Project)
• Start Date: 04-Apr-2025
• Due Date: 23-May-2025
• Completion Date: 30-Apr-2025
• Ref Project: FprEN ISO 7899-3 - Water quality - Enumeration of intestinal enterococci - Part 3: Most probable number method (ISO/FDIS 7899‑3:2025)

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN ISO 7899-3:2024
01-julij-2024
Kakovost vode - Ugotavljanje števila intestinalnih enterokokov - 3. del: Metoda
najverjetnejšega števila (ISO/DIS 7899-3:2024)
Water quality - Enumeration of intestinal enterococci - Part 3: Most probable number
method (ISO/DIS 7899-3:2024)
Wasserbeschaffenheit - Nachweis und Zählung von intestinalen Enterokokken - Teil 3:
Verfahren zur Bestimmung der wahrscheinlichsten Keimzahl (ISO/DIS 7899-3:2024)
Qualité de l'eau - Dénombrement des entérocoques intestinaux - Partie 3: Méthode du
nombre le plus probable (ISO/DIS 7899-3:2024)
Ta slovenski standard je istoveten z: prEN ISO 7899-3
ICS:
07.100.20 Mikrobiologija vode Microbiology of water
oSIST prEN ISO 7899-3:2024 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN ISO 7899-3:2024
oSIST prEN ISO 7899-3:2024
DRAFT
International
Standard
ISO/DIS 7899-3
ISO/TC 147/SC 4
Water quality — Enumeration of
Secretariat: DIN
intestinal enterococci —
Voting begins on:
Part 3: 2024-05-24
Most probable number method
Voting terminates on:
2024-08-16
Qualité de l'eau — Dénombrement des entérocoques
intestinaux —
Partie 3: Méthode du nombre le plus probable
ICS: 07.100.20
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
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WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS.
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Reference number
ISO/DIS 7899-3:2024(en)
oSIST prEN ISO 7899-3:2024
DRAFT
ISO/DIS 7899-3:2024(en)
International
Standard
ISO/DIS 7899-3
ISO/TC 147/SC 4
Water quality — Enumeration of
Secretariat: DIN
intestinal enterococci —
Voting begins on:
Part 3:
Most probable number method
Voting terminates on:
Qualité de l'eau — Dénombrement des entérocoques
intestinaux —
Partie 3: Méthode du nombre le plus probable
ICS: 07.100.20
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2024
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
or ISO’s member body in the country of the requester.
NATIONAL REGULATIONS.
ISO copyright office
RECIPIENTS OF THIS DRAFT ARE INVITED
CP 401 • Ch. de Blandonnet 8
TO SUBMIT, WITH THEIR COMMENTS,
CH-1214 Vernier, Geneva
NOTIFICATION OF ANY RELEVANT PATENT
Phone: [phone]
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 7899-3:2024(en)
ii
oSIST prEN ISO 7899-3:2024
ISO/DIS 7899-3:2024(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus and glassware . 3
5.1 Apparatus for sterilization by steam (autoclave) .3
5.2 Incubator.3
5.3 Multiple well MPN Tray Sealer .3
5.4 Sterile wide mouthed vessels of at least 110 ml. .3
5.5 Multiple (51 or 97) well MPN Tray .3
5.6 Sterile tubes .3
6 Culture media and reagents . 3
6.1 Basic materials .3
6.2 Diluent .4
6.3 Antifoam B .4
7 Sampling . 4
8 Procedure . 4
8.1 Transportation and storage of samples .4
8.2 Inoculation of media .4
8.2.1 Drinking Water .4
8.2.2 Fresh and Marine Bathing Water . .4
8.3 Incubation .5
8.4 Examination of results .5
9 Expression of results . 5
10 Test report . 5
11 Quality assurance . 5
Annex A (informative) Further microbiological information on intestinal enterococci . 7
Annex B (normative) Composition of Enterolert-DW . 8
Annex C (informative) Validation (performance characteristics) of Enterolert-DW / Quanti-
Tray for the enumeration of intestinal enterococci from water. 9
Bibliography .11

iii
oSIST prEN ISO 7899-3:2024
ISO/DIS 7899-3:2024(en)
Foreword
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This document was prepared by Technical Committee ISO/TC 147, Water Quality, Subcommittee SC 4,
Microbiological Methods.
This is the first edition of this part (ISO 7899:2024), which has been technically revised.
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
oSIST prEN ISO 7899-3:2024
ISO/DIS 7899-3:2024(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 samples for the presence of intestinal enterococci (genus Enterococcus), normally
present in the digestive tract and faeces of humans and homeothermic (warm-blooded) animals, provides an
indication of such contamination.
Their presence can be used to measure the effectiveness of treatment processes during the production
of drinking water together with being indicative of ingress and other integrity issues within storage and
distribution systems for public supplies.
Unlike other parts of this standard, this part can be used to analyse almost all types of water, especially
drinking water, and those samples with high background bacterial counts.
It is important to note that this standard is based upon use of a validated product whose performance
characteristics have be
...