EN ISO 20776-1:2020

Susceptibility testing of infectious agents and evaluation of performance of antimicrobial susceptibility test devices - Part 1: Broth micro-dilution reference method for testing the in vitro activity of antimicrobial agents against rapidly growing aerobic bacteria involved in infectious diseases (ISO 20776-1:2019, including Corrected version 2019-12)

This document describes one reference method, broth micro-dilution, for determination of MICs. The MIC can be a guide for the clinician, and reflects the activity of the drug under the described test conditions, by taking into account other factors, such as drug pharmacology, pharmacokinetics, or bacterial resistance mechanisms. This allows categorisation of bacteria as "susceptible" (S), "intermediate" (I), or "resistant" (R). In addition, MIC distributions can be used to define wild type or non-wild type bacterial populations. Although clinical interpretation of the MIC value is beyond the scope of this document, modifications of the basic method are required for certain antimicrobial agent - bacteria combinations to facilitate clinical interpretation. These modifications are included in a separate annex of this document. It is necessary to compare other susceptibility testing methods (e.g. disc diffusion or diagnostic test devices) with this reference method for validation, in order to ensure comparable and reliable results.

Empfindlichkeitsprüfung von Infektionserregern und Leistungsbewertung von Geräten zur antimikrobiellen Empfindlichkeitsprüfung - Teil 1: Referenzmethode zur Testung der In-vitro-Aktivität von antimikrobiellen Substanzen gegen schnell wachsende aerobe Bakterien, die Infektionskrankheiten verursachen (ISO 20776-1:2019, einschließlich der korrigierten Fassung von 2019-12)

Dieses Dokument beschreibt eine Referenzmethode, Mikrodilution, zur MHK Bestimmung. Die MHK kann dem Kliniker als Orientierungshilfe dienen und spiegelt das Maß für die Aktivität einer Substanz unter den beschriebenen Testbedingungen wider. Hierbei können auch andere Faktoren wie die Pharmakologie und Pharmakokinetik des Wirkstoffs oder bakterielle Resistenzmechanismen berücksichtigt werden. Diese Vorgehensweise erlaubt die Einstufung von Bakterien in die Kategorien „sensibel“ (S), „intermediär“ (I) und „resistent“ (R). Die Verteilung der MHK Werte kann zudem dazu dienen, bakterielle Wildtyp Populationen von Nicht Wildtyp Populationen zu unterscheiden. Obgleich die klinische Interpretation des MHK-Werts nicht im Anwendungsbereich dieses Dokuments liegt, sind für bestimmte Kombinationen von antimikrobiellen Substanzen/Erregern Modifikationen der Basismethode erforderlich, um die klinische Interpretation zu erleichtern. Diese Modifikationen sind in einem separaten Anhang dieses Dokuments aufgeführt. Es ist erforderlich, andere Methoden zur Empfindlichkeitsprüfung (z. B. mittels Plattendiffusion oder Diagnoseprüfgeräten) mit dieser Referenzmethode zur Validierung zu vergleichen, um vergleichbare und verlässliche Werte sicherzustellen.

Sensibilité in vitro des agents infectieux et évaluation des performances des dispositifs pour antibiogrammes - Partie 1: Méthode de référence de microdilution en bouillon pour la détermination de la sensibilité in vitro aux agents antimicrobiens des bactéries aérobies à croissance rapide impliquées dans les maladies infectieuses (ISO 20776-1:2019, y compris version corrigée 2019-12)

Le présent document décrit une méthode de référence, la microdilution en bouillon, pour déterminer les CMI. La CMI peut constituer un guide pour le clinicien et reflète l'activité du médicament dans les conditions d'essai décrites, en tenant compte d'autres facteurs tels que la pharmacologie du médicament, la pharmacocinétique ou les mécanismes de résistance bactérienne. Cela permet de classer les bactéries comme étant «sensibles» (S), «intermédiaires» (I) ou «résistantes» (R). En outre, les distributions de CMI peuvent être utilisées pour définir les populations bactériennes de type sauvage ou non sauvage. Bien que l'interprétation clinique de la valeur de la CMI se trouve au-delà du domaine d'application du présent document, des modifications de la méthode de base sont nécessaires pour certaines combinaisons agent antimicrobien-bactérie afin de faciliter l'interprétation clinique. Ces modifications sont incluses dans une annexe séparée du présent document. Il est nécessaire de comparer les autres méthodes d'essai de sensibilité (par exemple, les méthodes de diffusion en gélose ou les dispositifs d'essai de diagnostic) à cette méthode de référence à des fins de validation et pour garantir des résultats comparables et fiables.

Preskus občutljivosti povzročiteljev infekcij na delovanje antimikrobno občutljivih naprav - 1. del: Referenčna metoda za preskus aktivnosti in vitro antimikrobnih povzročiteljev na vpliv bakterij pri nalezljivih boleznih (ISO 20776-1:2019, vključno s popravkom verzije 2019-12)

General Information

• Status: Published
• Publication Date: 30-Jun-2020
• ICS: 11.100 - Laboratory medicine
• ICS: 11.100.20 - Biological evaluation of medical devices
• Technical Committee: CEN/TC 140 - In vitro diagnostic systems
• Drafting Committee: CEN/TC 140 - In vitro diagnostic systems
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 01-Jul-2020
• Completion Date: 01-Jul-2020
• Directive: 98/79/EC - Directive 98/79/EC of the European Parliament and of the Council of 27 October 1998 on in vitro diagnostic medical devices
• Mandate: M/252 - Standardization Mandate to CEN/CENELEC concerning the development of European standards relating to in vitro diagnostic medical devices
• Mandate: M/352 - Supplement n°2 to the CEN's standardisation Mandate concerning methods of analysis for materials and articles intended to come into contact with foodstuffs
• Ref Project: SIST EN ISO 20776-1:2020 - Susceptibility testing of infectious agents and evaluation of performance of antimicrobial susceptibility test devices - Part 1: Broth micro-dilution reference method for testing the in vitro activity of antimicrobial agents against rapidly growing aerobic bacteria involved in infectious diseases (ISO 20776-1:2019, including Corrected version 2019-12)

Relations

• Replaces: EN ISO 20776-1:2006 - Clinical laboratory testing and in vitro diagnostic test systems - Susceptibility testing of infectious agents and evaluation of performance of antimicrobial susceptibility test devices - Part 1: Reference method for testing the in vitro activity of antimicrobial agents against rapidly growing aerobic bacteria involved in infectious diseases (ISO 20776-1:2006)
• Effective Date: 08-Jun-2022

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2020
Nadomešča:
SIST EN ISO 20776-1:2007
Preskus občutljivosti povzročiteljev infekcij na delovanje antimikrobno občutljivih
naprav - 1. del: Referenčna metoda za preskus aktivnosti in vitro antimikrobnih
povzročiteljev na vpliv bakterij pri nalezljivih boleznih (ISO 20776-1:2019, vključno
s popravkom verzije 2019-12)
Susceptibility testing of infectious agents and evaluation of performance of antimicrobial
susceptibility test devices - Part 1: Broth micro-dilution reference method for testing the
in vitro activity of antimicrobial agents against rapidly growing aerobic bacteria involved
in infectious diseases (ISO 20776-1:2019, including Corrected version 2019-12)
Labormedizinische Untersuchungen und In-vitro-Diagnostika-Systeme -
Empfindlichkeitsprüfung von Infektionserregern und Evaluation von Geräten zur
antimikrobiellen Empfindlichkeitsprüfung - Teil 1: Referenzmethode zur Testung der In-
vitro-Aktivität von antimikrobiellen Substanzen gegen schnell wachsende aerobe
Bakterien, die Infektionskrankheiten verursachen (ISO 20776-1:2019, einschließlich der
korrigierten Fassung von 2019-12)
Sensibilité in vitro des agents infectieux et évaluation des performances des dispositifs
pour antibiogrammes - Partie 1: Méthode de référence de microdilution en bouillon pour
la détermination de la sensibilité in vitro aux agents antimicrobiens des bactéries
aérobies à croissance rapide impliquées dans les maladies infectieuses (ISO 20776-
1:2019, y compris version corrigée 2019-12)
Ta slovenski standard je istoveten z: EN ISO 20776-1:2020
ICS:
11.100.10 Diagnostični preskusni In vitro diagnostic test
sistemi in vitro systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 20776-1
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2020
EUROPÄISCHE NORM
ICS 11.100.20 Supersedes EN ISO 20776-1:2006
English Version
Susceptibility testing of infectious agents and evaluation of
performance of antimicrobial susceptibility test devices -
Part 1: Broth micro-dilution reference method for testing
the in vitro activity of antimicrobial agents against rapidly
growing aerobic bacteria involved in infectious diseases
(ISO 20776-1:2019, including Corrected version 2019-12)
Sensibilité in vitro des agents infectieux et évaluation Labormedizinische Untersuchungen und In-vitro-
des performances des dispositifs pour antibiogrammes Diagnostika-Systeme - Empfindlichkeitsprüfung von
- Partie 1: Méthode de référence de microdilution en Infektionserregern und Evaluation von Geräten zur
bouillon pour la détermination de la sensibilité in vitro antimikrobiellen Empfindlichkeitsprüfung - Teil 1:
aux agents antimicrobiens des bactéries aérobies à Referenzmethode zur Testung der In-vitro-Aktivität
croissance rapide impliquées dans les maladies von antimikrobiellen Substanzen gegen schnell
infectieuses (ISO 20776-1:2019, y compris version wachsende aerobe Bakterien, die
corrigée 2019-12) Infektionskrankheiten verursachen (ISO 20776-
1:2019, einschließlich der korrigierten Fassung von
2019-12)
This European Standard was approved by CEN on 22 April 2020.

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, Turkey 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
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 20776-1:2020 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 20776-1:2020) has been prepared by Technical Committee ISO/TC 212 "Clinical
laboratory testing and in vitro diagnostic test systems" in collaboration with Technical Committee
CEN/TC 140 “In vitro diagnostic medical devices” 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 2021, and conflicting national standards shall
be withdrawn at the latest by July 2023.
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 supersedes EN ISO 20776-1:2006.
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, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 20776-1:2019, including Corrected version 2019-12 has been approved by CEN as
INTERNATIONAL ISO
STANDARD 20776-1
Second edition
2019-06
Corrected version
2019-12
Susceptibility testing of infectious
agents and evaluation of performance
of antimicrobial susceptibility test
devices —
Part 1:
Broth micro-dilution reference
method for testing the in vitro activity
of antimicrobial agents against rapidly
growing aerobic bacteria involved in
infectious diseases
Sensibilité in vitro des agents infectieux et évaluation des
performances des dispositifs pour antibiogrammes —
Partie 1: Méthode de référence de microdilution en bouillon pour la
détermination de la sensibilité in vitro aux agents antimicrobiens des
bactéries aérobies à croissance rapide impliquées dans les maladies
infectieuses
Reference number
ISO 20776-1:2019(E)
©
ISO 2019
ISO 20776-1:2019(E)
© ISO 2019
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
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Published in Switzerland
ii © ISO 2019 – All rights reserved

ISO 20776-1:2019(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Test procedures . 3
4.1 General . 3
4.2 Medium . 3
4.3 Antimicrobial agents . 3
4.3.1 General. 3
4.3.2 Preparation of stock solutions . 3
4.3.3 Preparation of working solutions . 4
4.3.4 Preparation of micro-dilution trays . 4
4.3.5 Storage of micro-dilution trays . 4
4.4 Preparation of inoculum . 5
4.4.1 General. 5
4.4.2 Broth culture method . 5
4.4.3 Direct colony suspension method . 5
4.5 Inoculation of micro-dilution trays . 5
4.6 Incubation of micro-dilution trays . 6
4.7 Reading results . 6
4.8 Special test situations where the MIC result might give unreliable results. 6
5 Quality control . 6
Annex A (informative) Requirements for Mueller-Hinton broth . 8
Annex B (informative) Solvents and diluents for making stock solutions of selected
antimicrobial agents . .11
Annex C (informative) Preparation of working dilutions of antimicrobial agents for use in
broth dilution susceptibility tests .16
Annex D (informative) Special test situations .17
Bibliography .18
ISO 20776-1:2019(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
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 sta
...