1、Susceptibility testing of g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58infectious agents and evaluation of performance of antimicrobial susceptib
2、ility test devices Part 2: Evaluation of performance of antimicrobial susceptibility test devicesThe European Standard EN ISO 20776-2:2007 has the status of a British StandardICS 11.100.20Clinical laboratory testing and in vitro diagnostic test systems BRITISH STANDARDBS EN ISO 20776-2:2007BS EN ISO
3、 20776-2:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2007 BSI 2007ISBN 978 0 580 54118 6Amendments issued since publicationAmd. No. Date CommentsCompliance with a British Standard cannot confer immunity from legal obligations.
4、National forewordThis British Standard is the UK implementation of EN ISO 20776-2:2007. The UK participation in its preparation was entrusted to Technical Committee CH/212, IVDs.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does no
5、t purport to include all the necessary provisions of a contract. Users are responsible for its correct application.EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 20776-2July 2007ICS 11.100.20English VersionClinical laboratory testing and in vitro diagnostic test systems -Susceptibility testin
6、g of infectious agents and evaluation ofperformance of antimicrobial susceptibility test devices - Part 2:Evaluation of performance of antimicrobial susceptibility testdevices (ISO 20776-2:2007)Systmes dessais en laboratoire et de diagnostic in vitro -Sensibilit in vitro des agents infectieux et val
7、uation desperformances des dispositifs pour antibiogrammes - Partie2: valuation des performances des dispositifs pourantibiogrammes (ISO 20776-2:2007)Labormedizinische Untersuchungen und In-vitro-Diagnostika-Systeme - Empfindlickeitsprfung vonInfektionserregern und Evalution von Gerten zurantimikrob
8、iellen Empfindlichkeitsprfung - Teil 2: Evalutionder Leistung einer Vorrichtung zur antimikrobiellenEmpfindlichkeitsprfung (ISO 20776-2:2007)This European Standard was approved by CEN on 24 June 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the condit
9、ions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three of
10、ficial versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria,
11、 Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE F
12、OR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 20776-2:2007: EForeword This document (EN I
13、SO 20776-2:2007) has been prepared by Technical Committee CEN/TC 140 “In vitro diagnostic medical devices“, the secretariat of which is held by DIN, in collaboration with Technical Committee ISO/TC 212 “Clinical laboratory testing and in vitro diagnostic test systems“. This European Standard shall b
14、e given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by January 2008, and conflicting national standards shall be withdrawn at the latest by January 2008. According to the CEN/CENELEC Internal Regulations, the national standards organ
15、izations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Ro
16、mania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN ISO 20776-2:2007Reference numberISO 20776-2:2007(E)INTERNATIONAL STANDARD ISO20776-2First edition2007-07-01Clinical laboratory testing and in vitro diagnostic test systems Susceptibility testing of infectious agents and eva
17、luation of performance of antimicrobial susceptibility test devices Part 2: Evaluation of performance of antimicrobial susceptibility test devices Systmes dessais en laboratoire et de diagnostic in vitro Sensibilit in vitro des agents infectieux et valuation des performances des dispositifs pour ant
18、ibiogrammes Partie 2: valuation des performances des dispositifs pour antibiogrammes EN ISO 20776-2:2007ii iiiForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is
19、 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
20、 in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to pr
21、epare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that
22、 some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 20776-2 was prepared by the European Committee for Standardization (CEN) Technical Committee CEN/TC 140, In vitro diagnostic medical device
23、s, in collaboration with Technical Committee ISO/TC 212, Clinical laboratory testing and in vitro diagnostic test systems, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement). ISO 20776 consists of the following parts, under the general title Clinical lab
24、oratory 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 inv
25、olved in infectious diseases Part 2: Evaluation of performance of antimicrobial susceptibility test devices EN ISO 20776-2:2007blank1Clinical laboratory testing and in vitro diagnostic test systems Susceptibility testing of infectious agents and evaluation of performance of antimicrobial susceptibil
26、ity test devices Part 2: Evaluation of performance of antimicrobial susceptibility test devices 1 Scope This part of ISO 20776 establishes acceptable performance criteria for antimicrobial susceptibility test (AST) devices that are used to determine minimum inhibitory concentrations (MIC) and/or int
27、erpretive category determinations of susceptible, intermediate and resistant (SIR) strains of bacteria to antimicrobial agents in medical laboratories. This part of ISO 20776 specifies requirements for AST devices (including diffusion test systems) and procedures for assessing performance of such de
28、vices. It defines how a performance evaluation of an AST device is to be conducted. This part of ISO 20776 has been developed to guide manufacturers in the conduct of performance evaluation studies. 2 Normative references The following referenced documents are indispensable for the application of th
29、is document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 20776-1, Clinical laboratory testing and in vitro diagnostic test systems Susceptibility testing of infectious agents and e
30、valuation 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 3 Terms and definitions For the purposes of this document, the following t
31、erms and definitions apply. 3.1 Agreement of test results 3.1.1 category agreement CA agreement of SIR results between a breakpoint test or an MIC test and the reference method (ISO 20776-1) Another representation of the concept: CA100NNEN ISO 20776-2:20072 where NCAis the number of bacterial isolat
32、es with the same SIR category as the reference method category result; N is the total number of bacterial isolates tested NOTE The overall CA is expressed as a percentage. 3.1.2 essential agreement EA MIC result obtained with the AST device that is within plus or minus one doubling dilution step fro
33、m the MIC value established with the reference method (ISO 20776-1) Another representation of the concept: EA100NNwhere NEAis the number of bacterial isolates with an EA; N is the total number of bacterial isolates tested NOTE The overall EA is expressed as a percentage. 3.2 antimicrobial susceptibi
34、lity test device AST device device including all specified components used to obtain test results that allow SIR categorization of bacteria with specific antimicrobial agents NOTE Specific components include inoculators, disposables and reagents, media, disks and readers. Non-specific components, su
35、ch as swabs, pipettes and tubes, are not part of the device. 3.3 breakpoint BP specific values of parameters, such as MICs, on the basis of which bacteria can be assigned to the clinical categories “susceptible”, “intermediate” and “resistant” NOTE For current interpretive breakpoints, reference can
36、 be made to the latest publications of organizations employing this reference method (e.g. CLSI and EUCAST). 3.3.1 susceptible S bacterial strain inhibited in vitro by a concentration of an antimicrobial agent that is associated with a high likelihood of therapeutic success NOTE 1 Bacterial strains
37、are categorized as susceptible by applying the appropriate breakpoints in a defined phenotypic test system. NOTE 2 This breakpoint can be altered due to changes in circumstances (e.g. changes in commonly used drug dosages, emergence of new resistance mechanisms). EN ISO 20776-2:200733.3.2 intermedia
38、te I bacterial strain inhibited in vitro by a concentration of an antimicrobial agent that is associated with uncertain therapeutic effect NOTE 1 Bacterial strains are categorized as intermediate by applying the appropriate breakpoints in a defined phenotypic test system. NOTE 2 This class of suscep
39、tibility implies that an infection due to the isolate can be appropriately treated in body sites where the drugs are physiologically concentrated or when a high dosage of drug can be used. NOTE 3 This class also indicates a “buffer zone”, to prevent small, uncontrolled, technical factors from causin
40、g major discrepancies in interpretations. NOTE 4 These breakpoints can be altered due to changes in circumstances (e.g. changes in commonly used drug dosages, emergence of new resistance mechanisms). 3.3.3 resistant R bacterial strain inhibited in vitro by a concentration of an antimicrobial agent t
41、hat is associated with a high likelihood of therapeutic failure NOTE 1 Bacterial strains are categorized as resistant by applying the appropriate breakpoints in a defined phenotypic test system. NOTE 2 This breakpoint can be altered due to changes in circumstances (e.g. changes in commonly used drug
42、 dosages, emergence of new resistance mechanisms). 3.3.4 non-susceptible NS bacterial strain for which the test result exceeds the susceptible breakpoint and for which there are no established intermediate or resistant breakpoints NOTE This is generally due to lack of strains with resistance to the
43、antimicrobial agent when the breakpoints are defined. 3.4 breakpoint test BPT test that has the principal objective to provide categorical results (SIR) NOTE This can include limited range dilution tests or diffusion tests. 3.5 coordinator person empowered by the manufacturer or investigator with re
44、sponsibility for the entire performance evaluation 3.6 Discrepancies 3.6.1 major discrepancy MD test result by the reference method interpreted as S and an AST device result of R Another representation of the concept: MDSREF100NNEN ISO 20776-2:20074 where NMDis the number of tests that result in a M
45、D; NSREFis the number of susceptible bacterial isolates as determined by the reference method (ISO 20776-1) NOTE The overall MD is expressed as a percentage. 3.6.2 minor discrepancy mD test result by the reference method interpreted as R or S and an AST device result of I; or a reference result inte
46、rpreted as I and an AST device result of R or S Another representation of the concept: mD100NNwhere NmDis the number of tests that result in a mD; N is the total number of bacterial isolates tested NOTE The overall mD is expressed as a percentage. 3.6.3 very major discrepancy VMD test result by the
47、reference method interpreted as R and an AST device result of S Another representation of the concept: VMDRREF100NNwhere NVMD is the number of tests that result in a VMD; NRREFis the number of resistant bacterial isolates as determined by the reference method (ISO 20776-1) NOTE The overall VMD is ex
48、pressed as a percentage. 3.7 evaluation plan description of a planned performance evaluation 3.8 evaluation report description of and conclusions from a performance evaluation EN ISO 20776-2:200753.9 Clinical isolates 3.9.1 fresh isolate isolate recovered from a clinical sample within the previous s
49、even days that has not been frozen or subcultured more than five times 3.9.2 recent isolate isolate recovered from a clinical sample within the previous twelve months 3.9.3 stock isolate isolate recovered from a clinical sample that has been retained, stored or obtained from a culture collection NOTE Stock isolates are usually included because they have known or rare resistance mechanisms, or are of a genus or species for which the antimicrobial agent is indicated but are not commonly isolated. Such organisms are unlikely to be available in
