qa qc for antibiotic testing

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Quality Control and QualityAssurance for Antibiotic Testing26 Sep 2013

Microbiology Technical Workshop

Lily Ng Siew Yong


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Quality assurance

practice of assessing

performance in all

steps of the process to

promote excellent

outcome in medical

care


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Quality control

aggregate of processes and techniques todetect, reduce, and correct deficiencies in an

analytical process.


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Quality Assurance

Processes

With thanks to Derek Brown @ EUCAST Educational Workshop: 31 March 2012


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Quality

Standarddocument-

ation

ExternalQuality

Assurance

InternalQuality

Assurance

Education &

Training

Validation

Evaluation

RoutineQualityControl


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External quality assuranceThe challenge of laboratory procedures with

specimens of known but undisclosed contentExternal laboratory

Or organization

Participating

laboratory

Prepares sample and sendsto participants

Receives sample andperforms testing

Reports resultsReceives and

analyses results

Prepares

report

Analyses reports

& deficiencies

Institutes

corrective actions


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EQAExamples of EQA organizations

College of American Pathologists

Royal College of Pathologists (Australasia)

UKNEQAS

Local reference laboratories


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EQA: benefits Independent assessment of performance

Assessment of performance over time

Comparison with other laboratories

Highlights problem areas

Performance related to guidelines andmethods


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EQA: benefits International differences highlighted

Gives practical experience of difficult tests

(especially if resistance is uncommon)

Provides background information and guidanceon appropriate methods

Performance indicator for accreditation


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EQA: limitations Number of specimens distributed is small

May be considered inappropriate to send some

organisms

Specimens do not reflect routine isolates

Laboratories may not treat specimens as

routine


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EQA: @ CGH Laboratory Survey subscription based on services offered

Survey sample management

Result submission management

Performance assessment


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Internal Quality AssuranceThe challenge of laboratory procedures by repeat

testing of specimens of unknown contentSample

blinded

routine

testing

routine

testing

results results

reported compare

&evaluate


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Internal Quality AssuranceThe challenge of laboratory procedures by repeat

testing of specimens of unknown contentSample Sample

blinded

routine

testing

routine

testing

results results

reported compare

&evaluate

blinded

routine

testing

routine

testing

results results

reported compare

&evaluate


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Internal Quality AssuranceThe challenge of laboratory procedures with spiked

specimensSpiked sample

Routine testing

results

reported

Compare & evaluate


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IQA: Benefits Check of laboratory processes

Identifies:

typographical errors

Inconsistencies between different

technologists

process errors


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IQA: Practical issues Different organisms picked from mixture on

primary plates

Borderline susceptibility leads to variation

Discrepancies with difficult tests

Labor intensive

Sample variability (stored samples)


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IQA: @ CGH LaboratoryTarget: 50 specimens issued monthly

Frequent issues:

Variation in zone diameters

Enumeration of cells

Urine viable count


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AuditProcesses

DocumentationSkills

Knowledge

check - inspect - verify


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Audit: @ CGH LaboratoryAccreditation audit

Internal surveillance

Target 10 % of total test specimens

July 2013: 1,198 of 13,209 specimens

Frequent issues:

Variation in zone diameters

Enumeration of cells

Urine viable count


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Audit: @ CGH LaboratoryErrors

Internal surveillance

10 % of total test specimens

July statistics: 1,198 of 13,209 specimens


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DocumentationStandard operating

procedures user-friendly, not

reference text!

updated regularly

document control

Readily accessible

Examples from:

WHO SOP (SE Asia)

http://apps.searo.who.int/PDS_DOCS/B0217.pdf

HPA (UK) SOP repository

http://www.hpa.org.uk/SMI

Mount Sinai SOP

http://microbiology.mtsinai.on.ca/manual/anti/ind

ex.shtml


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proceduresuser-friendly, not

reference text!

updated regularly

document control

Readily accessible

Examples from:

http://apps.searo.who.int/PDS_DOCS/B0217.pd

f

http://www.hpa.org.uk/SMI


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proceduresuser-friendly, not

reference text!

updated regularly

document control

Readily accessiblehard copy

soft copy


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Evaluation & Validation

For new testing methods / antibiotics introduced

into laboratory

Analytic accuracy

Compare new against

gold s tandard

Precis ion Repeatibility


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Evaluation & Validation @

CGH Laboratory

Introducing use of yeast AST testing by Vitek

Analytic accuracy

Compare results obtained by Vitek

against reference microbroth dilution

method us ing a range of various

species

Precis ion 20 cons ecutive days of parallel testing


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www.hpa.org.uk/webc/hpawebfile/h

paweb_c/1317131674973


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Education & TrainingCompetency

De fine skills to be assessedDe fine how to assess

De fine who will assess

DocumentationRemediation

Continuing professional educationSkills upgrading

Reference

Competency Assessment in the Clinical Microbiology Laboratory. Clin. Microbiol. Rev. July 2004 vol. 17no. 3, 681-694


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Training topics

Importance of proper technique for AST Lab reports vs clinical impact of Staphylococcal AST

Observation of resistance mechanisms

expression in Proteuses

Interpretation and reporting of test results for

Enterococcal AST

Antimicrobials and the beta lactam family drug

family

Interpretation and reporting of test results for

Enterobacteriaceae AST

Extended spectrum beta lactamasesInterpretation and reporting of test results for

non-Enterobacteriaceae ASTcs

Staph lugdunensis:

significance, identification, and susceptibility

Identification, susceptibility testing and result

interpretation ofStrep pneumoniae

ampC beta lactamasesMIC determination by macrobroth and microbroth

methods

Penicillin binding proteins in relation tostaphylococcal growth and drug resistance

Microscan testing

Antimicrobial testing and reading of test

findings

Drug options, result interpretation and reporting for

Staphylococcal AST


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Education & Training @

CGH Laboratory

Insert page of CME AST listing here

Microbiology Training Record

Date TrainingCategory

Topic Trainer Hr LNG GH T ELC H YX H J SM F LH Z SY SFM AP OJL

1 2 /0 3 /2 0 13 Talk Imp or tan ce o f p ro per t ech niq ue f or AST LNG 0.5 Train e r p p AL p p p OFF p p

26/03/2013 P ract icalObservation of resistance machanisms

expression in P roteusesLNG 1 Train e r p p p p p p p p p

11/04/2013 PowerpointAntimicrobials and the beta lactam family

dr ug familyH J / LNG 0.5 Train e r P P P Train e r P P P P P

17 /04/20 13 Pow erpoint Extended spectrum beta lactamases H J / LNG 1 Train e r P AL P Train e r P P P P

22/04/2013 TalkStaph lugdunensis: significance,

ident ification, and suscept ibilityLNG 1 Train e r P P P P P P P P P

24/04 /2013 Powerpoint ampC beta lactamases H J / LNG 1 Train e r P P P Train e r P P P OFF P

29/05/2013 TalkPenicillin binding pr ot eins in relation t o

staphylococcal gro wt h and drug resistanceLNG 0.5 Train e r P P AL P P P P P P

30/05/2013 Powerpoint

Ant imicrob ial testing and reading of test

findings H J / LNG 0.5 Train e r P P AL Train e r P P P P P

11/06 /2013 Talk, part 1

Drug opt ions, result int erpr etation and

repo rt ing for Staphylococcal AST(incl FOX vs OX, E vs CC, Quinolones)

LNG 0.5 Sp e ake r P P P P P P P AL P

11/06 /2013 Talk, part 2

Lab reports vs clinical impact of

Staphyloco ccal AST(incl TGC, RA5, FU, G m, SXT)

LNG 0.5 Sp e ake r P P P P P P P AL P


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Quality Control


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Antibiotic testing

Media

Temperature

Organism

Disc potency

Atmosphere


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QC: Antibiotic testing

Specified routine quality control strains are usedto monitor test performance

Quality control strains must be from a reliable

source

Proper storage to maintain characteristics


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QC Strains: specific tests


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QC Disc: acceptable rangesAcceptable range for ATCC strains


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QC Disc: acceptable ranges


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QC Disc: testing


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Westgard rulesmultiple rules used to monitor a charted process

determines if the process is within acceptablelimits


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Westgard relevant

10x

reject when 10 consecutive

control measurements fall

on one side of the mean.


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QC Disc: monitoring


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QC Disc: failures

ID cause

Cause found:

repeat x 01

Repeat ok = case

close

Repeat out of

range

repeat

No obvious

cause

5 consecutive

days

All within range

= case close

1 out of rangeRe-examine

A tibi ti t ti


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Antibiotic testing:

Common sources of errorMedia

pH Thickness

Storage Contamination

Wrong me dia

Antibiotics

Storage Wrong disc

QC strains

Wrong s trains Inocula


Age

Procedures

Incubation conditions Dis c placement transcription

A tibi ti t ti


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Antibiotic testing:


Storage Thickness

Contamination pH

Wrong me dia

Antibiotics

Storage Wrong disc

QC strains



Age

Procedures


Antibiotic testing:


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Antibiotic testing:


Storage Thickness

Contamination pH

Wrong me dia

Antibiotics

Storage Wrong disc

QC strains

Age Storage

Inocula Contamination

Wrong s trains

Procedures


Antibiotic testing:


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Antibiotic testing:


Storage Thickness

Contamination pH

Wrong me dia

Antibiotics

Storage Wrong disc

QC strains



Age

Procedures

Dis c placement Incubation condition transcription


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QC Disc: Troubleshooting


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QC of Automated Systems Use the recommended quality control strains

Follow manufacturers instructions

Purity check of used inocula

Restricted range of test concentrations means that

the available range may not include the MIC of the

control strain.


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Some concluding thoughts

Quality Assurance


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Quality measure Effort (%)

Clinically relevant testing strategies 15

Testing of reference QC s trains 15

Technical competency 15

Organis m antibiogram verification 15

Supervis or review of results 15

Procedure manual 10

Cumulative antibiogram 5

Proficiency surveys 5

Other 5

Rankin I. D. (2005). Quali ty Assurance/Quali ty Control (QA/QC) In: Coyle M. B. (ed.) Manual of AntimicrobialSusceptibil ity Testing. 1st ed, Washington, D.C.: American Society for Microbiology; 63-89.


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Conclusion


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Can we afford

quality assurance in

microbiology laboratories?


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Can we afford NOT TO HAVE

quality assurance in

microbiology laboratories?

15% of Microbiology reports are wrong!Journal of Hospital Infection. Vol 30, Supp, June 1995, Pages 364371


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Resources

WHO Laboratory Quality Management System

Handbook 2011http://whqlibdoc.who.int/publications/2011/9789241548274_eng.pdf

CLSI M40 susceptibility testing

www.clsi.org

EUCAST quality tableswww.eucast.org/antimicrobial_susceptibility_test ing/qc_tables/

General Reviewhttp://www.intechopen.com/books/latest-research-into-quality-

control/quality-assurance-in-antimicrobial-susceptibility-testing#B23

qa qc for antibiotic testing

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