ECDC EARS-Net External Quality Assessment (EQA) 2014 Derek Brown Peterborough (UK) EUCAST Scientific Secretary UK NEQAS Antimicrobial Susceptibility Testing Specialist Advisory Group Christine Walton and Shila Seaton UK NEQAS for Microbiology, Colindale, London (UK) UK NEQAS
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ECDC EARS-Net External Quality Assessment
(EQA) 2014
Derek Brown Peterborough (UK)
EUCAST Scientific Secretary UK NEQAS Antimicrobial Susceptibility Testing Specialist Advisory Group
Christine Walton and Shila Seaton
UK NEQAS for Microbiology, Colindale, London (UK)
UK NEQAS
Objectives of EARS-Net External Quality Assessment
• To assess the accuracy of antimicrobial
susceptibility test results reported by laboratories
• To assess the comparability of routine antimicrobial susceptibility test results between laboratories and countries
• Education
Participation in EARS-Net EQA
2014 2013 2012 2011 2010
Countries 31 30 30 31 31
Laboratories 905 872 880 911 873
Laboratories responding 93% 92% 92% 90% 88%
Guidelines used in EARS-Net EQA 2014
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AT BE BG CY CZ DE DK EE ES FI FR GR HR HU IE IS IT LT LU LV MT NL NO PL PT RO SE SI SK UK
EUCAST CLSI DIN SFM BSAC
Country
No.
of p
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Trends in antimicrobial susceptibility testing guidelines in EARS-Net
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Perc
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CLSI
All EUCAST
EUCAST
EUCAST-based
Methods use in EARS-Net EQA 2014
Guideline Automated Disk MIC OTHER Total % guideline
BSAC 2 9 0 2 13 1.5
DIN 0 0 1 0 1 0.1
EUCAST 312 239 51 3 605 72.2
CLSI 100 58 6 0 164 19.6
SFM 20 35 0 0 55 6.6
Total 434 341 58 5 838 100
% method 51.8 40.7 6.9 0.6 100
Escherichia coli specimen 2486 CTX-M-15 ESBL
Antimicrobial agent Reference MIC (mg/L) EUCAST CLSI Amoxicillin ≥128 R R Ampicillin ≥128 R R Cefotaxime ≥128 R R Ceftazidime 32-64 R R Ceftriaxone ≥128 R R Amoxicillin-clavulanic acid ≥128 (64) R R Piperacillin-tazobactam 32-64 R I Imipenem 0.12-0.25 S S Meropenem 0.03 S S Doripenem S S Ertapenem 0.12-0.25 S S Ciprofloxacin ≥128 R R Gentamicin ≥128 R R Tobramycin ≥128 R R Amikacin 16 I S
Escherichia coli specimen 2486 Piperacillin-tazobactam MICs 32-64 mg/L EUCAST resistant ( breakpoints S ≤8, R >16 mg/L) CLSI intermediate (breakpoints S ≤16, R ≥ 128 mg/L) • High discrepancy rate in reporting with all guidelines
Escherichia coli specimen 2486 Amikacin MIC 16 mg/L EUCAST intermediate ( breakpoints S ≤8, R >16 mg/L) CLSI susceptible (breakpoints S ≤16, R ≥ 64 mg/L) • High discrepancy rate in reporting with all guidelines, partly
Escherichia coli specimen 2486 Amikacin MIC 16 mg/L EUCAST intermediate ( breakpoints S ≤8, R >16 mg/L) CLSI susceptible (breakpoints S ≤16, R ≥ 64 mg/L) • With EUCAST guidelines more discrepancies with disk
Klebsiella pneumoniae specimen 2487 VIM carbapenemase
Antimicrobial agent Reference MIC (mg/L) EUCAST CLSI Amoxicillin ≥128 R R Ampicillin ≥128 R R Cefotaxime ≥128 R R Ceftazidime ≥128 R R Ceftriaxone ≥128 R R Amoxicillin-clavulanic acid ≥128 (64) R R Piperacillin-tazobactam ≥128 R R Imipenem 64 R R Meropenem ≥128 R R Doripenem R R Ertapenem ≥128 R R Ciprofloxacin ≥128 R R Gentamicin 1 S S Tobramycin 16 R R Amikacin 16 I S
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Antimicrobial agent
Klebsiella pneumoniae specimen 2487
Klebsiella pneumoniae specimen 2487 Amikacin MIC 16 mg/L
Aminoglycoside susceptibility was typical for an organism producing AAC(6')I, i.e. Gentamicin susceptible (MIC 1 mg/L) Tobramycin resistant (MIC 16 mg/L) Amikacin borderline (MIC 16 mg/L) EUCAST intermediate (breakpoints S ≤8, R >16 mg/L) CLSI susceptible (breakpoints S ≤16, R ≥ 64 mg/L) • High discrepancy rate in reporting with all guidelines,
Klebsiella pneumoniae specimen 2487 Amikacin MIC 16 mg/L
• More discrepancies with disk diffusion method
• EUCAST expert rule note that acquired AAC(6')I may not confer phenotypic resistance to amikacin despite modification of amikacin, and that such organisms should be reported intermediate even if they appear susceptible. Some participants may have edited S test results to I.
Antimicrobial agent Reference MIC (mg/L) EUCAST CLSI
Penicillin 64 R R Cefoxitin ≥128 R R Oxacillin ≥128 R R Vancomycin 4 R I Teicoplanin 8-16 R S/I Erythromycin ≥128 R R Clindamycin ≥128 R R Gentamicin 128 – 256 R R Fusidic acid 0.06 - 0.12 S - Ciprofloxacin 16 R R Rifampicin ≥128 R R Tetracycline 64 R R
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Staphylococcus aureus specimen 2489
Staphylococcus aureus specimen 2489 Vancomycin resistance MIC 4 mg/L
EUCAST resistant ( breakpoints S ≤ 2, R > 2 mg/L) CLSI intermediate (breakpoints S ≤ 2, R ≥ 16 mg/L)
• High error rate in reporting with all guidelines
Streptococcus pneumoniae specimen 2489 Penicillin “intermediate” (MIC 0.25 – 0.5 mg/L) Site of infection unspecified • Breakpoints for isolates other than meningitis EUCAST S ≤0.06 R >2 mg/L CLSI (parenteral) S ≤2 R ≥8 mg/L CLSI (oral) S ≤0.06 R ≥2 mg/L • Meningitis isolate EUCAST S ≤0.06 R >0.06 mg/L CLSI S ≤0.06 R ≥0.12 mg/L Guideline n %S %I %R EUCAST 563 17.4 75.5 7.1 CLSI 116 46.5 45.7 7.8
Streptococcus pneumoniae specimen 2489 Penicillin MIC 0.25 – 0.5 mg/L • Pneumonia isolate With EUCAST breakpoints for higher doses used in
pneumonia, and CLSI parenteral breakpoints for non-meningitis isolates, expected result “Susceptible”