Educational Workshop - ESCMID

Educational Workshop EW01: Antimicrobial susceptibility testing with EUCAST breakpoints and methods Arranged with EUCAST (The European Committee on Antimicrobial Susceptibility Testing)

Convenors: Gunnar Kahlmeter, Växjö, SE

Rafael Canton Moreno, Madrid, ES

Faculty: Rafael Canton Moreno, Madrid, ES

Susan J. Howard, Manchester, UK Johan W. Mouton, Rotterdam, NL

Iztok Strumbelj, Murska Sobota, SI

Alasdair P. MacGowan, Bristol, UK Derek F.J. Brown, Peterborough, UK Sören G. Gatermann, Bochum, Germany

Ronald N. Jones, North Liberty, IA, USA

Marked in red = no handouts available

Canton - Update on EUCAST methods and breakpoints

Update on EUCAST methods and breakpoints, 2015

www.EUCAST.org

Departamento de Microbiología IIUniversidad Complutense. Madrid

www.eucast.org

http://www.eucast.orgTop countries % visits-Q2014

Unknown 17,6

USA 10,6

Germany 10.1

UK 6.1

Netherlands 5.7

Switzerland 4.0

Itally 3.9

Sweden 3.6

Denmark 3.3

Belgium 2.8

France 2.2

Norway 1.9

Spain 1.8

Austria 1.7

Finland 1.7

China 1.7

Australia 1.5

Japan 1.5

Visits:

- 50.000-60.000 visitors/month (60% from EU)

Pages more visited (each visitor may seeeach page more than once)

- home 45.9%- clinical breakpoints 69.2% - MIC/zone distributions 5.5% - expert rules 3.3%- resistance mechanisms 3.2%


http://www.eucast.org

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No. of visitors per month

2012 20142013

EUCAST-related publications

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EUCAST General Committee (GC)All European Countries + Countries from outside

EUCAST Steering CommitteeBSAC, CA‐SFM, CRG, NWGA, SRGA, NAK

+ 2 reps from the GC ± 1‐2 “visiting” members from the GC

SubcommitteesAntifungals (AFST)

VetCASTWhole genome sequencing and AST

National Breakpoint CommitteesF, N, NL, S, UK, DE

Experts (ECDC Networks,

ESCMID Study Groups) Industry

NACs = National Antimicrobial Susceptibility

Testing Committees

Contract 2011-14

2015 www.eucast.org


EUCAST translations


National Antimicrobial Committees (NACs) outside Europe

Countries with a NAC operating under EUCAST standards

Countries with interest to establish a NAC under EUCAST standards

EUCAST subcommittees

Subcommittees

Subcommittee on Antifungal Susceptibility Testing (EUCAST AFST) Standing subcommittee established in 2002

Veterinary Subcommittee on Antimicrobial Susceptibility Testing (VetCAST). Standing Subcommittee established in 2015

Subcommittee on the role of whole genome sequencing in antimicrobial susceptibility testing. Established in 2015.

Former subcommittees

Subcommittee on Expert Rules and Intrinsic Resistance. Established in 2007, disbanded 2011.

Subcommittee on Anaerobe Susceptibility Testing Established in 2007, disbanded 2011.

Subcommittee on the detection of resistance mechanisms of clinical and/or public health importance. Established in 2011, disbanded 2014.


Veterinary committee on AST (VetCAST)

Formed in 2015, dealing with antimicrobial susceptibility testing(AST) of bacterial pathogens of animal origin and zoonotic bacteria

Remit…

- To establish a science‐based committee to cooperate with EUprofessionals in veterinary medicine, EMA, ECDC and EFSA

- To determine antimicrobial breakpoints specific to the veterinary field

- To harmonize veterinary AST in the EU

- To provide AST/antimicrobial therapy education in the veterinary field

- To initiate and coordinate EU research aimed at filling the currentgaps in veterinary AST

– Missing or insufficient veterinary specific breakpoints– Optimized methods for AST of bacterial pathogens of animal origin

- To ensure that AST protocols and interpretive criteria are freelyaccessible online through the EUCAST website

Chairman (Dik Mevious), Secretary (Peter Damborg), …

Subcommittee on the role of whole genomesequencing (WGS) in AST of bacteria

Formed in 2015 with the following remit

- perform a systematic literature review of the role of WGS in antimicro-bial susceptibility testing (AST) of bacteria (excluding mycobacteria)

- determine the sensitivity and specificity of WGS compared withstandard phenotypic AST

- determine how WGS may be applied in clinical laboratories and the likely implications for phenotypic and other genotypic methods in use

- determine the epidemiological implications of using WGS

- determine the clinical implications of WGS for the selection of antimicrobial therapy

- determine the principles of how the result of WGS for AST would bebest presented to clinical users

- describe the drivers and barriers to routine use of WGS

Coordinator (Alasdair MacGowan), ...

EUCAST Development Laboratories (Nov 2014 …)

Development and maintenance of EUCAST antimicrobialsusceptibility testing (AST) methods

- Bacteria (Växjö, Sweden)- Fungi (Statens Serum Institut, Copenhagen, Denmark)

Coordination of he EUCAST Network Laboratories in thedevelopment and validation of EUCAST methods, training,education and technical support to other laboratories.

EUCAST network laboratories (Nov 2014 …)

Microbiology laboratories with particular expertise andtraining in EUCAST AST for bacteria and/or fungal isolates

Develop, validate and troubleshoot EUCAST methodsand/or train and educate other laboratories

Assist clinical breakpoint development by providingspecies -specific MIC datasets


Templete for RDs, 40 documents (New: ceftaroline;

Drafted: cetobiprol, macrolides, penicillins, cephalosporins, SXT,

aztreonam, choramphenicol)

SOP 8.0. Format and updating of EUCAST documents

SOP 9.0. Procedure for establishingzone diameter breakpoints andQC criteria for new antibiotics

Implementation of EUCAST break-points for AST (Euro surveillance)

Euro Surveillance 2015;20:pii=21008

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CLSIAll EUCAST

Uptake of EUCAST guidelines by participants in UKNEQAS (updated)

Courtesy of Derek Brown and Christine Walton

MIC vs zone diameters files Disk diffusion manual and slide show Breakpoint and QC tables v5.0 Compliance of manufacturers

Frequently Asked QuestionsMarch 23rd , 2015


EUCAST breakpoints, 2015 (version 5.0)

Links to different pages (microorganisms) and EUCAST documents:- guidance documents, expert rules- detection of resistance mechanisms- breakpoints for topical use of antimicrobial agents



Guidance on reading EUCAST breakpoint tables

New format for comments


New and revised breakpoints

Enterobacteriaceae Amikacin (zone diameters)

Staphylococcus spp. Telavancin (new)

Moraxella catarrhalis Ceftaroline (change from dash to IE)

Neisseria menigitidis Ciprofloxacin (remove intermediate catergory)

Neisseria gonorrhoeae Cefpodoxime,ceftibuten (change from IE to dash)

Clostridium difficile Fidaxomicin (new)

M. tuberculosis Delamanid and bedaquiline (new)


New EUCAST breakpoints, April 2015

Staphylococcus spp. Dalbavancin, Oritavancin, Tedizolid (new)

Strep. group A, B, C, G Dalbavancin, Oritavancin, Tedizolid (new)

Strep. anginosus group Dalbavancin, Oritavancin, Tedizolid (new)


Rewording of notes, new notes

Telavancin, tigecycline, Information on testing conditionsdaptomycin, fosfomycin

Aztreonam Enterobacteriaceae, Pseudomonas spp.

Trimethoprim-sulfameth. Stenotrophomonas maltophiliaEnterococcus spp.

Cephalosporins Staphylococcus spp.

Clindamycin Strept. groups A, B, C and DStreptococcus pneumoniaeViridans group streptococci

Quality control data

Haemophillus influenzae Moraxella catharralis Pasterurella multocida

Clindamycin induble phenotype (MLSB)


Inducible clindamycin resistance can be detected by antagonism ofclindamycin activity by a macrolide agent

Place the erythromycin and clindamycin disks 12-20 mm apart (edge toedge) and look for antagonism (the D phenomenon)

Antagonisms Report clindamycin

Organisms Comment to the report

No detected S Staphylococcus spp.

Detected R Staphylococcus spp. Clindamycin may still be used for short-term therapy of less serious skin and soft tissue infections as constitutive resistance is unlikely to develop during such therapy

R Strept. group A,B,C,GS. pneumoniaeViridans g. streptococci


Mycobacterium tuberculosis EUCAST Clinical Breakpoint Table v. 5.0, valid from 2015-01-01

EUCAST was tasked with suggesting to EMA breakpoints for new agents but has so far not addressed breakpoints for existing agents.

Recommended methods for antimicrobial susceptibility testing of mycobacteria are currently under discussion.

S ? R >

Delamanid 0,06 0,06

Bedaquiline 0.25 0.25

MIC breakpoint (mg/L)

Notes Numbers for comments on MIC breakpoints

EUCAST breakpoints: Delamanid and Bedaquiline

EUCAST Clinical Breakpoint Table v. 5.0, valid from 2015-01-01

≤

EUCAST breakpoints

Reviewed breakpoints with no changes:

- linezolid and staphylococci and enterococci

- teicoplanin and coagulase negative staphylococci

- fluoroquinolones and Corynebacterium spp.

- metronidazole and anaerobes

- daptomycin and enterococci

Superficial skin and external eye and ear infections but notfor bowel decontamination or inhaled agents

EUCAST has not found a consensus to resolve different opinions

- use ECOFFs for agents when used topically - use clinical breakpoints when available and ECOFF when

there are not clinical breakpoints

Acceptable distributions are not available for all topical agents

Only specific breakpoints for nasal decolonisation of S. aureuswith mupirocin is supported with clinical data

If tissue is involved the use of systemic treatment and systemic breakpoints should be considered

Guidance note on breakpoints for topical agents


ECOFFs and systemic clinical breakpoints for antimicrobial agentsthat are used topically

- = inappropriate combination; IE = insufficient evidence to set a clinical breakpoint; ND = No ECOFF defined on EUCAST MIC distribution website 1Agents also available for systemic use 2Breakpoints for nasal decontamination S≤1, R>256 mg/l.

Guidance note on breakpoints for topical agents

New and ongoing breakpoints (BP) and methodology

- EMA β-lactam-β-lactamase inhibitor combinations, cephalosporinsaminoglycosides, and oxazolidinones, pleuromutillin

guidelines for companies submitting anti-mycobacterial agents

- CLSI colistin and methodology

- NACs temocillin, nitroxoline, spiramycin, tigecycline, sulbactam

- Antimicrobial groups: fluoroquinolones and carbapenems

- Neisseria gonorrhoeae and different antimicrobials

- Breakpoints for Actinomyces spp., Eikenella corrhodens

New RD documents (new agents and new RD due to revised BP)

New documents, technical notes / guidance documents - new version of expert rules (v3)- SOPs (revision of breakpoints)

New EUCAST definition of the intermediate category and ECOFF

EUCAST: What is coming for 2015-16?

www.eucast.org


EUCAST Development Laboratory

andEUCAST Network

laboratories

Acknowledgements

More information:

- Saturday 16:30 – 18:30, Hall B Resurrecting old antimicrobial agents

- Sunday 09.00 – 10.30, Meeting Room 19EUCAST Subcommittee on Antifungal Susceptibility Testing (AFST) General Committee Meeting

11.30 – 12.30, Hall BBenefits and challenges of site-specificbreakpoints

- Monday 13.00 – 14.30, Hall NEUCAST General Committee meeting

17.30 – 18.30, Meeting Room 6EUCAST Veterinary Subcommittee onAntimicrobial Susceptibility Testing (VetCAST)

- Tuesday 07.45 – 08.45, Hall IMeet the Experts. EUCAST: frequently askedquestions

Howard ‐ Antifungal breakpoints and susceptibility testing

Anti-Fungal Susceptibility Testing Subcommittee

EUCAST‐AFST: MC Arendrup (Chair), WW Hope (Secretary), M Cuenca‐Estrella & C Lass‐FlörlEUCAST AFST SC: Arendrup (chair), Howard (secretary), Meletiadis (data manager), Mouton, Cuenca‐Estrella, Lass‐Flörl

Antifungal breakpoints and susceptibility testing

Dr Susan J Howard

Manchester, UK

Scientific Secretary

EUCAST Antifungal Steering Committee




Disclosures ‐ none




Agenda

• Setting the scene

• Methodology outline

• ECOFF/breakpoint setting

• Current guidelines




Agenda







Background

• The mortality rate associated with fungal disease is dire

• Susceptibility is just one factor affecting outcome

• Limited therapeutic drug class options

• Global antifungal drug budget is significant (est. $US 5.7 billion in 2014)



Why Susceptibility Test?

• Intrinsic resistance

• Acquired resistance (increasing in some

settings)

• Some identifications challenging/slow

• Historically multiple/differing

methodologies, with no/limited breakpoints

to allow comparison/interpretation




Agenda







Methodology

• Commercially available tests

– Including disc diffusion, Sensititre, Vitek and Etest

• Broth dilution reference methods

– CLSI & EUCAST



EUCAST Method

P NDrug dilutions

• Flat bottom plates

• RPMI with 2% glucose and MOPS

• Incubate at 35 ± 2˚C




YeastsFermentative yeasts E.DEF 7.2 (2012)

– 0.5‐2.5 x 105 cells/mL

– 24 h and OD ≥ 0.2

– Spectrophotometer

– 90% endpoint (AMB) / 50% endpoint (all others)



MouldsConidia forming moulds E.DEF 9.2 (2014)

– 1‐2.5 x 105 cells/mL

(avoid clumps)

– 48 h adequate growth*

(*24h may be sufficient for

some zygomycetes,

some moulds require 72h)

– Visual endpoint reading

amphotericin & azoles =

no growth endpoint (MIC)

echinocandins =

aberrant growth (MEC)

CntFlu16‐0.125

Vor Itra4‐0.03

Amb Casp8‐0.06

MIC/MEC 0.5 ≤0.06 0.5 0.5 >16



MEC Aspergillus

Growth control Aberrant growth




Agenda







ECOFFs versus Breakpoints

Epidemiological cut off value (ECOFFs)

– Based on the wild‐type MIC distributions– Upper limit of WT isolates – Typically describes isolates with identical susceptibility

– Typically describes isolates with no resistance mechanisms

Clinical breakpoints

– Take other factors (e.g. PK/PD and clinical data) into account

– More later…



http://mic.eucast.org/Eucast2/

ECOFF:

≤32 µg/ml

MIC50

WTpopulation

Non‐WT

• May or may not respond depending on host & drug exposure

• Harbour resistance mechanisms

EUCAST fluconazole MIC C. glabrata




Wild‐type MIC Distributions34 different C. glabrata isolates

Arendrup AAC 2009

‐25

‐20

‐15

‐10

‐5

0

5

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15

20

0.25 0.5 1 2 4 8 16 >16

No. of isolates

MIC (µg/ml)



Wild‐type MIC Distributions34 different C. glabrata isolates

Arendrup AAC 2009

‐25

‐20

‐15

‐10

‐5

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No. of isolates

MIC (µg/ml)

A single C. glabrata isolate tested 51 times



Variability in Wild‐type Distributions

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Reflects the inherent susceptibility of the WT population

Arendrup AAC 2009




Caspofungin and Variability (EUCAST)

No. of C. albicans isolates at the individual EUCAST MICs (mg/L) No.

Tested0.002 0.004 0.007 0.015 0.03 0.06 0.12 0.25 0.5 1 2 ≥ 4

CFG

Lab 1 ND ND ND 20 30 35 45 130

Lab 2 ND ND ND ND ND 123 162 209 102 9 1 606

Lab 3 ND ND ND ND ND 10 161 219 8 5 1 404

Lab 4 ND ND ND 2 105 264 182 54 11 3 1 4 626

Lab 5 ND ND 6 12 12 5 3 38

Lab 6 ND ND ND ND 25 5 1 31

Lab 7 ND ND ND ND 1 2 14 330 373 1 721

MFG

Lab 1 ND ND ND ND 107 107

Lab 2 ND 121 2 123

Lab 3 ND 34 19 12 30 4 1 100

Lab 4 ND 78 19 2 1 100

Lab 5 ND ND ND 520 35 2 1 2 560

Lab 6 4 87 252 239 4 4 590

Lab 7 ND ND 87 2 89

EUCAST MIC50 is highlighted

Considerable variation for caspofungin

EUCAST abstained from setting cut offs

Espinel‐Ingroff AAC 2013, Arendrup Mycoses in press



Population with WT and non‐WT

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C. glabrata repetitions

One step lower

Non‐WTwith MIC50 64 µg/ml(4 steps higher)

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Real Life Breakpoint ExampleA. fumigatus

Itraconazole

Clear separation WT and non‐WT

Verweij Drug Res Updates 2009

Posaconazole

Overlap WT and non‐WT further analysis needed to identify all non‐WT




EUCAST BP Setting Process

• MIC distributions

– Per species

– Several data sets

– Epidemiological Cut Off Value (ECOFF)

• Dosing regimens used

• PK/PD

• MIC‐clinical outcome relationships

– Per species

– For wild type and non‐wild type isolates

Arendrup Drug Res Updates 2014



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140

0.002

0.004

0.008

0.016

0.032

0.064

0.125

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32

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512

Isolates

MIC

C. krusei

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C. glabrata

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Isolates

C. albicans

ECOFF versus Breakpoint (flucon)

www.eucast.org

C. albicans BP (S: ≤x ; R: >y) ECOFF 1 mg/L ≤2 mg/L ; >4 mg/L

C. glabrata BPECOFF 32 mg/L ≤0.002 mg/L ; >32 mg/L

C. krusei BPECOFF 128 mg/L none – not a good target



Agenda








Website

www.eucast.org



ECOFF/Breakpoint Updates

• Recent updates (since ECCMID 2014):

– Mould E.DEF 9.2 definitive document

– Itraconazole Candida rationale document

– BP table (itra Candida BP added, caspo BP comment revised)

• Forthcoming documents to look out for in 2015:

– Amphotericin Candida rationale document

– Posaconazole Candida rationale document

– Voriconazole Candida rationale document

– Isavuconazole Aspergillus rationale document



Thank you for your attention

Acknowledgements

The EUCAST Steering Committee Maiken ArendrupJoseph MeletiadisJohan MoutonManuel Cuenca‐EstrellaCornelia Lass‐Flörl

The EUCAST General (Sub) Committee

Strumbelj ‐ National introduction of EUCAST breakpoints and methods

1

Iztok Štrumbelj

• National Laboratory of Health, Environment and Food

Maribor, Slovenia

National introduction of EUCASTbreakpoints and methods

• Slovenian National Antimicrobial Susceptibility Testing Committee

2

Disclosure.

Iztok Štrumbelj: no conflict of interest, nothing to disclose.

3

Slovenia• Population: 2 million • Independent since 1991

http://www.slovenia.info/

Purpose:to describe the introduction of European Committee on Antimicrobial Susceptibility Testing (EUCAST) bacteriology breakpoints and methods in Slovenia.

http://www.itis.si/zemljevid


4

Hospitals in Slovenia

29 hospitals (26 public, 3 private), most samples from:

• 2 university clinical centres• 11 general hospitals

Source: Zdravstveni statistični letopis 2012, Nacionalni inštitut za javno zdravje (NIJZ).

Medical microbiology laboratories are parts of different public institutions

• 1 university laboratory (Institute of Microbiology and Immunology, Faculty of Medicine, University of Ljubljana)

• 8 laboratories are departments of Centre for Medical Microbiology of National Laboratory of Health, Environment and Food

• 3 are hospital laboratories

5

Certified medical microbiology laboratories in Slovenia

Quality system (QS) and certification of diagnostic laboratories1. Quality system (QS), published in Official Gazette of Republic of Slovenia2. Audit of laboratory QS by independent Commission3. If requirements met: “permission to work” issued by Ministry of Health for 5

years.

List of certified diagnostic laboratories in the field of clinical bacteriology published at the website of Ministry of Health. (accessed March 19th, 2015)

12 laboratories:‐ 1 specialised in mycobacteriology‐ 11 perform antimicrobial susceptibility testing of common bacteria

6

Slovenian National Antimicrobial Susceptibility Testing Committee Slovenian acronym: SKUOPZSlovenska komisija za ugotavljanje občutljivosti za protimikrobna zdravila

• Established: at the end of 2010.• Members: at least one member from each certified laboratory and one

member from National Institute of Public Health

• Two working areas:

a) Methods for antimicrobial susceptibility testing (AST)b) Surveillance of antimicrobial resistance (AMR) ‐ three annual national reports

were published on web (2011, 2012, 2013).


http://www.imi.si/strokovna‐zdruzenja/skuopz

Example page from SKUOPZ annual national report

8

Antimicrobial susceptiblity testing (AST)methods used in Slovenia

Disk diffusion method used as principal method.

For MIC determination, gradient diffusion method is mostly used. Always for anaerobes.

Standard microdilution method not used routinely.

Automated AST systems used in few laboratories.

Both, MICs and zones, entered and interpreted in LIS.

9

Transition from CLSI to EUCAST

Introduction, June 2013

• EUCAST presented in ISIS – official journal of Slovenian Medical Chamber• Symposium about EUCAST for microbiologists and clinicians

The process, June 2013 – April 2014

Three main points• Laboratory information system (LIS) upgrade. • Laboratory methods. • Information for clinicians.

Final control• Results of external quality assessment.‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐

Note: in this presentation, “agent” means “antimicrobial agent”.


10

Introduction, June 2013. EUCAST presented in ISIS – official journal of Slovenian Medical Chamber.Symposium with international speakers for microbiologists and clinicians, round table. Final unanimous decision: EUCAST should be introduced.

12

Consensus

During the whole process of EUCAST implementation – all decisions of SKUOPZ were accepted by consensus.

The first major decision was critical.

• Request of some clinicians: to supplement EUCAST breakpoints with breakpoints from other AST systems, if EUCAST has no breakpoint for an agent / species (e.g. ampicilin‐sulbactam and Acinetobacter baumannii)

• SKUOPZ decision: unacceptable. “Mixing” breakpoints would lead to a confusion.

Strict use of EUCAST interpretations was followed:

(‐) dash in the EUCAST breakpoint tables: no testing or resistant result.(IE) insufficient evidence in the breakpoint tables: if necessary (rarely) MIC

can be determined, but without interpretation into SIR category.


13

Laboratory information system (LIS) upgrade (1)

Review of processes:

Identification of need: what do we want from LIS (responsibility of SKUOPZ)

Dedicated clinical microbiologist and software expert Alenka Štorman communicatedthe need for changes to software provider who finally implemented all software changes.

Alenka Štorman personally performed amazing amount of extensive and difficult tasks:

entered all breakpoint values (MICs and zones) into LIS wrote all comments (prepared by SKUOPZ) into LIS linked them to the proper AST result for different species / agents validated LIS after changes were implemented.

14


All laboratories use the same LIS provided by a Slovenian software company. The software development was started by Jana Kolman, MD and Alenka Štorman, MD, clinical microbiologists, in mid‐nineties.

INTERPRETATION OF ZONES AND MICs (into S, I, R category).

Background: it is not rare that one MIC / disk zone is interpreted differently for different species or that interpretation of MIC /zone is limited only to few species within bacterial group.

Automatic interpretation of MICs / zones, linked to different species, makes life easier.

Result of upgrade: all zones (calliper is used) and MICs are entered into LIS, where automatically interpreted as S, I or R.

Very rarely, manual correction of the result is necessary.

LIS precludes S, I, R interpretation if there are no EUCAST breakpoints.

15


COMMENTS OF RESULTS appearing on the results form

Background: for proper interpretation of many EUCAST results (S, I or R), comments are common and essential.

Basic idea: to make comments as user friendly as possible for laboratories (automatic link of the comment with the specific result of an agent) and clinicians (as short and as clear as possible).

Considerable amount of work and discussions was necessary to integrate (or split)guidelines and rules from different EUCAST documents into software rules so thatcomments are added to laboratory reports automatically ‐ 99 different comments were entered into LIS.

Result of LIS upgrade: comments are linked to the results so that appropriate comment is automatically linked to the agent or agent result.


16

Breakpoints may be different for different species within a group

Species specific breakpoints within a group.

Software precludes use of inappropriate breakpoints for the species tested.

Example: Staphylococcus spp. ‐ breakpoints for cefoxitin screen disk (surrogate disk for “methicillin “ susceptibility / resistance)

Species Zone – methicilin susceptible

S. aureus, S. lugdunensis and S. saprophyticus

S ≥ 22

S. pseudintermedius S ≥ 35

Other coagulase‐negative staphylococci S ≥ 25

17

Breakpoints may be limited to some species within a group

There is no interpretation (no breakpoints) for other species in the group.

Software precludes interpretation for species without breakpoints.

Example 1. Systemic infections.

Example 2. Uncomplicated urinary tract infections only.

Group Agent Breakpoints limited to

Enterobacteriaceae Cefuroxime iv E. coli, Klebsiella spp. andP. mirabilis

Group Agent Breakpoints limited to

Enterobacteriaceae Nitrofurantoin E. coli

Enterococcus spp. Nitrofurantoin E. faecalis

Staphylococcus spp. Nitrofurantoin S. saprophyticus

Streptococcus spp. Nitrofurantoin S. agalactiae

18

Manual correction of results

Example 1. Staphylococcus spp., inducible clindamycin resistance.

Example 2. Staphylococcus aureus, penicillin.

Agent, disk “Zone test result” Reason for change

Final result forthe agent

Clindamycin Zone ≥ 22 mm, S – susceptible.

Positive D‐phenomenon.

R ‐ resistant

Agent, disk “Zone test result” Reason for change

Final result forthe agent

Penicillin Zone ≥ 26 mm, S ‐ susceptible

The zone edge is sharp.

R ‐ resistant


19

Comments / notes in the report

• Few comments are added manually, e.g. when resistance mechanism is determined.

• Most of comments appear automatically ‐ they are linked to an element. “Element” is isolate and:

1. the agent or2. result of the agent or3. MIC of the agent.

• Comment may be a translation of EUCAST note or synthesis of several data from EUCAST documents (e.g. several notes in breakpoint tables).

• One comment may be used for several different elements.

20

Comments linked to the agent

Applicability of the result of an agent to other agents

• Isolate: Staphylococcus spp. Agent: erythromycin• Comment: Result of erythromycin applies also to azithromycin,

clarithromycin and roxithromycin.

• Isolate: Streptococcus agalactiae. Agent: penicillin.• Comment: Streptococcus agalactiae ‐ result of penicillin applies also to

other penicillins (with the exception of phenoxymethylpenicillin and isoxazolylpenicillins), to cephalosporins (with the exception of cefiximeand ceftazidime) and to carbapenemes.

Explanation about the agent tested

• Isolate from urine: Enterococcus spp. Agent: norfloksacin disk is tested.• Comment: Enterococcus ‐ result of norfloksacin disk is valid for

ciprofloxacin and levofloxacin, not for norfloxacin. Result applies to uncomplicated urinary tract infections only.

21

Comments linked to the dose of an agent

General comment about high dose.• Isolate: Pseudomonas spp. • Agent: ceftazidime• Comment: Result applies to high dose therapy.

Specific once‐daily application of high daily dose.• Isolate: Pseudomonas spp. • Agent: gentamicin.• Comment: Result applies to once‐daily administration of high

aminoglycoside dosages.

Specific dose of an agent for the isolate; comment may be specific for S or I result.

• Isolate: isolate without species specific breakpoint, PK/PD breakpoints used.

• Agent: imipenem.• Comment: Breakpoints apply to imipenem 500 mg x 4 daily administered

intravenously over 30 minutes as the lowest dose. 1 g x 4 daily was taken into consideration for severe infections and in setting the R breakpoint.


22

Comments linked to the SIR result of an agent Agent : methicillin (tested with cefoxitin disk, reported as oxacillin result).

Isolate: any staphylococcus. Result: S.Comment: Oxacillin susceptible staphylococcal isolate is also susceptible to

other antistaphyloccal penicillins (e.g. cloxacillin, flucloxacillin), to penicillins with betalactamase inhibitors, to carbapenemes and to cephalosporins ‐ except for ceftazidime, cefixime and ceftibuten, which should not be used for staphylococcal infections.

Isolate: Stapylococcus aureus *Result: R.Comment: Stapylococcus aureus, resistant to oxacillin, is resistant to all beta‐

lactam agents; exceptions are ceftaroline and ceftobiprole if their antimicrobial susceptibility result is susceptibility (S).

* Note: Comments for CNS are slightly different ‐ no ceftaroline and ceftobiprole breakpoint.

23

Comments linked to the MIC of an agent

Isolate: Streptococcus pneumoniae. Comments relate to treatment of pneumonia.

Result and comment for parenteral penicillin, non‐meningeal criteria:

24

Sources.

Links to following »basic« documents are provided on the EUCAST web sitehttp://www.eucast.org (current versions, accessed 25th March 2015).

General information at: http://www.eucast.org•The European Committee on Antimicrobial Susceptibility Testing. Breakpoint tables for interpretation of MICs and zone diameters. Version 5.0, 2015. •Leclercq R et al. EUCAST expert rules in antimicrobial susceptibility testing (2011)•Giske CG et al. EUCAST guidelines for detection of resistance mechanisms and specific resistances of clinical and/or epidemiological importance. (Version 1.0. December 2013)•Guidance Document on Stenotrophomonas maltophilia (1 Feb 2012)•Guidance Document on Burkholderia cepacia group (20 July, 2013)•Guidance Document on Breakpoints for topical use of antimicrobial agents (2014)•Check list to facilitate implementation of antimicrobial susceptibility testing with EUCAST breakpoints (2010)•EUCAST QC table v 5.0 (2015‐01‐11)•Preparation of plates and media for EUCAST AST (v 4.0, 19 June, 2014) •Compliance of manufacturers of susceptibility testing devices and materials (25 September, 2014)


25

Disk‐diffusion documents at: http://www.eucast.org(current versions, accessed 25th March 2015).•EUCAST Disk Diffusion ‐Manual (v 5.0, 26 January, 2015)•EUCAST Disk Diffusion ‐ Slide Show (v 5.0, 26 January, 2015)•EUCAST Disk Diffusion ‐ Reading Guide (v. 4.0, 19 June, 2014)•Matuschek E et al. Development of the EUCAST disk diffusion antimicrobial susceptibility testing method and its implementation in routine microbiology laboratories. (2014)

Whenever a clear answer can’t be found in other documents, solution can be frequently found following the link:•Frequently Asked Questions (2015‐03‐23)

Whenever this option failed, we sent an E‐mail to Erika Matuschek, Clinical Scientist, responsible for the EUCAST Development Laboratory, Växjö, Sweden.Answers were extremely fast and helpful. Thanks!

Implementation of EUCAST – laboratory work

• Basic guide: this "check list".

• "General issues" were discussed by SKUOPZ

• Practical work was done in each laboratory

• SKUOPZ member was "a champion among laboratory staff" in each laboratory – i.e. responsible for the process

• About 6 months of work was necessary before Quality Control results were fully compliant and EUCAST implemented.

26

27

Laboratory methods ‐ training.

A lot of practice and “tuning” of procedures and staff was needed, most difficult parts were:

• searching for suitable MHF agar (home made or ready to use plates)

• proper inoculum preparation, inoculation and reading of MHFplates.

Practical advice (provided by E. Matuschek):‐ When inoculating haemophilus, plates must be sufficiently dry and

swabs before inoculation extremely dry.

Procedures on Mueller Hinton were technically relatively simple,EUCAST disk diffusion reading guide and slide show very useful, however, considerable amount of time still needed for details.


28

Laboratory methods ‐materials

Some new quality control strains.

‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐

Disk‐diffusion method• Some disks have different contents in CLSI and EUCAST. • New agar: Mueller Hinton Fastidious agar.

‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐MIC determination

Note: • SKUOPZ policy: use of commercial methods (including gradient

diffusion) is the responsibility of each laboratory.Essential requirement – MIC materials (machines and consumables

must be according to EUCAST).

29

Laboratory methods – materials, MICs

For EUCAST susceptibility testing purposes, the concentration of sulbactamis fixed at 4 mg/L, of clavulanic acid is fixed at 2 mg/L, of tazobactam is fixed at 4 mg/L.

Optimally, range of MIC values should be suitable for different purposes. Example: Enterobacteriaceae, meropenem

Purpose Lower MIC Higher MIC

Clinical breakpoints S ≤ 2 mg/L R > 8 mg/L

Screening for carbapenemase Negative screen≤ 0.12 mg/L

Positive screen> 0.12 mg/L

EUCAST quality control rangeEscherichia coli ATCC 25922

Minimum0.008

Maximum0.06

30

Detailed Slovenian guidelines for Enterobacteriaceae –

ESBL, AmpC and carbapenemases.

Guideline 001: Carbapenem resistance,Enterobacteriaceae.

Guideline 002: ESBL, AmpC,Enterobacteriaceae.


31

Slovenian guidelines for carbapenemase ‐producing Enterobacteriaceae .

Fully compliant with “EUCAST guidelines for detection of resistance mechanisms and specific resistances of clinical and/or epidemiological importance”, Version 1.0, December 2013. Details were specified, epidemiological definitions for CRE and CRE‐CPE were added.

Screening cut –off:

‐ EUCAST guideline offers two possibilities for meropenem disk screening cut‐off. <25 mm (“best balance of sensitivity and specificity”)<27 mm (“may be used as a screening cut‐off in countries where OXA‐48 is endemic, but at the expense of lower specificity”).

‐meropenem cut‐off < 27 mm was chosen(other combinations of carbapenems can be used)

Phenotypic methods for detection of carbapenemases:

Two methods with different mechanisms are used for each “suspicious” isolate:‐ Carbapenem hydrolisis test (Carba NP test or Blue‐Carba).‐ Combined disks (tablets) with carbapenemase inhibitors (including “triple “ disk + temocillin + cloxacillin)

32

Information for clinicians.

April 2014. Transition to EUCAST implemented.When possible, personal contacts with clinicians were used.

One page long information about EUCAST, supplemented with table of major differences between CLSI and EUCAST, was distributed to users when we changed to EUCAST.

This information included link to SKUOPZ web home page, where concise but quite comprehensive information (15 pages) for clinicians were published:“Short explanation on transition to EUCAST “(in Slovene)

Every day on each report.Comments available when needed.

http://www.imi.si/strokovna‐zdruzenja/skuopz

33

“Short explanation on transition to EUCAST”


34

Results of the process

April 2014: all but one diagnostic medical microbiology laboratories in Slovenia implemented EUCAST.

Results of external quality assessment (EQA)

All SKUOPZ laboratories that have implemented EUCAST were asked to report all scored results of EQA since April 2014 to the end of 2014.

Cumulative results for 1154 bacteria/antibiotic results:

• Categorical agreement: 1149 (99,6 %)• Major discrepancy: 4 (0,3%)• Very major discrepancy: 1 (0,1%)

35

Conclusions

Introduction of EUCAST was a demanding national project:

• coordinated by the national AST committee – SKUOPZ• activities “at the bench” were performed by each

laboratory.

Three key points were:

• Changes in laboratory information system • Changes in laboratory methods• Information for clinicians.

System was well accepted by both laboratories and clinicians.

36

Acknowledgments

EUCAST Secretariat, EUCAST Development Laboratory and speakers at EUCAST symposium in LjubljanaRafael Cantón, Derek Brown, Gunnar Kahlmeter, Erika Matuschek, ArjanaTambić Andrašević, Iva Butić, Katja Seme

SKUOPZ membersIngrid Berce, Jerneja Fišer, Andrej Golle, Tatjana Harlander, Martina Kavčič, Jana Kolman, Slavica Lorenčič‐Robnik, Tadeja Matos, Verica Mioč, Manica Mueller‐Premru, Irena Piltaver‐Vajdec, Mateja Pirš, Katja Seme, Helena Ribič, Alenka Štorman, Viktorija Tomič, Barbara Zdolšek, MancaŽolnir Dovč.

Laboratory staff of Slovenian clinical microbiology laboratories

Review of this presentationKatja Seme, Mateja Pirš, Jernej Štrumbelj

Brown ‐ Clindamycin susceptibility testing and reporting

Clindamycin susceptibility testing and reporting

Derek Brown EUCAST Scientific Secretary

EUCAST Educational Workshop, ECCMID 2015

Clindamycin

• Lincosamide agent classified in the macrolide, lincosamide and streptogramin group

• Used to treat staphylococcal and streptococcal skin and soft tissue infections, particularly in general practice and outpatients

Clindamycin resistance mechanisms in staphylococci and streptococci

• Most resistance to macrolide, lincosamide and streptogramin type B (MLSB) antimicrobial agents is mediated by the erm genes (ribosomal methylation) and is induced by erythromycin, clarithromycin and azithromycin, but not by clindamycin (dissociated resistance or MLSB inducible resistance).

• Strains with MLSB constitutive resistance are resistant to clindamycin.

• Efflux

• Ribosomal mutation


Clindamycin MIC distribution for S. aureus

RS

Clindamycin MIC distribution for coagulase-negative staphylococci

RS

Clindamycin MIC distribution for Streptococcus pyogenes

S R


Clindamycin MIC distribution for Streptococcus agalactiae

S R

Detection of inducible clindamycin resistance in staphylococci and streptococci by disk diffusion

• Disk diffusion –the “D test”

• Erythromycin 15 µg and clindamycin 2 µg disks placed 12-20 mm apart (edge to edge) for staphylococci, 12-16 mm apart for streptococci

• “Antagonism” of clindamycin by erythromycin indicates inducible resistance

Detection of inducible clindamycin resistance in staphylococci and

streptococci by broth microdilution

• Test clindamycin MIC in presence of fixed concentration of erythromycin– Staphylococci 4 mg/L erythromycin– Streptococci 1 mg/L erythromycin

• Staphylococci– Clindamycin MIC >0.25 mg/L in presence of erythromycin

and ≤0.25 mg/L without erythromycin indicates inducible resistance (Swenson et al, JCM, 2007)

• Streptococci– Clindamycin MIC >0.5 mg/L in presence of erythromycin

and ≤0.5 mg/L without erythromycin indicates inducible resistance (Bowling et al, JCM, 2010)


Detection of inducible clindamycin resistance in staphylococci by

automated systems

• Vitek 2 (Sensitivity 80-95%)– Bobenchik et al, JCM 2014. Inducible R detected in 24/30 isolates

– Gardiner et al, Pathology 2013. Inducible R detected in 191/201 isolates

– Lavallee et al, JCM 2010. Inducible R detected in 124/134 isolates

– Buchan et al, DMID 2012. Inducible R detected in 51/56 isolates

• Phoenix– Buchan et al, DMID 2012. Inducible R detected in 56/56 isolates

• Microscan– Ji et al, Korean J Lab Med 2010. Inducible R detected in 58/58 isolates

Detection of inducible clindamycin resistance in streptococci by

automated systems

• Vitek 2 (Sensitivity 36-95%)– Tazi et al, JAC 2007. Inducible R detected in 9/25 of Group B isolates

– Tang et al, JCM 2004. Inducible R detected in 17/18 of Group B isolates

• Phoenix

– Buchan et al, DMID 2012. Inducible R detected in 100% of Group B isolates (not clear how many tested)

– Richter et al, JCM 2007 Inducible R detected in 23/23 of Group B isolates

Reporting inducible clindamycin resistance in staphylococci and

streptococci• Should staphylococci and streptococci with

inducible clindamycin resistance be reported resistant or susceptible?

• Inducible strains segregate clindamycin resistant mutants, which may be selected during treatment, possibly leading to treatment failure


Reporting inducible clindamycin resistance in staphylococci and

streptococci• Guidance on reporting has been inconsistent

Susceptible with warning that resistance may develop during treatment

OR

Resistant with note that less serious infections may still be treatable

EARSNet External Quality AssessmentS. aureus with inducible clindamycin resistance

(MIC 0.12 mg/L, but resistance induced by erythromycin)

• Reports from participants

•

• Reports of susceptible not related to guideline or method

• Different recommendations from EUCAST and CLSI

– EUCAST expert rules recommend reporting resistant, or susceptible with warning of possible failure due to selection of resistant mutants. Avoid use in serious infections

– CLSI report resistant with note that some may respond

Specimen NPercent reporting

S I R

0275 (2011) 775 24.0 1.8 74.2

1377 (2012) 705 7.5 1.4 91.1

Evidence for clinical significance of inducible resistance to clindamycin in staphylococci and streptococci?

• In vitro studies

• Animal models

• Clinical outcome data


In vitro studies (S. aureus)

• Constitutive resistant mutants can be selected by culture in the presence of clindamycin.

Panagea et al. JAC 1999: 44; 581-2

Daurel et al. JCM 2008: 46; 546-55

• Time-kill studies indicate initial killing but rapid regrowth

Leplante et al. AAC 2008: 52; 2156-62

Animal models of infection with MLSBi S. aureus

• Mouse thigh model with low inoculum (105) – Clindamycin reduced CFU by 0.45 and1.3 logs for

two isolates at 72h.

– Constitutive resistant mutants detected at 72h.

• Mouse thigh model with high inoculum (107) – Clindamycin showed bacteriostatic activity at 24h and

growth of 0.39 and 1.28 logs for two isolates at 72h.

– Constitutive resistant mutants detected at 24h.

Leplante et al. AAC 2008: 52; 2156-62

Animal models of infection with MLSBi streptococci

• Neutropenic mouse thigh model with inoculum (107) – Clindamycin reduced CFU over 12h for two isolates

(one Group A and one Group B) but then regrowth to similar level to constitutive resistant isolates by 72h.

Lewis et al. AAC 2014: 58; 1327-31


Issues in assessing clinical data on significance of MLSBi resistance

• Anecdotal cases of failures more likely to be reported than successes

• Non-severe cases may have spontaneous favourable outcome

• Initial treatment often with a β-lactam agent or vancomycin, the clindamycin

• Treatment of non-severe cases in general practice or as outpatients so often no follow up unless treatment fails

• Contribution of treatment when there is surgical intervention is unclear

Clinical data on outcome of infection with MLSBi S. aureus

Reference No. of patients

Outcome Susceptibility

McGehee et al. AAC 1968:13;392

3 2 failed1 success

2 S pre-treatment3 R post-treatmentNot tested for MLSBi

Drinkovic et al. JAC 2001:48:315

3 1 failed2 success

1 MLSBc

Frank . Ped Inf Dis J 2002:21;530

10 2 failed 1 MLSBc

Rao. JAC 2000:45;715 3 1 failed2 success

1 MLSBc

Watanakunacorn. Am J Med 1976:60;419

1 1 failed 1 S pre-treatment1 R post-treatmentNot tested for MLSBi

Siberry et al.Clin Inf Dis 2003:37;1257

1 1 failed 1 MLSBc

Clinical data on outcome of infection with MLSBi streptococci

Reference No. of patients

Outcome Post therapy susceptibility

Lewis et al.AAC 2014:58;1327

8 with Gp B 8 failed


Inducible clindamycin resistance in staphylococci and streptococci• There is a significant risk of failure of therapy in

treatment of more severe infections

• There is not strong evidence relating to treatment of less serious infections

• EUCAST guidelines for staphylococci and streptococci in breakpoint tables v. 5.0 2015

If MLSBi detected, then report as resistant

Consider adding this comment to the report:"Clindamycin may still be used for short-term therapy of less serious skin and soft tissue infections as constitutive resistance is unlikely to develop during such therapy".

Gatermann, Expert Rules ECCMID 2015

Expert rules in antimicrobial susceptibility testing

Sören Gatermann Bochum, Germany

[email protected]

Objectives

● improve therapeutic relevance of susceptibility testing results

● recognition of the unusual● should have consequences

● therapy● infection control

● satisfy curiosity

Recognition of the unusual

● natural resistance● e.g. clindamycin or cefalosporins in enterococci

● typical susceptibility● penicillin in ß-haemolytic streptococci● carbapenems in enterobacteria

– in some places rare in others frequent

Gatermann, Expert Rules ECCMID 2015

Improve therapeutic relevance

● staphylococci● cefoxitin/oxacillin predicts utility of ß-lactams● D-phenomenom predicts utility of clindamycin

● enterobacteria● carbapenemases● ESBL● AmpC

Improve therapeutic relevance

● pneumococci● in pneumonia● in meningits

● H. influenzae● detect ß-Lactamase● BLNAR

Jones ‐ Susceptibility testing of new and revived antimicrobial agents

Susceptibility Testing of New and Revived Antimicrobial AgentsSusceptibility Testing of New and Revived Antimicrobial Agents

Ronald N. Jones, MD, FAAM, FASCP, FCAP, FIDSA*JMI Laboratories

North Liberty, Iowa

USA

1*Scientific Secretary of the

US Committee on Antimicrobial Susceptibility Testing (USCAST)

Disclosure and Transparency StatementDisclosure and Transparency Statement

JMI Laboratories, Inc., received additional research and educational

grants in 2012 to 2014 from Achaogen, Actelion, Affinium, American

Proficiency Institute (API), AmpliPhi Bio, Anacor, Astellas, AstraZeneca,

Basilea, BioVersys, Cardeas, Cempra, Cerexa, Daiichi, Dipexium, Durata,

Fedora, Forest Research Institute, Furiex, Genentech, GlaxoSmithKline,

Janssen, Johnson & Johnson, Medpace, Meiji Seika Kaisha, Melinta,

Merck, MethylGene, Nabriva, Nanosphere, Novartis, Pfizer, Polyphor,

Rempex, Roche, Seachaid, Shionogi, Synthes, The Medicines Co., Theravance,Thermo Fisher Scientific, VenatoRx, Vertex, Waterloo, and some other corporations. Some JMI employees are advisors/consultants for Astellas,Cubist Pharmaceuticals, Pfizer, Cempra, Cerexa‐Forest, and Theravance.

2

Presentation OutlinePresentation Outline

1. Background of typical AST development

2. Contemporary challenges to AST development

‐ New agents (lipoglycopeptides, oxazolidinones) with specific technical issues

‐ Revived older agents or combinations

3. Integrating AST challenges with emerging understanding of drug exposure (PK/PD) optimization

4. Conclusions

3


Background of AST Development (“The Past”)Background of AST Development (“The Past”)

1. Mode of actions, breadth of spectrum, and cidality

2. MIC distributions and establishing the treatable wildtype (WT) distribution

3. Pharmacokinetics (dosing ranges)4. Establishing reference method (broth or agar)

and required supplements5. Standardizing disk test correlate testing details6. Assigning clinical breakpoints driven by Phase 3

trial response rates

4

Background of AST Development (“Now”)Background of AST Development (“Now”)

1. Mode of actions, breadth of spectrum, and cidality2. MIC distributions and establishing the treatable wildtype

(WT) distribution3. Pharmacokinetics (dosing ranges), with greater emphasis

on pharmacodynamics.4. Establishing reference method (broth or agar) and

required supplements, with greater technical challenges of media quality, supplements and method variations.

5. Standardizing disk test correlate testing details, but drug disk contents may differ by geographic region or the diffusion methods may be compromised.

6. Assigning clinical breakpoints driven by Phase 3 trial response rates, but pharmacodynamic modeling and TA data have become very helpful.

5

Examples of Recent AST Development and Breakpoint IssuesExamples of Recent AST Development and Breakpoint Issues

• Lipoglycopeptide development, a long painful history – Dalbavancin*– Oritavancin*– Telavancin*

• Oxazolidinones– Linezolid– Tedizolid*

• Combination drugs– Ceftazidime‐Avibactam (CAZ‐AVI)*– Ceftolozane‐Tazobactam (TOL‐TAZ)*

• Polymyxins among other agents– Colistin and Polymyxin B

*Six new drug breakpoints evaluated in the last yearA1


Glycopeptides(Vancomycin, Teicoplanin)

Lipoglycopeptides(Dalbavancin, Oritavancin, Telavancin)

Greater potency Heavy molecular weight

Extended serum elimination half‐life Less soluble

“Sticky”

A2

Structure of DalbavancinStructure of Dalbavancin

A3

Dalbavancin Activity Trends from Key PublicationsaDalbavancin Activity Trends from Key Publicationsa

A4

MIC50/MIC90 (% >0.12 µg/ml)a

Pathogen Jones (1999‐2000) Biedenbach (2002‐2007) Jones (2012)

Staphylococci

S. aureus (no.) (155)0.12/0.25 (45)

(46,773)0.06/0.06 (1)

(1,000)0.06/0.06 (<1)

CoNS (no.) (67)0.12/0.25 (30)

(12,308)≤0.03/0.06 (1)

(122)0.06/0.06 (<1)

a. From Jones et. al. J. Chemother. 2001; 13: 244-254, and Biedenbach et. al. Antimicrob. Agents Chemother. 2009; 53: 1260-1263, and Jones et. al. Diagn. Microbiol. Inf. Dis. 2013; 76: 122-124.


FIG 1. Influence of various P-80 concentrations (0.000002 to 2%) on the dalbavancin MIC results for S. aureus (11 strains) and beta-hemolytic streptococci (4 strains)

FIG 1. Influence of various P-80 concentrations (0.000002 to 2%) on the dalbavancin MIC results for S. aureus (11 strains) and beta-hemolytic streptococci (4 strains)

A5*From Rennie et. al. J. Clin. Microbiol. 2007; 45: 3151‐3154

Dry-form MIC Panel Validation (Sensititre®)*Dry-form MIC Panel Validation (Sensititre®)*

A6

*From Jones et. al. Int. J. Antimicrob. Agents 2004; 23:197‐199.

Surrogate Testing (2006)Surrogate Testing (2006)

A7*From Jones et. al. J. Clin. Microbiol. 2006; 44: 2622‐2625.

99.8%predictive


Surrogate TestingSurrogate Testing

A8

4

2

1

0.5 4 1

0.25 1 1 32 10

0.12 2 195 2895 119

0.06 5 3193 17946 325

0.03 1 36 2888 6000 34

0.12 0.25 0.5 1 2 4 8 16

Dalbavancin M

IC (µg/ml)

Vancomycin MIC (µg/ml)

Figure 1. S. aureus (33,688 strains) isolated from the USA and Europe in 2011-2013a.

a. Broken horizontal line shows USA-FDA breakpoint (≤0.12 µg/ml) having acceptable predictive values (99.9%); and the solid vertical line is the vancomycin breakpoint.

*From Jones et. al. (in press)

Surrogate TestingSurrogate Testing

A9

Pathogen or species group (no. tested)Surrogate accuracy for breakpoint at:

≤0.12 ≤0.25

S. aureus (33,688) 99.86a 99.99

β‐haemolytic streptococci (5,722) 98.97 100.00

S. pyogenes (2,297) 100.00a 100.00

S. agalactiae (2,495) 97.72a 100.00

Viridans group streptococci (2,800) 100.00 100.00

S. anginosus group (758) 100.00a 100.00

CoNS (4,576) 97.55 99.87

Enterococci (6,515) 98.43 99.94

Table 2. Summary of vancomycin test result accuracy for predicting dalbavancin susceptibility using two breakpoint concentrations (≤0.12 and ≤0.25 µg/ml) when tested against eight Gram-positive pathogen/groups in 2011-2013.

a. Underlined percentage shows USA-FDA approved breakpoint for clinical use versus indicated species/groups.

*From Jones et. al. (in press)

Oritavancin MIC results (across 14 years)Oritavancin MIC results (across 14 years)

Nicas et al., AAC, 1996Schwalbe et al., AAC, 1996Jones et al., AAC, 1996Biavasco et al., AAC, 1997

Zeckelet al., AAC, 2000Noviello et al., JAC, 2001Arhin et al., AAC, 2009

Organism/Group Oritavancin MIC90 values (g/mL) by reference

Resistant subsetsNicas et al.

(1996)Schwalbe et al.

(1996)Jones et al.

(1996)Biavasco et al.

(1997)Zeckel et al.

(2000)Noviello et al.

(2001)Arhin et al.

(2009)

S. aureus

Methicillin-susceptible 0.5 − 2 4 2 4 0.12

Methicillin-resistant 0.5 1 4 4 2 4 0.12

CoNS

Methicillin-susceptible − − 4 4 2 − 0.25

Methicillin-resistant 0.5 1 8 4 2 − 0.25

S. haemolyticus − 2 2 4 − − 0.12

E. faecalis

Vancomycin-susceptible − 1 2 − 1 1 0.06

Vancomycin-resistant − 2 2 − − − 1

E. faecium

Vancomycin-susceptible − 0.5 0.25 − 0.5 0.25 0.03

Vancomycin-resistant − 1 4 − 2 2 0.25

S. pneumoniae

Penicillin-susceptible − − ≤0.015 ≤0.03 0.008 ≤0.03 0.004

Penicillin-resistant − − 0.06 ≤0.03 0.015 ≤0.03 0.008

β-hemolytic streptococci

Group A − − 0.5 0.25 − − 0.25

Group B − − 0.25 − − − 0.25

Group C 1 − − − − -

Group G 1 − − − − -

A10


A11*From Arhin et. al. Agents Chemo. 2008; 52: 1597-1603

Oritavancin activity as tested against staphylococcal species/groups and resistant subsets submitted to the International Oritavancin Resistance Surveillance follow application of P-80 (first three years)

Oritavancin activity as tested against staphylococcal species/groups and resistant subsets submitted to the International Oritavancin Resistance Surveillance follow application of P-80 (first three years)

Organism / MIC (g/ml) Cumulative % of isolates inhibited at each MIC (g/ml)

Year/Group (no tested) 50% 90% ≤0.008 0.015 0.03 0.06 0.12 0.25

S. aureus

2008

All (6,664) 0.03 0.06 1.8 21.5 77.1 97.5 99.8 99.9

2009All (4,522) 0.015 0.03 7.0 52.5 92.4 99.2 99.9 100.0

2010

All (5,438) 0.03 0.06 4.3 42.2 85.2 96.9 99.5 100.0

OXA-S (3,269) 0.03 0.06 4.5 41.1 84.8 96.9 99.4 100.0

VAN MIC, ≤1 g/ml (3,248) 0.03 0.06 4.6 41.1 84.9 96.9 99.4 100.0

VAN MIC, 2 g/ml (21) 0.03 0.06 0.0 42.9 76.2 100.0

OXA-R (2,169) 0.03 0.06 3.9 43.9 85.8 96.8 99.6 100.0

VAN MIC, ≤1 g/ml (2,136) 0.03 0.06 4.0 44.5 86.5 97.2 99.7 100.0

VAN MIC, 2 g/ml (33) 0.06 0.12 0.0 3.0 39.4 72.7 93.9 100.0

A12

Telavancin AST HistoryTelavancin AST History

• No P‐80 supplement in microdilution broth until 2014

• Testing re‐evaluated post USA‐FDA and EUCAST/EMA approvals

• Re‐evaluated QC guidelines, testing detail and breakpoints are now published (EUCAST/EMA, USA‐FDA) with P‐80 supplemented broth

• Potency of telavancin like those of other lipoglycopeptides (S. aureus MIC 50/90 at 0.06 µg/mL)

A13


Conclusions for Lipoglycopeptide ASTConclusions for Lipoglycopeptide AST

• Requires modified reference MIC tests

– Broth microdilution with 0.002% polysorbate‐80

• Agar dilution and diffusion methods are compromised

• Limited availability of commercial methods, especially automated systems

– Surrogate testing strategies have been suggested

A14






*Six new drug breakpoints evaluated in the last year

B1

B2*From CLSI M07-A10 2015

Endpoint Reading Exceptions for LinezolidEndpoint Reading Exceptions for Linezolid


B3*From CLSI M07-A10 2015

B4*From Mendes et. al. J. Antimicrob. Chemo. 2014; 69: 1582-1588

Summary of non-susceptibility rates documented for linezolid when tested against a total of 52,082 clinical isolates included in the 9 year ZAAPS Program (2004-2012)

Summary of non-susceptibility rates documented for linezolid when tested against a total of 52,082 clinical isolates included in the 9 year ZAAPS Program (2004-2012)

Activity of Tedizolid and Linezolid against Pathogens with Important Resistant Phenotypes in the 2011-2012 STAR Program

Activity of Tedizolid and Linezolid against Pathogens with Important Resistant Phenotypes in the 2011-2012 STAR Program

Organism (N) Antimicrobial MIC50 MIC90

Cum. percentage of isolates inhibited at MIC (µg/mL) of:

≤0.25 0.5 1 2 4

MRSA (1770) Tedizolid 0.25 0.5 65.9 99.7 99.8 99.9 100.0

Linezolid 2 2 0.2 0.5 31.3 97.0 99.7

MSSA (2729) Tedizolid 0.25 0.5 66.0 100.0 ‐ ‐ ‐

Linezolid 2 2 0.2 0.5 25.3 94.5 99.7

VRE (163) Tedizolid 0.25 0.5 62.6 98.8 99.4 100.0 ‐

Linezolid 2 2 0.0 1.2 41.7 98.8 99.4

VSE (705) Tedizolid 0.25 0.5 87.4 100.0 ‐ ‐ ‐

Linezolid 1 2 0.6 6.5 58.4 99.7 100.0

B5*From Sahm et. al. Diagn. Microb. Inf. Dis. 2015; 81: 112-118


Direct comparison of Thermo Fisher tedizolid MIC testing device (Sensititre®) results to that of reference frozen-form panel values (285 strains)

Direct comparison of Thermo Fisher tedizolid MIC testing device (Sensititre®) results to that of reference frozen-form panel values (285 strains)

B6*From Jones et. al. J. Clin. Microbiol. 2015; 53: 657-659

Variation in log2 dilution steps:

Organism (no. tested) ‐2 ‐1 Exact +1 +2 % Essential Agreement

S. aureus (110) 0 6 89 15 0 100.0

CoNS (20) 0 1 16 3 0 100.0

Enterococci (40) 0 0 28 12 0 100.0

S. pneumoniae (30) 0 2 26 2 0 100.0

β‐hemolytic streptococci (70) 0 21 47 2 0 100.0

S. anginosus group (15) 0 5 7 3 0 100.0

All strains (285) 0 35 213 37 0 100.0

Conclusions for Oxazolidinone ASTConclusions for Oxazolidinone AST

• Class having potent Gram‐positive spectrum but not considered as cidal agents

• Tedizolid QC range for S. aureus spans the susceptible breakpoint

• Some breakpoint organizations and regulator‐imposed post‐marketing global surveillance programs apply modified endpoint interpretations (80% inhibition, disregard trailing growth)

• Correlate disk diffusion and commercial methods/systems may be delayed and surrogate strategies could be an option (data pending)

B7






*Six new drug breakpoints evaluated in the last year

C1


Combination Drug Testing StrategiesCombination Drug Testing Strategies

• Active agent tested on a log2 dilution schedule with a fixed concentration of the inhibitor for reference MIC method

• Active agent and a validated amount of inhibitor in disks for diffusion method– Active drug traditional disk loading for geographic region (30‐µg/ml or 10‐µg/ml) adjusted to PK‐PD breakpoint

– Inhibitor concentration generally approximating to dosing ratio at 2 or 3: 1 (30‐20, 30‐10, 10‐6 µg proposed)

• Correlative accuracy between breakpoints for the methods shall be predictably acceptable because of the long history of cephalosporin AST methods

C2

50% fT > MIC for Ceftazidime and 50% f T > CT of 1 mg/L Avibactam Following IVAdministration of 2.5g CAZ-AVI q8h (2 hour infusion) Overlaid on a Histogram of MIC Distributions for Enterobacteriaceae collected during 2012 INFORM

50% fT > MIC for Ceftazidime and 50% f T > CT of 1 mg/L Avibactam Following IVAdministration of 2.5g CAZ-AVI q8h (2 hour infusion) Overlaid on a Histogram of MIC Distributions for Enterobacteriaceae collected during 2012 INFORM

C3*From USA‐FDA AIDAC Presentation, 2014

C4

0

10

20

30

40

50

60

70

80

90

100

0.03 0.06 0.12 0.25 0.5 1 2 4 8 16 32

% inhibited

MIC (µg/ml)

Piperacillin‐tazobactam

Ceftazidime

Cefepime

Meropenem

CAZ‐AVI

92.2%89.7%92.5%

98.2% 99.9% susceptible to CAZ‐AVI*

Figure 1. Cumulative percentage activity curves for CAZ-AVIand four comparison agents tested against 9,261 Enterobacteriaceae from USA SENTRY Program (2013)

Figure 1. Cumulative percentage activity curves for CAZ-AVIand four comparison agents tested against 9,261 Enterobacteriaceae from USA SENTRY Program (2013)

*From INFORM Program


C5

Example of Ceftolozane-Tazobactam Activity against P. aeruginosa (USA, 2011-2012)aExample of Ceftolozane-Tazobactam Activity against P. aeruginosa (USA, 2011-2012)a

Organism subsets (no. tested)

Cum. % inhibited at MIC (mg/L):

≤1 2 4 8 16

All strains (1971) 82.6 90.4 96.1b 98.5 99.0

MDR (310) 29.0 55.2 79.0 90.3 93.5

XDR (175) 17.1 45.7 70.9 85.7 90.3

MEM-NS (388) 53.1 71.6 85.3 92.8 95.1

C6

a. From Farrell et al. Antimicrob. Agents Chemother. 57: 6305-6310 (2013)

b. USA-FDA approved breakpoint, Enterobacteriaceae coverage = 93.3% at ≤ 2 mg/L (7,071 strains)

Conclusions for β-lactamase Inhibitor Combination ASTConclusions for β-lactamase Inhibitor Combination AST

• In vitro methods for ceftazidime‐avibactam and ceftolozane‐tazobactam appear sound for MIC reference and disk diffusion testing

• Recommended breakpoints will be consistent with PK‐PD validated high‐dose regimens for a limited number of indications

• Expanded spectrums appear very broad against Gram‐negative pathogens, many with MDR profiles

C7







*Six new drug breakpoints evaluated in the last yearD1

Correlation between polymyxin B and colistin MIC values when testing 15,377 Gram-negative bacilli collected worldwide in 2013

Correlation between polymyxin B and colistin MIC values when testing 15,377 Gram-negative bacilli collected worldwide in 2013

D2

Scattergram showing polymyxin B MIC results obtained with versus without the addition of P-80 to the MHB (all species: N=247)

Scattergram showing polymyxin B MIC results obtained with versus without the addition of P-80 to the MHB (all species: N=247)

D3*From Sader et. al. Diagn. Microb. Inf. Dis. 2012; 74: 412-414


Re-evaluation of Polymyxin AST:Report of the Joint EUCAST/CLSI ad hoc Polymyxin Breakpoint Working Group

Re-evaluation of Polymyxin AST:Report of the Joint EUCAST/CLSI ad hoc Polymyxin Breakpoint Working Group

• Agents stick to plastics via an electrostatic interaction (concentration dependent)

• PK‐PD data is limited for polymyxin B• Polymyxin components may differ in potency by pathogen

(debated)• Colistin breakpoints will appear in late 2015• Potencies of colistin and polymyxin B are “not quite” comparable• AST methods

– Agar dilution and disk/gradient diffusion are suboptimal– Broth microdilution is reference test, using polystrnene trays not P‐80

• Attend lecture by Professor Turnidge on other revived drugs in Hall B (5:00PM)

D4* Minutes of CLSI Subcommittee, 2015

EMA/CHMP“Ultimate regulatory approval function

for antimicrobial agents including breakpoints”

EUCAST*

“Authority to develop and suggest AST breakpoints”

Has regulated process for interactions with drug sponsors

and agencies (SOP/H/3043)ESCMID

“Support function”

ECDC

“Support function”

*recommends/endorses methods of choice available worldwide (ISO, CLSI etc), and modifies per need of EU region and member NACs; method listed in regulatory documents E1

Stable-Functional Components of EUCAST SystemStable-Functional Components of EUCAST System

Assuming the Development Objectives are Achieved, Do We Still Have a Problem?

Assuming the Development Objectives are Achieved, Do We Still Have a Problem?

• “YES! Getting the breakpoints to the end‐user to favorably influence patient care. Improve implementation of breakpoint updates found in the EUCAST documents via diagnostic systems”

• “Delays of greater than one year would clearly be excessive, if the breakpoint determining process was effective.”

‐R.N. Jones (2015)

E2

Educational Workshop - ESCMID

Documents

Transcript of Educational Workshop - ESCMID