eucast: update on current guidelines plus uk specific...
Post on 14-Jun-2020
2 Views
Preview:
TRANSCRIPT
Insert name of presentation on Master Slide
EUCAST: Update on current guidelines plus UK specific advice v 9.0
Mandy Wootton
What’s new in EUCAST
Links to Expert rules & resistance docs added High dose therapy markers Taxomomic name changes Addition of BPs for new agents Revised BPs S. pneumoniae & H. influenzae – new flowcharts Redefinition of the Intermediate category Area of Technical Uncertainty (ATU) category added
Expert rules and Resistance mechanism docs
High dose therapy markers
Taxonomic name changes
Enterobacter aerogenes to Klebsiella aerogenes
– It has a native ampC ß-lactamase (like Enterobacterspp. but unlike Klebsiella spp.
– Treat as Enterobacter for susceptibility patterns
– Treat as Enterobacter for ESBL detection
Clostridium difficile to Clostridioides difficile
Proprionibacterium acnes to Cutibacterium acnes
Breakpoints for new agents
Meropenem-vaborbactam– MIC BPs only for Enterobacterales and Pseudomonas spp.
– Vaborbactam fixed conc 8mg/L
– Disc criteria in preparation
– MEV: activity against KPC producing Enterobacterales
– Complicated UTI
Breakpoints for new agents
Eravacycline– MIC BPs only for E. coli (only), S. aureus (only), Enterococci and
viridans streptococci
– Disc criteria in preparation
– Intra-abdominable infections
New agents: being worked on in 2019
Aztreonam/avibactam - active against Enterobacteriales with MBLs
Cefiderocol - active against ESBL, MBL, KPC, OXA-23 producers, Ab, Steno, Burk
Cefepime-tazobactam - ESBL producers
Delafloxacin - new FQ for skin infections
Imipenem-Relebactam - active against KPC producers and carb R PAER
Lefamulin - active against SPN, HI, MC for respiratory infections
Iclaprim - active against Gram positives in SSTI
Revised breakpoints
Carbapenems
BPs established in 2008
Changed in – Enterobacterales, – Pseudomonas, – Acinetobacter, – S. pneumoniae, – H. influenzae, – G+ and G- anaerobes.
PKPD
1
8
1/228/16
Enterobacterales
S. pneumoniae
Addition of a new AMP disc breakpoint
S. pneumoniae
Updated flowchart
H. influenzae
Addition of a flowchart
Better detection of BL Res
Reduces no of cephinasetests performed
Redefinition of the Intermediate category
OLD definitions
Clinically Susceptible (S)a micro-organism is defined as susceptible by a level of antimicrobial activity associated with a high likelihood of therapeutic success
Clinically Intermediate (I)a micro-organism is defined as intermediate by a level of antimicrobial activity associated with indeterminate therapeutic effect
Clinically Resistant (R) a micro-organism is defined as resistant by a level of antimicrobial activity associated with a high likelihood of therapeutic failure.
Redefinition of the Intermediate category
Redefinition of the Intermediate category
Dosing and mode of administration are in the EUCAST breakpoint table
Redefinition of the Intermediate category
All clinical breakpoints are related to the achievable level ofexposure* of the microorganism
Redefinition of the Intermediate category
Definition of Intermediate
Redefinition of the Intermediate category
Definition of Intermediate encompasses both…
Redefinition of the Intermediate category
Uncertainty and Exposure
Redefinition of the Intermediate category
Uncertainty and Exposure
Redefinition of the Intermediate category
NEW Definitions
Redefinition of the Intermediate category
NEW Definitions
Redefinition of the Intermediate category
NEW Definitions
Redefinition of the Intermediate category
Definition of OLD Intermediate
Redefinition of the Intermediate categoryProblems & Inconstsencies Some BPs needed revising
The treatment of infections with Pseudomonas spp require most often increased exposure – therefore wild type Pseudomonas should have been categorized ”Susceptible, increased exposure” for all antimicrobials except possibly carbapenems. The committee decided that more time is needed to explain that carbapenems should not because of this be preferred over other available antimicrobials.
The treatment of Enterobacterales with aminopenicillins and cefuroxime require increased exposure and should have been categorized ”Susceptible, increased exposure”. A general consultation on these issues is needed before a final decision so for 2019 wild type organisms will be reported ”Susceptible” with a note to use ”increased exposure”.
Redefinition of the Intermediate category
When S, increased exposure is the result AND HE symbol present, laboratories should consider adding information about the need for high exposure.
This is particularly important with
Pseudomonas and piperacillin-tazobactam, ceftazidime, cefepime, imipenem, aztreonam, fluroquinolones, aminoglycosides.
Enterobacterales and aminopenicillins without or with inhibitor and cefuroxime.
Redefinition of the Intermediate category
ReportingWe can report ”Susceptible (S)” and ”Resistant (R)” but can no longer be reported ”intermediate” to an agent and should instead be reported ”Susceptible, increased exposure (I)”.
EUCAST suggests one of the following wordings are included in reports:
An organism is categorised as Susceptible, increased exposure (abbreviated “I”) when there is a high likelihood of therapeutic success because exposure to the agent can be increased at the site of infection by adjusting the dosing regimen, mode of administration or because the concentration is naturally high at the site of infection (see http://www.eucast.org/clinical_breakpoints/).
This isolate is Susceptible to the agent provided higher exposure of the microorganism can be achieved (dose, frequency, mode of administration).
Area of Technical Uncertainty (ATU)
OLD and NEW definitions
There are situations where the test is known to be poorly reproducible, even when performed appropriately (i.e. with good consumables, QC etc).
Removed from NEW definition of I
Examples of where a warning against uncertain and poorly reproducible results is warranted:
Amoxicillin-clavulanic acid vs. Enterobacterales.– WT distribution of most Enterobacterales end at 8 mg/L. – PK/PD indicates a breakpoint of maximum 8 mg/L and then only if high
exposure is achieved (except for in UTI-32mg/L). – Unfortunately, when determining MICs or disk diffusion test results,
there is poor reproducibility in the critical area 16 mg/L.
Piperacillin-tazobactam vs. Enterobacterales.– WT distribution of most Enterobacterales end at 8 mg/L. – PK/PD indicates a breakpoint of 8/16 mg/L with the highest possible
exposure for organisms in the I-category. – Unfortunately, when determining MICs or disk diffusion test results,
there is poor reproducibility in the critical area 16mg/L.
Area of Technical Uncertainty (ATU)
Area of Technical Uncertainty (ATU)
Area of Technical Uncertainty (ATU)
Area of Technical Uncertainty (ATU)
Area of Technical Uncertainty (ATU)
Area of Technical Uncertainty (ATU)
Area of Technical Uncertainty (ATU)
Enterobacterales 4 agents
Pseudomonas spp 2 agents
Staphylococcus spp 4 agents
H. influenzae 8 agents
Other species 0 agents
Area of Technical Uncertainty (ATU)
For laboratory action:
The warning affects the laboratory, not the clinician, and the laboratory needs a strategy to (1) ascertain the correctness or (2) to report the uncertainty of the result.
Area of Technical Uncertainty (ATU)
For laboratory action: Repeat the test – this is only if there is reason to suspect a technical error. Perform an alternative test (perform an MIC, a PCR, a test to determine
the resistance mechanism) – this is relevant when the alternative test is considered conclusive (PCR to detect a vanA or vanB gene in enterococci, a beta-lactamase test in H. influenzae).
Report results in the ATU as “uncertain” – this can be achieved by leaving a blank with a comment or by developing the LIS to deliver an asterix(instead of an S, I or R) which points to a comment explaining the uncertainty.
Report results in the ATU as “R”. If there are several good alternatives in the AST report this may be the easiest and safest option.
Take the opportunity to discuss the results with the clinician
Area of Technical Uncertainty (ATU)
ATU - the appropriate action may vary with circumstances:
IF few antibiotics available to the clinician, THEN try to achieve
trustworthy categorisation.
IF in a blood culture, THEN try to achieve trustworthy categorisation.
IF can be solved with an alternative method without delay, THEN try to achieve trustworthy categorisation.
IF many alternative antibiotics available, THEN report R (with or without a comment).
IF the result must be reported, THEN include a comment to discuss uncertainty.
Any Questions?
N. gonorrhoeae
EUCAST disc method not available
Reference method: Agar dilution Study with Colindale, European GC & EDL
Comparing agars for agar dilution
Comparing agars for gradient strips
Develop a disc method if possible in time
Interim measures: MIC using gradient strips, use manufacturers media choice
Continue with BSAC disc method
Update of BSAC ”UK Specific Advice” in 2018
EtestBioMerieux
MIC Test Strip
Liofilchem
GC agar base + 1%
IsoVitalex
GC agar base + 1%
IsoVitalex
MH + 1% IsoVitalex +
1% haemoglobin
MH Chocolate
agar
Combination discs for ESBL detection
Combination discs usually contain 30ug of cephalosporin Some ceph 10ug discs on market
EUCAST: 10ug CAZ, 10ug CPD, 5ug CTX Do 30ug and 10ug discs detect ESBLs?
Conclusion: 30ug and 10ug Ceph discs detect ESBLs in combination discs.
top related