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Insert name of presentation on Master Slide Automated systems: an overview Robin A Howe Cardiff.

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Presentation on theme: "Insert name of presentation on Master Slide Automated systems: an overview Robin A Howe Cardiff."— Presentation transcript:

1 Insert name of presentation on Master Slide Automated systems: an overview Robin A Howe Cardiff

2 AST standards MIC taken as standard measure of susceptibility –Agar dilution –Broth dilution –Microbroth dilution

3 ISO standard –Broth microdiluion –Mueller-Hinton Broth –Inoculum 5x10 5 cfu/mL

4 AST standards MIC taken as standard measure of susceptibility –Agar dilution –Broth dilution –Microbroth dilution S/I/R Breakpoints defined by BSAC/EUCAST/CLSI

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6 AST standards MIC taken as standard measure of susceptibility –Agar dilution –Broth dilution –Microbroth dilution S/I/R Breakpoints defined by BSAC/EUCAST/CLSI MIC/BP supplemented by expert rules for clinical use

7 The rationale for automated systems More reliable AST results –?closer to standard –Reduced scope for user error –Reproducible Improved ID linked to AST Embedded expert rules Automated systems: an overview

8 Identification required for interpretation of BP & expert rules

9 Welsh variability in ID of Enterobacter/Klebsiella/Serratia

10 The rationale for automated systems More reliable AST results Improved ID linked to AST Embedded expert rules Improved speed of results Increased number of agents tested Automated systems: an overview

11 Welsh Gram negative panel Welsh Gram positive panel

12 The rationale for automated systems More reliable AST results Improved ID linked to AST Embedded expert rules Improved speed of results Increased number of agents tested Laboratory workflow Staff skill mix Epidemiological software Automated systems: an overview

13 Available systems MicroScan WalkAway Biomerieux Vitek 2 BD Phoenix

14 MicroScan 96 well plates AST based on conventional microbroth dilution MIC ID currently biochemical

15 Microscan Conventional panels Enterobacteriaceae, gram-negative non- fermenters, staphylococci, enterococci Combo, MIC-only, ID-only Rapid panels – hour ID (pre-formed enzymes) –AST for Gram negative organisms (MIC > 4 hrs) Synergies plus panels – hour ID (pre-formed enzymes) –Broth microdilution Read-when-ready MIC –Resistance detection flagged in as few as 4.5 hours –All results finalized in 16/18 hours Additional –Yeast ID, Anaerobe ID, HNID –MICroSTREP plus ® - dry format –ESβL plus ® -ESβL Confirmatory Panel Panels read by –WalkAway ® systems –autoSCAN-4 –Manual

16 Microscan Expert rules within LabPro Alert system –Pre-loaded –customisable

17 Microscan Expert rules within LabPro Alert system –Pre-loaded –customisable

18 Vitek 2 AST based on broth susceptibility with specific cards ID currently biochemical Growth/reactions continuously monitored

19 Vitek 2 ID Cards available for –Gram positives –Enterobacteriaceae –Non-Enterobacteriaceae –Neisseria/Haemophilus etc –Anaerobes –Yeasts AST Cards available for –Gram positive cocci –Gram negative bacilli –Yeasts Up to 22 antibiotics tested on each card

20 TIME (hours) Raw Data % Change Slope Area SLPAR Interpretation of Raw Data Growth Parameters MIC VITEK 2 – MIC Interpretation

21 Vitek 2 Expert rules within the Advanced Expert System (AES) –Extensive Knowledge Base >20,000 MIC distributions >2,500 Phenotypes >200 Resistance Mechanisms

22 Vitek 2 CARD TypeTime to Result GN ID 2 to 10 hours GP ID 2 to 8 hours NH ID6 hours ANC ID6 hours YST ID18 hours GN AST2 to 18 Hours GP AST2 to 18 Hours AST-YS01 6 hours

23 Phoenix AST based on broth susceptibility with specific cards ID currently biochemical Growth/reactions continuously monitored

24 Phoenix AST only or Combo panels available for –GN (Enterobacteriaceae/ Nonfermenters) –GP (Staphylococci/ Enterococci/ Streptococci) –Streptococci ID/AST

25 Phoenix Readings for each well taken and calculated every 20 minutes –ID uses red, green, blue and UV light sources –AST measures turbidity and color change –Each well divided into pixels –Readings taken for each pixel –Entire process takes 7 minutes –Pixel data analyzed for each well –Readings for each well compared to previous reading and baseline Well is complete when specific amount of change is not seen Substrate/antimicrobic algorithm dependent –Instrument will post results when enough data collected

26 Phoenix Expert rules within BDXpert based on CLSI/SFM/DIN/EUCAST rules bases

27 Comparison of systems

28 Performance ID –Correct to genus >95% –Correct to Species>90% –Difficulties with difficult organisms Non-fermenters Shigella etc AST –Concordant with other methods >95% –Specific issues with specific drug-bug combinations & certain instruments VISA/VRSA Beta-lactams & Pseudomonas

29 Performance ID/AST performance relies on correct ID, correct AST plus appropriate expert interpretation –Incorrect ID can lead to incorrect AST Up to 5% errors mean that results should be examined critically

30 Conclusions Automated systems can provide –Reliable AST integrated with ID & expert rules –Improved speed of results Caution about staff skill mix and interpretation of results Microscan/ Vitek 2 /Phoenix have similar performance overall –Results should be examined critically

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