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MALDI-TOF-MS: A Paradigm Shifter?

MALDI-TOF-MS: A Paradigm Shifter?. Dan Gregson U Calgary/AHS/CLS. MALDI-TOF-MS: A Paradigm Shifter!. Dan Gregson U Calgary/AHS/CLS. Conflict of Interest Disclosures. Honoraria from: None Consultant for: Calgary Laboratory Services Alberta Health Services Research support from:

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MALDI-TOF-MS: A Paradigm Shifter?

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  1. MALDI-TOF-MS: A Paradigm Shifter? Dan Gregson U Calgary/AHS/CLS

  2. MALDI-TOF-MS: A Paradigm Shifter! Dan Gregson U Calgary/AHS/CLS

  3. Conflict of Interest Disclosures • Honoraria from: • None • Consultant for: • Calgary Laboratory Services • Alberta Health Services • Research support from: • BD Diagnostics Canada • Merck Canada • Calgary Laboratory Services

  4. Summary: MALDI for Microbial Speciation • Better. • Faster • Easier • Less expensive

  5. Objectives: • To review the technical advance that allows us to do MALDI-TOF. • To examine how MALDI-TOF performs in the clinical lab. • To examine the potential impact of this technology on clinical laboratories. • To review the impact of this technology on patient management • To examine the differences between competing vendors.

  6. J Gen Microbiol. 1975 Apr;87(2):333-42.

  7. t =

  8. R = Vi2sin(2Θ)/g Ek = .5mv2 V2 = 2Ek/m R = (1/m) x 2Ek sin2Θ/g m = (2Ek /R)(sin2Θ/g)

  9. Ek = .5m(d2/t2) m = 2 Ek (t2/d2) m = (2 Ek/d2)t2 m = Kt2

  10. Surface Assisted Ionization • Surface • Chemical matrices • Metals • Nanoparticles • Ionization source • Laser (variable wavelengths) • Electrospray • Ion gun

  11. Ep = qU Ek = .5m (d2/t2) qU = .5m (d2/t2) 2U(t2/d2) = m/q = m/z

  12. + + + + + + + + + + + + + + + + + + + + + + + + + + + 4 2 1 - + R 3 m/z 5 U Kt2 = m/z

  13. Ampicillin Adducts with MALDI-TOF ANa+ AH+ A2Na+ adapted from Sparbieret al. JCM 2012

  14. Data Processing • Data Cleaning • De-noising • Baseline smoothing • Peak Selection • Data Analysis • Comparison of analyzed organism to library • Algorithms based on • Presence of peaks (+/- weighting) • Relative intensity of peaks (+/- weighting • Create a similarity score.

  15. Norris et al. Int J Mass Spectrom. 2007 February 1; 260(2-3): 212–221

  16. Jacquier et al. Eur J Clin Microbiol Infect Dis

  17. Determination of serotypes of Shiga toxin-producing Escherichia coli isolates by intact cell matrix-assisted laser desorption … Karger et al. Appl Environ Microbiol. 2011 Feb;77(3):896-905.

  18. Diekman/MalorneyAppl. Environ. Microbiol. June 2011 vol. 77 no. 12 4136-414

  19. Bittar et al. International Journal of Antimicrobial Agents 34 (2009) 467–470

  20. Sparbier K. et al MSACL 2012

  21. Burkhardt et al. JOURNAL OF CLINICAL MICROBIOLOGY, Sept. 2011, p. 3321–3324

  22. Fd= .5 v2 p CdA

  23. Effects of MALDI on Microbiology/ID/IPC-PH • Laboratory • Reduced reagent costs • Reduced labour • Faster TAT for ID of most Bacteria/Fungi • ID service • Shorter TAT for organism ID (but not susceptibility) • More species reported. • IPC-PH • Near real time typing for some organisms

  24. Summary: MALDI for Microbial Speciation • Better. • Faster • Easier • Less expensive

  25. Mazeltof

  26. Martiny et al. J. Clin. Microbiol 2012

  27. Martiny et al. J. Clin. Microbiol 2012

  28. Martiny et al. J. Clin. Microbiol 2012

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