AST of bacteria

Development and validation of EUCAST Disk Diffusion breakpoints

The EUCAST Disk Diffusion test was developed by EUCAST during 2009 - 2013 under the auspices of ESCMID and with the help of many laboratories. The help of these laboratories is gratefully acknowledged.


The files below list material and graphs used for determining zone diameter breakpoints to match MIC breakpoints (Example 1). Also all MIC and zone diameter data are entered in the EUCAST MIC- and Zone diameter distribution program.

All files were updated 2016-01-28 (breakpoints checked against Breakpoint table 6.0 and new graphs added) except Enterobacteriaceae and Haemophilus. Older versions can be obtained from the web master.

  1. Enterobacteriaceae (2016-09-29)

  2. Salmonella spp
  3. Pseudomonas aeruginosa
  4. Pseudomonas non-aeruginosa
  5. Staphylococcus aureus
  6. Staphylococcus, coagulase-negative
  7. Staphylococcus saprophyticus
  8. Staphylococcus pseudintermedius
  9. Enterococcus spp.
  10. Streptococcus pyogenes (Group A)
  11. Streptococcus agalactiae
  12. Streptococcus pneumoniae
  13. Streptococcus pneumoniae - screen for beta-lactam resistance
  14. Viridans Group Streptococci
  15. Haemophilus influenzae (file from 2015, new file under preparation)
  16. Haemophilus influenzae - screen for betalactam resistance (file from 2015, new file under preparation)
  17. Moraxella catarrhalis
  18. Listeria monocytogenes
  19. Pasteurella multocida
  20. Campylobacter jejuni and C. coli
  21. Corynebacterium spp


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