Join us in celebrating our 50th Anniversary!
Join us in celebrating our 50th Anniversary!

M23: Development of In Vitro Susceptibility Testing Criteria and Quality Control Parameters, 6th Edition

CLSI requests nominations for volunteers to serve as members and advisors on a working group for a document revision.


CLSI document M23 will provide direction for determining breakpoints and quality control (QC) parameters for antimicrobial agents that have a direct action on microorganisms. The intended audience includes sponsors (eg, antimicrobial agent manufacturers) planning to submit data to establish or revise QC ranges and susceptibility testing breakpoints and interpretive categories for inclusion in CLSI susceptibility testing documents. Anticipated revisions include but are not limited to:

  • Clarifying the use of M23 by the Subcommittees on Antifungal Susceptibility Tests and Veterinary Antimicrobial Susceptibility Testing
  • Harmonizing disk content with the European Committee on Antimicrobial Susceptibility Testing (EUCAST)
  • Clarifying the use of epidemiological cutoff values
  • Including an intermediate breakpoint for disk diffusion when one does not exist for broth dilution
  • Clarifying the requirements for testing media for disk diffusion
  • Providing guidance on acceptable error rates between disk diffusion and broth dilution results for antimicrobial agents designed to treat less-susceptible organisms

This group is looking for volunteers with:

  • Understanding of basic microbiology, pharmacokinetics-pharmacodynamics, and the interpretation of antimicrobial agent clinical studies
  • Understanding of the current process used by CLSI to determine interpretive criteria/breakpoints

Additional information on essential job duties and skills and abilities for CLSI committee participants can be viewed here.

Timeline for this project

June 3, 2018: First face-to-face meeting (NOTE: This will be a 3-hour meeting scheduled during the Subcommittee on Antimicrobial Susceptibility Testing meeting at the June Committees Week in San Diego, California.)
June 2018 to June 2019: Drafting of document (higher-intensity volunteer time period)
September 2019 to November 2019: Voting period for draft document
December 2019 to February 2020: Revision of draft based on comments received during voting
June 2020: Expected publication date

Due date for submission of required documentation

Please submit nominations and required documentation (see Requirements for Nomination Consideration) on or before April 30, 2018 to