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CLSI AST News Updates

The CLSI Outreach Working Group (ORWG), under CLSI's Subcommittee on Antimicrobial Susceptibility Testing (AST), works to efficiently convey information regarding contemporary AST practices, recommendations, and resources to the clinical microbiology community. This biannual CLSI AST News Update highlights current issues related to antimicrobial susceptibility testing (AST) and reporting.

Volume 8, Issue 1, June 2023

Edited By: Janet A. Hindler, MCLS, MT(ASCP), F(AAM) & Audrey N. Schuetz, MD, MPH, D(ABMM)

View all of the articles below in one PDF by clicking below.

M100 Update

New! CLSI M100-Ed33: Updated Aminoglycoside Breakpoints for Enterobacterales and Pseudomonas aeruginosa

Case Study

Aminoglycoside Case Study

AST Article

The Latest on Testing Cefiderocol

AST Article

New CLSI Intrinsic Resistance Guidance for Fungi

CLSI and the AST Subcommittee

CLSI has subcommittees that are responsible for areas related to AMR. They write draft documents, evaluate and respond to comments on content throughout the document development process, conduct scheduled document reviews, and may be responsible for continual revision of certain documents.

CLSI's AST Subcommittee meets twice per year in a hybrid format (in-person with a virtual component) in January and June. More information can be found in the links below.

How to Get Involved

Working groups are managed by chairholders. If you would like to volunteer to become a member of a working group, please fill out our form below. You can also complete your Volunteer Profile to be placed in the "potential volunteers pool" for future positions.

I’m interested! What are my next steps?

Apply for a Working Group

Free Resources From CLSI

CLSI Free M100 and M27M44S

Performance Standards for Antimicrobial & Antifungal Susceptibility Testing

Access read-only web versions of M100 and M27M44S for free and quickly reference the most trusted AST and antifungal breakpoints. Available online as a convenient companion to our M100 document and M27M44S document.

CLSI Using M100-Ed32

Using M100: Performance Standards for Antimicrobial Susceptibility Testing

Improve your lab's antimicrobial susceptibility testing (AST) by using this self-paced, online learning program. This interactive program will teach you how to navigate the many tables found in CLSI's document M100.


Analysis and Presentation of Cumulative Antimicrobial Susceptibility Test Data, 5th Edition

This guideline describes methods for recording and analyzing antimicrobial susceptibility test data, consisting of cumulative and ongoing summaries of susceptibility patterns of clinically significant microorganisms.

On-Demand Webinars | Recently archived CLSI webinars can be accessed on demand and after six months are free unless noted otherwise.

CLSI On-Demand M39 Webinar

M39: Analysis and Presentation of Cumulative Antimicrobial Susceptibility Test Data Webinar

Learn about CLSI's updated M39 document, Analysis and Presentation of Cumulative Antimicrobial Susceptibility Test Data.

CLSI On-Demand CLSI and CAP Webinar 2022

Breakpoints Matter: Understanding CLSI Efforts and New CAP Requirements to Ensure Appropriate Antimicrobial Treatment for all Patients Webinar

CLSI On-Demand CLSI and CAP 2021 Webinar

Ensuring Quality Beyond the Test: Reporting Antimicrobial Susceptibility Results Webinar

Thursday, January 21, 2021 | 1:00–2:00 PM Eastern (US) Time

CLSI Free On Demand: Rationale Webinar

FDA’s Role in ASTs and Understanding CLSI Breakpoint Decisions Webinar

December 17, 2020 | 1:00-2:00 PM Eastern (US) Time

AST Subcommittee Partnerships

Representatives with expertise in antimicrobials from the following organizations attend and participate in CLSI AST Subcommittee meetings and aid in dissemination of information regarding CLSI decisions and AST issues.

  • American College of Clinical Pharmacy
  • Infectious Diseases Practice and Research Network (ACCP INFD PRN)
  • American Society for Microbiology (ASM)
  • Association of Public Health Laboratories (APHL)
  • ASTM International
  • College of American Pathologists (CAP)
  • European Committee on Antimicrobial Susceptibility Testing (EUCAST)
  • Infectious Diseases Society of America (IDSA)
  • Pediatric Infectious Diseases Society (PIDS)
  • Society for Healthcare Epidemiology of America (SHEA)
  • Society of Infectious Diseases Pharmacists (SIDP)
  • Susceptibility Testing Manufacturers Association (STMA)