Antimicrobial Susceptibility Testing: 2023 Updates

Antimicrobial susceptibility testing (AST) to guide targeted antibiotic utilization is a critical function of clinical microbiology laboratories, but the mechanisms of antimicrobial resistance can be confusing and the testing environment complex. In this series, experts in the field of AST will present the latest information on both introductory and advanced topics to give you the AST information you need to do your job, whether that be in a clinical or public health laboratory or as a practicing infectious disease physician.

Learning objectives: 

  • The attendee will be able to describe current best practice AST methods and limitations.
  • The attendee will be able to describe the latest information on bacterial and viral resistance mechanisms.
  • The attendee will be able to describe regulatory aspects of AST for clinical laboratories.

Webinar Topics

Oct. 4: Gram-Negative Resistance Mechanisms and Testing: Enterobacterales

This case-based presentation will review common and emerging mechanisms of antimicrobial resistance among the Enterobacterales. We will review phenotypic and genotypic testing methods available for the detection of antimicrobial resistance mechanisms. Furthermore, we will discuss testing considerations for all sizes of clinical microbiology laboratories and understand the pros and cons of testing modalities presented.

Learning Objectives: 

  • Describe common and emerging mechanisms of resistance among the Enterobacterales.
  • Discuss testing methods for the detection of resistance among the Enterobacterales.
  • Understand the pros and cons of different testing modalities available for the detection of resistance mechanisms among the Enterobacterales.


Oct. 4, 2023
2 p.m. ET


Patricia (Trish) J. Simner, Ph.D., D(ABMM)
Associate Professor of Pathology and Infectious Diseases
Director of Bacteriology, Division of Medical Microbiology
The Johns Hopkins University School of Medicine


Oct. 18: Genotypic/Phenotypic AST Methods

This session will provide an overview of the different methods of antimicrobial susceptibility test methods. The typical phenotypic methods provides comprehensive results but is not rapid if conventional methods are used. Genotypic AST methods allow rapid direct detection of a selected resistance mechanism, but may fail to accurately predict a full susceptibility profile.

Learning Objectives: 

At the end of this presentation, the learner will be able to:
  • Compare and contrast phenotypic from genotypic AST methods.
  • Describe new rapid phenotypic AST methods.
  • Explain use cases for when genotypic vs. phenotypic AST methods may be warranted.


Oct. 18, 2023
2 p.m. ET


Nicholas M. Moore, Ph.D., D(ABMM), MLS(ASCP)CM
Associate Professor, Medical Laboratory Science
Assistant Professor, Department of Internal Medicine
RUSH Medical College


Oct. 19: Gram-Positive Bacterial Antimicrobial Resistance Mechanisms & Susceptibility Testing

Infections due to gram-positive bacteria are the cause of significant morbidity and mortality. Therefore, a thorough understanding of gram-positive bacterial antimicrobial susceptibility testing (AST) and mechanisms of antimicrobial resistance is important. The central aim of this webinar is to increase knowledge of gram-positive bacterial antimicrobial susceptibility concepts important for patient-facing providers and clinical and public health microbiologists. This webinar will also review “novel” gram-positive bacterial agents and their mechanism of action.

Learning Objectives: 

  • Discuss gram-positive bacterial antimicrobial susceptibility testing and reporting.
  • Describe gram-positive bacterial antimicrobial resistance mechanisms.
  • Review “novel” antimicrobials active against gram-positive bacteria.


Oct. 19, 2023
2 p.m. ET


Lars Westblade, Ph.D., D(ABMM)
Associate Professor of Pathology and Laboratory Medicine
Weill Cornell Medicine
Director, Clinical Microbiology Service
NewYork-Presbyterian/Lower Manhattan Hospital and Weill Cornell Medical Center

Oct. 25: Verification/Validation of ASTs for New Drugs

Antimicrobial resistance is a crisis that threatens our ability to treat infectious diseases. As new antimicrobial agents become available, it is critically important for both patient care and public health that clinical laboratories implement antimicrobial susceptibility tests (ASTs) for these new drugs. This webinar aims to increase knowledge about why verification/validation is an essential step before an AST for a new drug is implemented for clinical use, and about factors and resources to consider when designing and executing these studies.

Learning Objectives: 

  • Explain why verification/validation of antimicrobial susceptibility tests (ASTs) for new drugs should be performed as part of a clinical laboratory’s quality assurance program.
  • Describe factors that a laboratory director may consider when using a risk-based approach to the design of an AST verification/validation.
  • Identify resources available to aid clinical laboratories with the verification/validation of ASTs for new drugs.


Oct. 25, 2023
2 p.m. ET


Virginia M. Pierce, M.D., FIDSA
Associate Professor of Pathology
University of Michigan Medical School
Associate Director, Clinical Microbiology Laboratory
Michigan Medicine

Nov. 1: Regulatory Considerations for AST

This talk will review the regulatory landscape surrounding antimicrobial susceptibility testing, beginning with an overview of the U.S. government agencies that oversee approval of antimicrobial agents and AST devices. Focus will then turn to a description of the organizations that set AST breakpoints and the "lifecycle" of a breakpoint. Finally, recent breakpoint-related changes to the College of American Pathologists' microbiology checklist will be discussed.

Learning Objectives: 

  • Name the U.S. government agencies that approve antimicrobial agents and AST devices.
  • Name standards development organizations that set AST breakpoints.
  • Describe the "lifecycle" of a susceptibility testing breakpoint.
  • List key recent microbiology checklist changes pertaining to susceptibility testing from the College of American Pathologists.


Nov. 1, 2023
2 p.m. ET


Isabella Martin, M.D., D(ABMM)
Medical Director of Microbiology
Department of Pathology and Laboratory Medicine
Dartmouth Health

Nov. 8: Antiviral Resistance Testing

This talk with cover phenotypic and genotypic antiviral resistance testing, commonly performed in clinical and reference labs.

Learning Objectives: 

  • Describe approaches to phenotypic testing for antiviral testing.
  • Describe Sanger-based methods for genotypic testing for antiviral testing.
  • Describe NGS-based methods for genotypic testing for antiviral testing.


Nov. 8, 2023
2 p.m. ET


Alex Greninger, M.D., Ph.D., M.S., M.Phil.
Assistant Director, Medicine Clinical Virology Laboratory
Director, Retrovirology/Clinical Trials Laboratory
Assistant Professor, Laboratory Medicine and Pathology
University of Washington

Nov. 15: Troubleshooting Unusual Antimicrobial Susceptibility Results

Organisms don’t always follow the rules—especially when resistance mechanisms come into play! Troubleshooting unusual antimicrobial susceptibility patterns and results will be demonstrated through cases of gram-negative bacteria, gram-positive bacteria and Candida auris.

Learning Objectives: 

  • Recognize unusual antimicrobial susceptibility patterns.
  • Formulate a plan to resolve discrepancies between genotypic and phenotypic test results.
  • List alternate tests or approaches to reach a conclusion regarding unusual antimicrobial susceptibility results.


Nov. 15, 2023
2 p.m. ET


Audrey N. Schuetz, M.D., D(ABMM)
Professor of Laboratory Medicine and Pathology
Consultant, Divisions of Clinical Microbiology and Anatomic Pathology
Director, Clinical Microbiology Core Laboratory
Co-Director, Bacteriology Laboratory
Mayo Clinic

Nov. 29: Gram-Negative Resistance Mechanisms & Testing (Non-Enterobacteriaceae)

This webinar will evaluate testing challenges for non-fermenting bacteria, through the lens of CLSI and EUCAST standards. Pseudomonas aeruginosa, Acinetobacter spp. and Stenotrophomonas maltophilia will be the focus.

Learning Objectives: 

  • Describe intrinsic resistance patterns in Pseudomonas aeruginosa, Acinetobacter and Stenotrophomonas maltophilia.
  • Evaluate key testing challenges for common non-fermenting gram-negative bacilli.
  • Discuss strategies for approaching testing of newer drugs for multi-drug resistant isolates.


Nov. 29, 2023
2 p.m. ET


Romney Humphries, Ph.D., D(ABMM), F(AAM), FIDSA
Division Director, Laboratory Medicine
Service Director, Infectious Diseases Laboratories
Vanderbilt University Medical Center


  • There are 8 webinars in this series. 
  • Each webinar will be presented live and the recording of that presentation will be available within 3 business days. 
  • Each webinar's content is independent and does not build on the previous webinars in the series, so learners can purchase only those that meet their needs.


Clinical laboratory technologists, supervisors and directors; as well as public health technologists and staff; infectious disease fellows and physicians and pathology residents.

Level of Instruction

Intermediate to advanced (per webinar).

Continuing Education (CE) Credit

Each presentation is approved for 0.5 P.A.C.E.® credit. ASM is approved as a provider of continuing education programs in the clinical laboratory sciences by the ASCLS P.A.C.E.® Program. All presentations are recognized by the California Department of Health and Florida Department of Health and qualify for California and Florida CE credit toward license renewal. CE credits can only be claimed by the purchaser (individual sales only). 

Please email ASM (see contact information below) if you require closed captioning.


Supported in Part Through Educational Grants From:
Ferring Pharmaceuticals

Source: Ferring Pharmaceuticals

Source: Illumina
Luminex, A DiaSorin Company

Source: Luminex, A DiaSorin Company
Roche Diagnostics

Source: Roche Diagnostics

Registration Details

For Individuals

8-Webinar Bundle
ASM members: $126
ASM supporting members and non-members: $178

Purchase price includes unlimited access to the webinars, through Oct. 3, 2024, and continuing education (CE) credit for the purchaser.

Individual Webinars
ASM members: $17 each
ASM supporting and non-members: $24 each

Purchase price includes unlimited access to the webinars, through Oct. 3, 2024, and continuing education (CE) credit for the purchaser.

Join ASM to receive the best discounts on webinar registrations and more!

For Institutions

An institutional subscription is available for this course for $130 per webinar ($1,036 for the bundle). Purchase of institutional subscriptions will allow access and CE credit for up to 10 users. Please email ASM staff at to purchase an institutional subscription.


Contact Information

Nicole Jackson,