How CLSI Makes AST Possible: A Discussion With CLSI CEO Dr. Barbara Jones

Q: Why is standardized AST foundational to patient care?

A: This is such an important question, not just in antimicrobial susceptibility testing, but at every level of patient care. Standardization of methods ensures that test results can be compared over time, between testing sites, and among testing populations. It is particularly important for the treatment of infectious disease in patients, where their conditions can evolve rapidly and inadequate treatment can pose a risk to entire populations.

Standardized methods are so critical for ensuring testing personnel are well-trained on procedures, and that new personnel are performing testing in the same manner as existing staff. In the end, standardization of test methods may very well be the most important factor in understanding how antimicrobial resistance is affecting patients and communities and how to treat them.

Q: How does CLSI Support labs in staying current as resistance evolves?

A: CLSI breakpoints (minimal inhibitory concentration or zone diameter values used to categorize an organism as susceptible, susceptible-dose dependent, intermediate, or resistant to a specific therapeutic) are the bridge between the laboratory and the clinician in the fight against AMR and the best possible treatment for patients.  Experts in infectious disease, laboratory medicine, veterinary medicine, and pharmaceuticals work through CLSI to update these breakpoints as resistance changes. 

Twice yearly, CLSI brings together these experts from all over the world to present their findings on new breakpoint values, improved methods, and proposed changes to treatment parameters.  All of this massive amount of work is then incorporated into CLSI M100 and other standards and guidelines annually.  CLSI M100 is a critical resource for microbiology laboratories in their recommendations for effective antimicrobial treatment of patients.   

Q: What stood out to you from the WHO's AMR surveillance report?

A: I found it alarming that in 2023, one out of six "laboratory-confirmed bacterial infections causing common illnesses" was resistant to antibiotics. This is shocking, if we understand that our ability to treat infection is becoming more limited every day.  More alarming, on a global scale, was the data that showed that more than 40% of E. coli cases and over 55% of K. pneumoniae cases worldwide are now resistant to third-generation cephalosporins.  This is particularly horrifying when you understand the struggle that resource limited countries have in obtaining and affording second and third-line therapeutics. 

Q: How does standardized AST contribute to meaningful AMR surveillance?

A: In addition to the importance of using standardized methods to ensure that data from populations can be compared and aggregated, CLSI provides accessible methods and tools for determining resistance over a wide array of antimicrobial drug/bug combinations. The consistent and widespread use of CLSI methods and breakpoint values for determining resistance allows epidemiologists and public health authorities to adequately assess information on emerging or evolving resistance. 

Q: How does CLSI plan to continue supporting laboratories in this space?

A: CLSI will always be the forum where the world’s experts in AMR can come together to assist one another in the fight.  We invest heavily in providing the financial and administrative support for this work and are committed to continuing to use our unique consensus process to ensure that stakeholder voices are heard when breakpoint values, methods changes, or practice guidelines are incorporated into the CLSI resources.  In addition, we provide CLSI M100 free of charge through our CLSI MicroFree portal so this critical information can be accessed by anyone who needs it. Since its inception in 2015, the MicroFree portal has been accessed over 20 million times from nearly every country in the world. 

It is very important to understand that the CLSI expert volunteers give their time and resources freely to the people of the world through their work with CLSI.  In many cases, their institutions and laboratories fund research, and in all cases, fund the volunteer time that they dedicate to this effort.  CLSI has the great honor of coordinating this work, but the sacrifice and incredible dedication to the well-being of all people world-wide rests with our volunteers.  

Q: What message would you share with laboratory professionals during AMR Week?

A: We are at war and you are a soldier. Seems a little extreme, right?  I think it is more like a call to action and an acknowledgment of how important your role is. Antimicrobial resistance is one of those issues that doesn’t just stay in your laboratory, or your town, or your country.  What you – specifically you – do can affect a person halfway around the world. Every time you use a trusted method to determine resistance, every time you have the courage to discuss the appropriate treatment options with clinicians, every single time you open CLSI M100...you are fighting this fight.  Keep up the incredible work, stay diligent and committed to your cause, and know that you are a hero. 

Stay Vigilant. Stop AMR.

As AMR continues to evolve, so does the work of the laboratories fighting it. With standardized AST at the center, CLSI is dedicated to equipping laboratories with the tools they need to respond with confidence.

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