Contemporary Considerations for Establishing Reference Methods for Antibacterial Susceptibility Testing.

Area of Science:

• Microbiology
• Pharmacology
• Clinical Science

Background:

• Antibacterial susceptibility testing (AST) is crucial for guiding treatment decisions and monitoring antimicrobial resistance.
• Broth microdilution (BMD) has been the gold standard for in vitro AST for 50 years, serving as a benchmark for new drugs and diagnostics.

Purpose of the Study:

• To review current reference methods for in vitro assessment of antibacterial activity.
• To highlight considerations for developing novel reference methods for antibacterial agents.

Main Methods:

• The study describes the established broth microdilution (BMD) method.
• It discusses the limitations of BMD, including poor in vivo mimicry, long turnaround times, and variability.
• Considerations for new reference methods are outlined.

Main Results:

• BMD, while a long-standing reference, presents significant limitations in accurately reflecting in vivo conditions and requires substantial time.
• Novel antibacterial agents, particularly those targeting bacterial virulence, may not be adequately assessed by BMD.
• There is a clear need for new, standardized, and internationally accepted reference methods.

Conclusions:

• Existing reference methods for antibacterial activity assessment, primarily BMD, are insufficient for current and future antibacterial agents.
• Development of new reference methods must prioritize standardization, clinical correlation, and international regulatory acceptance.
• Future research should focus on creating robust and adaptable methods for evaluating a broader range of antibacterial strategies.