Novel Rapid Phenotypic Susceptibility Testing Techniques That Enhance Antimicrobial Stewardship and Clinical Decision-Making

BACKGROUND: Antimicrobial resistance (AMR) is a critical global health challenge, underscoring the need for diagnostic innovations that enable timely, and targeted therapy. Rapid phenotypic antimicrobial susceptibility testing (AST) offers a transformative approach by delivering actionable susceptibility results significantly earlier than conventional methods. This accelerated turnaround is vital for optimizing antibiotic therapy and improving outcomes in severe infections, such as sepsis, where delays in effective treatment increase morbidity and mortality. Despite these advantages, implementation faces challenges, including variability in test performance, lack of standardized protocols, and cost-benefit considerations. CONTENT: This review provides an overview of emerging rapid phenotypic AST technologies, focusing on their clinical relevance and operational implications. We outline the fundamentals of the phenotypic approach, highlight growth-based methods, and summarize evidence, demonstrating the impact of rapid phenotypic AST on reducing time to effective therapy and supporting antimicrobial stewardship. SUMMARY: Rapid phenotypic AST represents a pivotal advancement in combating AMR, offering the potential to bridge diagnostic gaps and enhance patient outcomes through timely, evidence-based antimicrobial therapy.