Antimicrobial susceptibility testing (AST) determines the effectiveness of different antimicrobial agents against specific bacterial or fungal pathogens. Interpreting these tests involves analyzing the minimum inhibitory concentration (MIC), the lowest concentration of an antimicrobial that inhibits visible growth of a microorganism. Results are typically reported as susceptible (S), intermediate (I), or resistant (R), indicating the likelihood of therapeutic success with a standard dosage regimen. For example, an “S” result suggests the infection is likely treatable with the tested antibiotic at usual dosages, while an “R” implies treatment failure is likely. A visual representation, often a table or chart, correlates the measured MIC with these standardized interpretations, aiding clinicians in selecting the most appropriate therapy.
Accurate interpretation is crucial for optimizing patient care, preventing treatment failures, and minimizing the emergence of antimicrobial resistance. Historically, physicians relied on empirical therapy, choosing antimicrobials based on experience and local resistance patterns. AST provides a targeted approach, allowing for personalized treatment strategies. This targeted approach contributes to improved patient outcomes, shorter hospital stays, reduced healthcare costs, and the preservation of effective antimicrobial agents for future use.
