Which automated systems are commonly used for MIC testing?

• A. VITEK 2
• B. Phoenix
• C. Both VITEK 2 and Phoenix
• D. None

Answer: (C)

Determining the minimum inhibitory concentration (MIC) is about finding the lowest antibiotic concentration that prevents visible growth of a bacterium. Automated systems like VITEK 2 and Phoenix are widely used for MIC testing because they streamline this process with standardized, rapid assays and automatic reading. VITEK 2 uses predefined microdilution cards that contain multiple antibiotics; the bacterial suspension is added, the card is incubated, and the instrument detects growth changes to generate MIC values and interpretive categories. Phoenix employs broth microdilution panels in a tray and uses an optical reader to assess growth in each well, again providing MICs and susceptibility results. Both platforms are common in clinical labs because they reduce hands-on time, improve consistency, and align with guidelines for antibiotic stewardship. That’s why using both systems is the best choice.