Minimal inhibitory concentration (MIC)

Definition

Minimal Inhibitory Concentration (MIC) is the lowest concentration of an antimicrobial agent that inhibits visible growth of a microorganism after overnight incubation. It helps determine the effectiveness of antibiotics against specific pathogens.

5 Must Know Facts For Your Next Test

1. MIC values are critical for determining the susceptibility of bacteria to various antimicrobials.
2. The MIC is usually measured in micrograms per milliliter (µg/mL).
3. Broth dilution and agar dilution methods are commonly used to determine MIC.
4. MIC can help guide the selection of appropriate antibiotic therapy for infections.
5. A lower MIC value indicates a more effective antimicrobial agent against the tested organism.

Review Questions

• What does MIC stand for and what does it measure?
• Why is knowing the MIC important when treating bacterial infections?
• Which methods are commonly used to determine an organism's MIC?

Related terms

Broth Dilution Method: A technique used to determine the MIC by diluting antibiotics in broth with a standard inoculum of bacteria.

Agar Dilution Method: A technique where different concentrations of an antibiotic are incorporated into agar plates to determine the MIC.

Antibiotic Susceptibility Testing: Testing to determine whether specific bacteria are susceptible or resistant to particular antibiotics.