The MIC is among the standard infectious disease concepts which has thus far been left out of CICM SAQs. One can expect that at some stage the trainees will be called upon to define it, or to use MIC data to decide which antibiotic to use within a given scenario.
MIC is the lowest concentration of an antimicrobial that will inhibit the visible growth of a microorganism after overnight incubation.
The results are usually reported as µg/mL.
How one arrives at this figure is described in detail in this 2001 article.
A lower MIC indicates that the antibiotic is more effective.
Andrews, Jennifer M. "Determination of minimum inhibitory concentrations."Journal of antimicrobial Chemotherapy 48.suppl 1 (2001): 5-16.
Lambert, R. J. W., and J. Pearson. "Susceptibility testing: accurate and reproducible minimum inhibitory concentration (MIC) and non‐inhibitory concentration (NIC) values." Journal of applied microbiology 88.5 (2000): 784-790.