Minimal inhibitory concentration (MIC) test and determination of antimicrobial resistant bacteria

Abstract

The agar dilution technique is used to measure qualitatively the in vitro activity of an antimicrobial agent against the test bacteria. In this method, graded amounts of antibiotics are incorporated in agar plates and inoculated in spots with the organisms under study. If the organism under study is susceptible to the incorporated antibiotic, no bacterial growth is expected in agar plates with higher amounts of the drugs. Bacterial growth is observed as the antibiotic concentration in the agar plate diminishes. Inhibition of growth at the minimum or lowest concentration of antibiotic is regarded as the end point.