Answer :
Final answer:
The minimum inhibitory concentration (MIC) is the lowest antimicrobial medication concentration that prevents visible growth of a bacterial strain in vitro. It is crucial for selecting effective treatments, while the minimal bactericidal concentration (MBC) measures the lowest concentration that kills 99.9% of bacteria.
Explanation:
The minimum inhibitory concentration (MIC) is defined as the lowest concentration of an antimicrobial medication needed to prevent the visible growth of a specific bacterial strain in vitro. This measurement is crucial in determining the effectiveness of an antimicrobial drug against a certain bacteria, assisting clinicians in selecting the appropriate treatment. Traditionally, MIC is determined using dilution tests such as macrobroth or microbroth dilution methods, where an antimicrobial is diluted in successive concentrations, and the presence of microbial growth is assessed visually or by detecting changes in turbidity. The MIC is the point at which no further visible growth occurs, indicating that the bacterial growth has been effectively inhibited by the drug. Different methods like the Etest combine diffusion with dilution techniques to find the MIC on a gradient scale. Conversely, the minimal bactericidal concentration (MBC) is the lowest concentration that kills 99.9% of the bacterial population and is typically ascertained following the MIC assessment.
