A Broth Microdilution Method for Antibiotic Susceptibility Testing of Gram-Positive Bacteria

Source: Koeth, L. M., et. al., A Reference Broth Microdilution Method for Dalbavancin In Vitro Susceptibility Testing of Bacteria that Grow Aerobically. J. Vis. Exp. (2015).This video demonstrates the broth microdilution method for determining the minimum inhibitory concentration (MIC) of a lipoglycopeptide antibiotic against Gram-positive bacteria. It covers bacterial colony isolation, dilution, inoculation of microplate wells with varying antibiotic concentrations, and verification of culture purity and cell counts. The video also explains how antibiotic binding disrupts cell wall synthesis, leading to lysis, and how to identify the MIC based on visible growth inhibition.