MEASURING DRUG RESPONSES--BEYOND THE MINIMAL INHIBITORY CONCENTRATION

While the minimal inhibitory concentration (MIC) has been used as the standard measure of drug response for bacteria and fungi, it is not the only relevant parameter regarding response to drug. In particular, the ability of cells to survive and divide in the presence of the drug (including processes defined as tolerance, persistence and heteroresistance) can be important for drug responses and the ability of infections to recurr. Here we present a quantitative assay of supra-MIC growth and we describe perserverence, a mechanism of growth in drug with some features seen for antibiotic tolerance in bacteria.