Mutant Prevention Concentration, Frequency of Spontaneous Mutant Selection, and Mutant Selection Window—a New Approach to the <i>In Vitro</i> Determination of the Antimicrobial Potency of Compounds

Abstract

The analysis of antimicrobial activity is usually MIC- and minimal bactericidal concentration (MBC)-focused, though also crucial are resistance-related parameters, e.g., the frequency of spontaneous mutant selection (FSMS), the mutant prevention concentration (MPC), and the mutant selection window (MSW). In vitro -determined MPCs, however, are sometimes variable, poorly repeatable, and not always reproducible in vivo . We propose a new approach to the in vitro determination of MSWs, along with novel parameters: MPC-D, MSW-D (for dominant mutants, i.e., selected with a high frequency, without a fitness loss), and MPC-F, MSW-F (for inferior mutants, i.e., with an impaired fitness).

Topics & Concepts