Open AccessIsolated cell behavior drives the evolution of antibiotic resistance
Author(s) -
Artemova Tatiana,
Gerardin Ylaine,
Dudley Carmel,
Vega Nicole M,
Gore Jeff
Publication year - 2015
Publication title -
molecular systems biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 8.523
H-Index - 148
ISSN - 1744-4292
DOI - 10.15252/msb.20145888
Subject(s) - antibiotics , biology , antibiotic resistance , microbiology and biotechnology , minimum inhibitory concentration , bacterial cell structure , bacterial growth , population , bacteria , genetics , demography , sociology
Bacterial antibiotic resistance is typically quantified by the minimum inhibitory concentration ( MIC ), which is defined as the minimal concentration of antibiotic that inhibits bacterial growth starting from a standard cell density. However, when antibiotic resistance is mediated by degradation, the collective inactivation of antibiotic by the bacterial population can cause the measured MIC to depend strongly on the initial cell density. In cases where this inoculum effect is strong, the relationship between MIC and bacterial fitness in the antibiotic is not well defined. Here, we demonstrate that the resistance of a single, isolated cell—which we call the single‐cell MIC (sc MIC )—provides a superior metric for quantifying antibiotic resistance. Unlike the MIC , we find that the sc MIC predicts the direction of selection and also specifies the antibiotic concentration at which selection begins to favor new mutants. Understanding the cooperative nature of bacterial growth in antibiotics is therefore essential in predicting the evolution of antibiotic resistance.