Antibiotic action of tetracycline used in different concentrations.

<p>These graphs show results of numerical simulations of Eq (<a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1005321#pcbi.1005321.e019" target="_blank">10</a>) parameterized with previously fitted values [<a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1005321#pcbi.1005321.ref023" target="_blank">23</a>]. The x-axis shows the time in hours after antibiotic administration. The different colors indicate the initial antibiotic concentration in fold MIC (see legend). <b>(A)</b> Simplified pharmacokinetics (first-order clearance) of a tetracycline bolus injection with a half-life of 6h. The y-axis indicates the antibiotic concentration in fold MIC. The grey shaded area indicates an antibiotic concentration below MIC. The vertical dotted lines indicate when the antibiotic concentration for different dose levels falls below MIC. <b>(B)</b> Effect of supra-MIC doses on bacterial growth rate (y-axis). Again, the vertical dotted lines indicate when the antibiotic concentration for different dose levels falls below MIC. <b>(C)</b> Effect of sub-MIC concentrations of tetracycline on bacterial population size (y-axis).