Correlation between polymyxin B and tobramycin persister cells in the sample population.

<p>Correlation between polymyxin B and tobramycin persister cells in the sample population.</p

Frequency distribution of the persister fractions.

<p>Persister producer strains were grouped in 6 classes (defined by the square root of sample size) according to their persister fraction in the population after polymyxin B (a) or tobramycin (b) exposure. Most isolates presented persister fractions that corresponded to less than 1.2% and 0.5% of the total population for polymyxin B and tobramycin, respectively.</p