Figure 4.

Effect of specific gene inactivation on S. suis persister formation. Exponential (A) or stationary (B) grown S. suis strains were treated with 100-fold MIC of gentamicin over time. Persister cell levels were determined for the wild type strain 10, and its knock-out mutant strains 10∆ccpA and 10∆AD, which lack the genes coding for the global transcriptional regulator CcpA and the catabolic arginine deiminase system, respectively. The values are means of three biological replicates and error bars indicate the standard deviation. Significant differences to wildtype persister levels were calculated by a one-tailed t-test (*, P < 0.05; **, P < 0.01).