EndA-mediated competence-independent DNA degradation is conserved in multiple pneumococcal strains and is growth medium-dependent.

<p>(A) Pneumococcal strains D39, R6, 0100993, Tigr4 and their isogenic derivatives were cultured in THB to 10⁸/ml concentration, washed and resuspended in fresh THB or CTM. The <i>rpsL</i> PCR products (30 µg/ml) were exposed to the pneumococcal strains for the indicated time intervals. The integrity of DNA was visualized by agarose gel electrophoresis. The experiments were repeated independently three times. The results from one typical experiment are shown. (B) Growth kinetics of D39 in THB versus CTM. The experiments were performed independently in triplicates and repeated three times. The means ± SD of one representative experiment are shown.