Analyses of the ability of CSP1 analogs to induce <i>comX</i> expression and genetic transformation.

<p>Pneumococcal cells were incubated with CSP1 or with each analog at a final concentration of 100 ng/ml. The ability of each peptide to induce the competence regulon was measured by induction of the <i>comX</i> expression using the ß-galactosidase assays in D39pcomX::<i>lacZ</i> cells (A) or by genetic transformation using the <i>rpsL</i> gene in D39 cells (B). Transformants were selected on THB agar containing 100 µg/ml streptomycin. Experiments were performed in triplicates and repeated three times. The means ± SD of one typical experiment are shown.