FIGURE 3.

Responses of the Streptococcus mitis sigX reporter in the type strain to CSP. A pre-culture of MI055 at OD₆₀₀ 0.5 was diluted 1:100 in C+Y_{Y B} and grown until OD₆₀₀ 0.04 at 37°C in 5% CO_2. At time_0, the lag phase cell culture (OD₆₀₀ 0.039) was treated with 300 nM CSP and distributed into 200 μL aliquots that were further exposed to 150 ng mL^-1 amplicon donor DNA of 7 kb (aRJ20) at different time points. 20 U mL^-1 DNase I were added after 30 min of exposure to DNA and the culture was incubated in air at 37°C for additional 30 min. The % of CFU containing Erm^R transformants was determined by plating on blood plates with or without 20 μg mL^-1 erythromycin. (A) Growth curves with and without CSP, measured as OD₆₀₀. (B) Induction of sigX and transformation. The results are average from 3 triplicates and representative of two independent experiments. Error bars represent the standard error of the mean.