Fig 5.

Comparative cell-killing assay in planktonic cells and biofilms of A. actinomycetemcomitans. To determine the efficacy of DAS treatment of both planktonic cells and A. actinomycetemcomitans biofilms, the cells were grown on a plastic coverslip for 48 h at 37°C. The biofilms were washed with PBS and then treated with DAS (0.01 μg/ml) for 2 h. To determine the efficacy of DAS treatment of A. actinomycetemcomitans biofilms, cells were scraped from the coverslip after treatment with DAS, serially diluted, and plated on an AAGM agar plate. For the planktonic cell-killing assay, the biofilms were scraped from the coverslip, treated with DAS for 2 h in a 1.5-ml microcentrifuge tube, serially diluted, and plated on AAGM agar for enumeration after 48 h. Data represent means ± SE and significantly differ from control results (P < 0.01).