FIG 1.

Methamphetamine (METH) and sucrose stimulate S. mutans replication in vitro. The effect of METH, sucrose, or their combination on S. mutans growth kinetics was determined via Bioscreen C (A) and CFU (B) analyses. S. mutans was grown in the absence (untreated) or presence of 25 μM METH, 2% sucrose, or 25 μM METH plus 2% sucrose. For real-time spectrophotometry and cell viability assays, each time point represents the average from 16 and 5 individual measurements, respectively. Symbols (*, #, and ϕ) indicate higher proliferation rates than in the untreated, 25 μM METH, or 2% sucrose group, respectively. Each symbol denotes P value significance (P < 0.05) calculated by ANOVA and adjusted by the use of Tukey’s multiple-comparison test. These experiments were performed twice, with similar results obtained each time.