FIG 6.

Co-culturing of S. mutans with V. parvula leads to enhanced biofilm formation. Cultures were grown for 24 h, 72 h, or 1 week in an anaerobic chamber prior to processing the biofilms and measuring the pH of the supernatants. Biofilms were formed in BB+ broth with 0.5% sucrose (A) or artificial saliva with 0.5% sucrose (B to D) (29). Bacteria were inoculated at a starting OD₆₀₀ of 1.0 (A, B, and D) or 0.1 (C) by using S. mutans ATCC 25175 and V. parvula ATCC 10790. (D) S. mutans and V. parvula clinical isolates from patient 4 (teeth 8 and 9) were also assessed for biofilm formation and acidification. *, P ≤ 0.05 by Student’s t test.