Table 1.
The strains and plasmids used in this study.
Table 2.
Primers used in this study.
Fig 1.
CBB-R250-stained 2-DE protein profiles of S. mutans UA159 biofilms on polystyrene plate co-cultured without (A) and with S. gordonii DL1 (B).
The circled spot(s) are S. mutans UA159 monoculture biofilms proteins upregulated more than 1.5-fold compared to the S. mutans UA159 biofilms co-cultured with S. gordonii DL1 (A) or vice versa (B). The number of up-regulated protein was only one in S. mutans monoculture biofilm (A), whereas 46 protein spots were up-regulated in S. mutans co-cultured with S. gordonii (B). (C) The protein spot upregulated the most was No. 3633 (circled). The No. 3633 protein is indicated by arrowhead (B). Triplicate independent analysis for each sample were performed.
Fig 2.
Inhibition of the growth of S. mutans strains by S. gordonii.
(A) Inhibition of the growth of S. mutans dpr-deficient strains by S. gordonii DL1 and spxB-deficient strain. S. gordonii strains were inoculated first and grown for 24 h at 37°C in an aerobic atmosphere. Then, S. mutans strains were inoculated next to these colonizers, and the plates were incubated for 24 h (upper lane). S. gordonii and S. mutans were inoculated simultaneously on the plate and incubated for 24 h at 37°C under aerobic conditions (lower lane). (B) Inhibition of the growth of S. mutans sod-, ahpC-, dpr- ahpC, and sod double mutants by S. gordonii DL1. The culture conditions were the same as in (A).
Fig 3.
Inhibition of the growth of S. mutans strains by (A) S. mitis and (B) S. sanguinis.
S. mitis or S. sanguinis was inoculated first and grown for 24 h at 37°C in an anaerobic (anaerobic S. mit/S. san first) or aerobic (aerobic S. mit/S. san first) atmosphere. Then, S. mutans strains were inoculated next to these colonizers, and the plates were incubated for 24 h. The S. mitis or S. sanguinis strain and S. mutans were inoculated simultaneously on the plate and incubated for 24 h at 37°C under aerobic conditions (simultaneous aerobic). S. m, S. mutans; S. mit, S. mitis; S. san, S. sanguinis.
Fig 4.
The relative quantities of S. mutans sod, ahpC, and dpr genes when co-cultured with S. gordonii.
Fold expressions were shown as the ratio of S. mutans co-cultured with S. gordonii to S. mutans cultured without S. gordonii. All gene expressions were normalized to gryA. The data are expressed as the means and SDs of three experiments.
Fig 5.
S. mutans Dpr expression by Western blotting analysis.
(A) Planktonic cells. (B) Biofilm. Lane M, molecular mass markers; lane 1, S. mutans without S. gordonii; lane 2, S. mutans co-cultured with S. gordonii DL1; lane 3, S. mutans co-cultured with S. gordonii ΔspxB.
Fig 6.
Viability assay of S. mutans strains after co-inoculation with S. gordonii.
S. mutans strains were inoculated into S. gordonii pre-existing BHI medium and additionally inoculated at 37°C under anaerobic conditions for 48 h. S. mutans CFU on MS agar plates supplemented with bacitracin were counted and adjusted to CFU/well. Data are shown as the means of triplicate platings from one of two reproducible experiments. *P < 0.05.
Fig 7.
Linkage among iron, Dpr, and oxygen metabolism in S. mutans [41].