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. 2010 Apr 12;78(6):2754–2767. doi: 10.1128/IAI.01370-09

FIG. 6.

FIG. 6.

Effect of supplementing the medium with peptides or sugars on the expression of virulence genes regulated by CvfA. The wild-type (WT) strain (HSC5spc) and CvfA− mutant strain (ΩCvfA strain) were used. (A) Glucose influences the expression of emm, ska, and cfa, and peptides influence the expression of speB through CvfA. The amounts (Amt) of transcripts of the genes encoding M protein (emm), streptokinase (ska), CAMP factor (cfa), and streptococcal pyrogenic exotoxin B (speB) in the CvfA− mutant were determined by real-time RT-PCR and expressed relative to those of the wild type (CvfA−/WT). The cells were grown to the stationary phase (8 h postinoculation) in chemically defined medium containing glucose (0.05% or 1.0% [wt/vol]) as a carbohydrate source and/or dialyzed proteose peptone (1.0% [wt/vol]) as a supplemented peptide source. (B) Supplementation with fructose, galactose, or mannose gave results similar to the results of supplementation with glucose on the expression of the emm and speB genes regulated by CvfA. The amounts of transcripts of the genes encoding M protein (emm) and streptococcal pyrogenic exotoxin B (speB) in the CvfA− mutant were determined by real-time RT-PCR and expressed relative to those of the wild type (CvfA−/WT). The cells were grown to the stationary phase (8 h postinoculation) in chemically defined medium containing glucose (0.05% or 1.0% [wt/vol]), fructose (1.0% [wt/vol]), galactose (1.0% [wt/vol]), or mannose (1.0% [wt/vol]) as a carbohydrate source. Abbreviations: Glc, glucose; Gal, galactose; Fru, fructose; Man, mannose; dPP, dialyzed proteose peptone.