Blood agar plates

The cultivation conditions for these strains have been described [15 ,16 (link),17 (link),18 (link)]. Briefly, S. mitis/oralis strains were grown in Bacto Brain Heart Infusion (BHI) medium, BHI + 2 µg/mL D-Glucose (BHI + glucose), or on blood agar plates (VWR Scientific Radnor, PA, USA) in selected studies. Bacterial pre-cultures were inoculated (1:10) from overnight cultures into 50 mL of BHI in 50 mL conical tubes and incubated at 37 °C, without shaking, for 4 h. These exponential-growth-phase pre-cultures were collected by centrifugation at 4000 rpm and 22 °C and suspended in 1 mL of culture medium. Primary cultures were inoculated into 50 mL (BHI + glucose) with or without OXA in 50 mL conical tubes to an absorbance at 600 nm (A₆₀₀) of 0.16 and incubated at 37 °C. Cultures were mixed by inversion every 30 min prior to sampling. The A₆₀₀ and pH were recorded every 30 min for 5 h.

For selective metabolic and biochemical assays below, study isolates were grown in BHIB supplemented with 2 µg/mL D-glucose (BHI + glucose) or on blood agar plates (VWR Scientific, Radnor, PA, USA). For all studies, S. oralis pre-cultures were inoculated (1:10) from overnight cultures into 50 mL of BHI in 50 mL conical tubes and incubated at 37 °C without shaking for 4 h.