FIG. 1.

Comparison of S. aureus ISP479C and ISP479R growth kinetics in vitro. Log-phase organisms were dually inoculated (10³ CFU of each strain) into 10 ml of BHI broth, and the cultures were incubated on a rotary shaker (for aeration) at 37°C. At selected time points, aliquots were quantitatively cultured on BHI agar with or without erythromycin (10 μg/ml; as described in Materials and Methods). Data points represent the mean values from two independent experiments performed in duplicate. In no case was the deviation from the mean greater than 0.2 log CFU/ml; error bars were intentionally excluded to improve clarity. These results mirrored those of identical dual-culture experiments performed with nutrient or Trypticase soy broth (see Materials and Methods). These results were not significantly different from those for either organism cultured alone (data not shown).