FIG 2 .

Extracts of P. acnes KPA171202 conditioned medium (CM) induce S. aureus aggregation. (A) Addition of a crude extract of P. acnes KPA171202 CM to stationary-phase cultures of S. aureus grown in SSD0Fe induced aggregation; (B) HPLC fractions (denoted by elution time) of P. acnes KPA171202 CM were added to S. aureus KPL1845 cultures. The 400-nm (blue line) and 280-nm (orange line) absorbance during HPLC elution are shown. The black arrow indicates the 400-nm-absorbing HPLC peak included in the 10- to 12-min fraction. Histogram bars represent the mean S. aureus aggregation ratio for each elution fraction or sample. All data are from five independent experiments; error bars are standard errors of the means (SEM).