FIG 3.

Loss of the electron transport chain results in significantly reduced hemolytic activity. Shown are hemolytic activities of culture supernatants of wild-type S. aureus SH1000 and derived strains (A) and USA300 and derived mutants (B). Culture supernatants were used undiluted (U) or after serial 2-fold dilutions, as indicated. The data represent the means of at least 4 independent experiments, each in triplicate. The error bars represent the standard deviations of the mean. Values that are significantly different (P < 0.05 by Student's t test) from those of the wild type at equivalent dilutions are indicated by asterisks.