FIG 2.
Binding metrics on living S. aureus as determined by AFM. Box-and-whisker plots of frequency of binding (A), adhesion force (B), rupture force (C), and energy or work of binding (D) for a fibronectin-coated probe on S. aureus cells grouped according to clonal complex (CC5 versus CC45) and persistence in human infection (PB versus RB) are shown. The frequency of binding (A) is defined as the incidence of observing a binding event (like those shown in Fig. 1), where a value of 0 represents no observed binding, and a value of 1 means that all spectra exhibited a binding force signature. All other attributes (adhesion force, rupture force, and energy/work) are defined in Fig. 1. For panels B, C, and D, force is in nanonewtons (10−9 N) and energy/work is in attojoules (10−18 J). Box ends represent the first and third quartiles. Whisker ends represent the 9th and 91st percentiles. A Student t test was used to determine P values.