Figure 4.

Alpha toxin protein expression in Staphylococcus aureus nasal isolates. In vitro AT expression was measured in the supernatants of overnight S. aureus cultures grown in TSB. Each sample was tested in duplicate. (a) For subjects who were S. aureus positive at baseline, changes of AT expression levels from the baseline were summarised in mean and standard deviation for each treatment group at each visit time point. The dashed line at 0 represents no change. (b) For subjects who were S. aureus negative at baseline but tested positive at postinfusion visits, the AT expression levels were compared with isolates from baseline. The dashed lines are the LLOQ (1 μg mL⁻¹) and the upper limit of quantitation (ULOQ) (10 μg mL⁻¹), where 10.5, 0.5 and 0 μg mL⁻¹ were used for measurements greater than the ULOQ, positive (POS), or below the LLOQ, and negative, respectively.