Fig. 6.

RNA III expression in clinical isolates grown in serum. S. aureus clinical isolates cultured in TSB, CS, and CS with 300 μM FeCl₃ were collected at the exponential phase. The expression of RNA III was determined by quantitative PCR by the method described in Materials and Methods. The data shown represent means and SD of measurements performed in triplicate. The asterisks indicate significant increases compared with TSB as determined by Student's t test: *, P < 0.05; **, P < 0.01. The pluses indicate significant decreases compared with the medium with no addition of FeCl₃ as determined by Student's t test: +, P < 0.05.