FIG 8.

The ΔhrtB S. aureus strain is variably sensitive to exposure to toxic MPs. WT and ΔhrtB S. aureus strains were cultured in TSB in the presence or absence of 10 μM nonmetalated PPIX or various MPs. Growth was monitored at 24 h postinoculation through measurement of OD₆₀₀. Growth assays were performed at least three times on separate days. Additionally, technical triplicates were performed on each day. Error bars represent SEM of the biological replicates. The asterisk (*) indicates P < 0.05 as determined by a two-tailed Student's t test.