FIG 6.

qPCR primers and mRNA levels of virulence factors produced by P. acnes biofilms challenged with an elevated concentration of free iron following 8 days of growth. (A) Primers used for qPCR analysis of P. acnes virulence factors. (B) mRNA levels in 8-day-old biofilms of P. acnes VP1 challenged with 0.5 mM iron for 50 min. Expression levels are compared to those in untreated 8-day-old P. acnes biofilms. Error bars represent ±1 standard deviation. *, statistically significant. All experiments were performed in triplicate.