FIG 5.

Ce6-aPDT is effective at preventing bacterial regrowth and biofilm reestablishment 24 h following dual treatment. Biofilms of M. catarrhalis 7169 (A), S. pneumoniae EF3030 (B), and NTHi 86-026NP (C) were exposed to a single (gray bars, open symbols) or dual (white bars, closed symbols) Ce6-aPDT treatments (total light dosage of 90 J/cm² using 10 μM Ce6). The surviving biofilm-associated bacteria were enumerated to assess viability immediately following treatment (t = 0, solid bars) or 24 h posttreatment (t = 24 h, lined bars). The dashed lines indicate the limit of detection. The data are presented as the means ± SDs, with independent replicates shown. ns, not significant; ***, P = 0.0008; ****, P < 0.0001.