FIG 2.

Viability of biofilm-detached bacteria (hatched bars) was assessed by evaluating surviving CFU in the surrounding saline supernatant following aPDT of M. catarrhalis 7169 (Mcat), S. pneumoniae EF3030 (Spn), and NTHi 86-026NP (NTHi) biofilms (solid bars). There were no surviving bacteria (≤10 CFU) detected in the surrounding saline following Ce6-aPDT of the biofilms compared to the untreated control groups (≥10⁶ CFU), indicating that bacteria that detach from the biofilms in response to aPDT are not viable. The dashed line indicates the limit of detection. The data are presented as the means ± SDs, with independent replicates shown. ****, P < 0.0001.