Fig. 3.
Assays for E. coli TG1 biofilm levels and phage counts after 24 h with no treatment or with treatment with phage T7wt, phage T3wt, non-DspB-expressing phage T7control, or DspB-expressing phage T7DspB. Error bars indicate SEM. (A) Mean absorbance (600 nm) for n = 16 biofilm pegs stained with 1% CV, solubilized in 33% acetic acid, and diluted 1:3 in 1× PBS (50). (B) Mean cell densities [log10(CFU per peg)] for n = 12 biofilm pegs. Pegs treated with T7DspB resulted in a 3.65 log10(CFU per peg) reduction in viable cells recovered from E. coli biofilm compared with untreated biofilm. (C) Mean phage counts [log10(PFU per peg)] recovered from media in n = 3 microtiter plate wells (wells) or sonication of n = 3 biofilm pegs (biofilm), as indicated, after 24 h of treatment with initial inoculations of 103 PFU per well. Both T7control and T7DspB showed evidence of replication with phage counts obtained from the microtiter plate wells or with phage counts recovered from the biofilms after sonication.