Dispersal of established biofilms by anti-rsPilA and anti-PE-PilA antibodies. Adult chinchillas (n = 6) were immunized with rsPilA or the PE-PilA fusion protein, and sera were collected 10 days after the third immunization and pooled. NTHi biofilms of three different strains (86-028NP, 1714, 1128) were allowed to form overnight in the wells of 8-well chambered glass slides. Immunized or naive (control) serum pools were added to the culture medium after the biofilms were established. After overnight incubation, the biofilms were fixed and then viewed by confocal scanning microscopy. Images were rendered as orthogonal projections to show a top-down view (to depict the relative spatial distribution of the biofilm within the x-y planes), as well as a side view (to depict the relative biofilm height within the z plane) (A to I), and analyzed with COMSTAT software to evaluate biofilm thickness (J) and total biomass (K). Bars, 20 μm. P values are for immune sera compared with the control. ****, P < 0.0001.