FIGURE 5.

Lactoferrin eradicates preformed Streptococcus pneumoniae biofilms in nasopharynx cells. S. pneumoniae (spn) strain TIGR4 (7.5 × 10⁴ CFU/ml) was inoculated in a 24-well plate containing Detroit cells and plates were incubated for 4 h at 37°C with 5% CO₂. Planktonic cells were removed and biofilms were washed and then untreated (A) or treated with bovine Lactoferrin bLF, 40 and 80 μM (B,C, respectively) for 6 h. Treated biofilms were slowly washed once with PBS, fixed with 2% P-formaldehyde, and stained with Wheat germ agglutinin (WGA) for the cell membrane, antibody serotype-specific polyclonal for S. pneumoniae and DAPI for DNA. Confocal images with close up of 10 μM were obtained using an Olympus FV1000 confocal microscope and were analyzed with ImageJ version 1.49k. Arrows indicate the decrement of pneumococcal cells in biofilms.