Fig 11.

Correlation between colonization-associated pneumococcal virulence determinants and biofilm formation on epithelial cells. Biofilms were formed on glass or paraformaldehyde-fixed NCI-H292 cells by S. pneumoniae D39 and D39 mutant strains lacking PspA, PspC, autolysin (LytA), or pneumolysin (Ply). Biofilm architecture was visualized by scanning electron microscopy after 48 h on glass and epithelial cells. (A) Forty-eight-hour biofilm development on abiotic surfaces. Insets show 20-fold-increased magnifications of parts of the field. (B) Forty-eight-hour biofilm formation over a prefixed epithelial cell substratum. Insets show 20-fold-increased magnifications of parts of the field.