Figure 2.
Biofilm pneumococci are less virulent and elicit a weaker immune response than their planktonic counterparts. (A) Bacterial titers in the lungs and blood of BALB/c mice challenged intratracheally with 105 CFU of planktonic or biofilm derived S. pneumoniae (each square = individual mouse; n = 6–8). From: Sanchez et al. (2011b). (B) Percentage of planktonic and biofilm derived S. pneumoniae that attached and invaded Detroit-562 pharyngeal cells in vitro. Percentages were calculated from the total inoculum. (C) Cytokine levels in nasopharyngeal lavage fluid (NALF) of colonized mice. Mice were challenged with wild type (WT) and PsrP-deficient (ΔpsrP−) S. pneumoniae and NALF collected 7 days later. Note that ΔpsrP− does not form biofilms during colonization (n = 5). Panels (B,C) from: Blanchette-Cain et al. (2013). Asterisks denote a statistically significant difference (P < 0.05).