FIG 1.

Formation of pneumococcal biofilm consortia by invasive strains. S. pneumoniae S6B (3875), S19F (5131), or S23F (8064) was inoculated alone or coinoculated with the indicated strain into 24-well plates (A) or immobilized human pharyngeal cells (B) and incubated for 8 h, after which biofilms (one strain) and biofilm consortia (mixtures) were harvested and DNA was extracted. DNA was used as the template in qPCRs targeting the pan-pneumococcus lytA gene, and the number of genome equivalents per milliliter was calculated. The error bars represent the standard errors of the means and were calculated using data from at least three independent experiments.