Fig 1. Interactions of Streptococcus pneumoniae with pleural mesothelial cells in vitro.

A) Association: monolayers of Met-5A cells were infected with various MOI of Streptococcus pneumoniae strain D39. Total associated (defining adherent and internalised bacteria combined) bacteria were counted following saponin lysis of infected monolayers over time. The data are representative of >3 independent experiments; the symbols represent mean adherence and the error bars the standard deviations of wells infected in triplicate. B) Invasion: monolayers of Met5A cells were infected for 9h with MOI 0.025 of D39 and intracellular bacteria were recovered after gentamicin treatment and saponin lysis. Monolayers were also pre-treated with cytochalasin D prior to bacterial infection. The bars represent the mean bacterial cfu of three independent experiments and the error bars the standard error of the means.