FIG 3.
Expression of pla increases during progression of pneumonia independent of presence in a biofilm. Cross sections of lungs from mice infected with strain CO92 carrying the Ppla-GFP reporter (green) and pGEN-RFP plasmid (red) were stained with DAPI (blue) and imaged by confocal microscopy. (A) The large image was generated in NIS Elements similarly to infections with the Pcrp-GFP strain. Magnified images of boxed areas (a to d) highlight the heterogeneity in expression patterns of pla within the larger lesion. (B) Violin plots displaying the relative expression of pla as a ratio of GFP to RFP, quantified in individual cells combined from the lung lesions of at least three mice at each time point, across two independent infection experiments at 36, 48, and 72 hpi. Horizontal lines within the violins represent the 25th percentile, median, and 75th percentile. Aggregates were also imaged and analyzed separately. (C) Expression of pla in individual cells as a function of neighboring bacterial cell density.