Lung inflammatory response in susceptible A/J and resistant C3H/HeOuJ <i>P</i>. <i>aeruginosa</i>-infected mice.

<p>The number of neutrophils (<b>A</b>), macrophages (<b>B</b>), lymphocytes (<b>C</b>) and epithelial cells (<b>D</b>) recruited in the airways were determined in the BALF from A/J (n = 12) (blue bar) and C3H/HeOuJ (n = 12) (green bar) mice by cytospin after 6, 12 and 18 hours of <i>P. aeruginosa</i> infection with 5×10⁶ CFU of AA2 clinical isolate. Bars represent mean values and the error bars the standard error of the mean (SEM). The data are pooled from two independent experiments. Statistical significance by Mann-Whitney U test is indicated: *p<0.05, **p<0.01, ***p<0.001.</p

Histopathology in susceptible A/J and resistant C3H/HeOuJ <i>P</i>. <i>aeruginosa</i>-infected mice.

<p>The lungs of A/J (<b>A–D</b>) and C3H/HeOuJ (<b>E–H</b>) were stained with H&E (<b>A–C, E–H</b>) and in immunofluorescence with specific antibody against <i>P. aeruginosa</i> (red) (<b>D, H</b>). Counterstaining was performed with 49,6-Diamidino-2-phenylindole dihydrochloride (DAPI) (blue). After time course analysis, extensive infection and inflammation were visible in murine lungs with major differences between A/J and C3H/HeOuJ. Arrows indicate aggregates of lynphocytes infiltrates. Bars, 200 µm for H&E images, 100 µm for immunofluorescence images. Severity of lesions and lung involvement was scored as reported in <b>Fig S4</b>.</p

<i>P. aeruginosa</i> load and leukocytes recruitment in BALF and lung of A/J and C3H/HeOuJ mice.

<p>A/J (n = 12, for each time) and C3H/HeOuJ (n = 12, for each time) mice were challenged with 5×10⁶ CFU of AA2 clinical stain and analysed during a time course post-infection. Bacterial loads in the BALF+Lung (<b>A</b>), BALF (<b>B</b>) and lung (<b>C</b>) and were counted at 6, 12 and 18 hours in surviving mice. Dots represent CFUs in individual mice and horizontal lines represent median values reported in log scale. Total leukocytes were analyzed in BALF of <i>P. aeruginosa</i> infected mice (<b>D</b>). Bars represent median values and the error bars indicate the standard error of the mean (SEM). Blue is referred to A/J and green to C3H/HeOuJ. The data are pooled from two independent experiments. Statistical significance by Mann-Whitney U test is indicated: **p<0.01, ***p<0.001, ****p<0.0001.</p

Survival, body weight and mean survival time after <i>P. aeruginosa</i> infection in inbred mouse strains.

<p>A/J (n = 22), BALB/cJ (n = 9), BALB/cAnNCrl (n = 8), BALB/cByJ (n = 12), C3H/HeOuJ (n = 26), C57BL/6J (n = 10), C57BL/6NCrl (n = 15), DBA/2J (n = 12), and 129S2/SvPasCRL (n = 12) mice were inoculated with 5×10⁶ CFU of <i>P. aeruginosa</i> clinical isolate AA2, and monitored for survival (<b>A</b>) and weight change for a period of seven days after infection (<b>C, D</b>). In addition, mean survival time was calculated based on the survival curve (<b>B</b>). Bar represent mean values and the error bars the standard error of the mean (SEM). The data are pooled from two to four independent experiments. Statistical significance by Mantel-Cox test for survival (<b>A</b>), One- way ANOVA with Bonferroni's Multiple comparison test (<b>B</b>) for mean survival time and Two-way ANOVA with Bonferroni's Multiple comparison test (<b>C, D</b>) is reported in <b><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0106873#pone.0106873.s005" target="_blank">Table S1</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0106873#pone.0106873.s007" target="_blank">S3</a></b>.</p