Bacterial dissemination into the bloodstream increases over time during pneumonia and is dependent on the ADPRT domain of ExoS.

<p>Mice were intranasally infected with PA99Sbla or PA99S(E379A/E381A)bla, and dissemination to the bloodstream was measured. The inoculum of PA99S(E379A/E381A)bla was adjusted such that equivalent CFU of this strain and PA99Sbla were recovered from the lungs at 23 hr post-infection. A) Number of bacteria in the blood. At 12, 18, or 23 hr post-infection, cardiac punctures were performed, and blood was plated for enumeration of bacteria. Each symbol represents one mouse. n ≥ 10 mice per strain. Bars indicate medians. Dotted line represents the limit of detection (0.005 CFU/μl). B) The proportion of mice with detectable bacteria in their blood. Samples were obtained as described in panel A. ND, not determined. (*, significantly different from dissemination frequency of PA99Sbla at 23 hr) C) Number of bacteria in the liver. At 23 hr post-infection, livers were removed, homogenized and plated. Each symbol represents one mouse. n = 10 per strain. Bars represent medians. Dotted line represents the limit of detection (50 CFU/liver).