Fig. 6. Influence of Csu pili, type IV pili, and AIS_2337 on systemic spread of intraperitoneal infection in an experimental mouse model.

A The plotted data show the percentage of mice that survived at different time points after intraperitoneal infection (IP) using the inoculum dose of 10⁷ bacteria per mouse. In total, 6 mice were infected with each isolate. B Bar chart diagram showing total neutrophil count in the blood withdrawn through heart puncturing from mice after 18 h of infection with wild type cells and transposon insertion mutants of the hypervirulent strain AB5075. C Bar chart diagrams showing relative colonization of bacteria into lungs, liver and spleen of mice, sacrificed after 18 h of intraperitoneal infection and measured upon CFU counting of bacterial colonies on LB agar plates. CFU counts shown here represent CFU per millilitre of homogenized tissue. Each experiment was performed with 6 mice. D, E Effect of the ΔpdeB mutation on systemic infection by the low virulent A. baumannii strain 17978 in the BALBc mouse model using an inoculum dose of 10⁷ bacteria per mouse for intraperitoneal infection. D Bar chart diagram showing total neutrophil count in blood of mice infected with A. baumannii 17978 wild type and ΔpdeB mutant, using samples withdrawn after 18 h. E Bar chart diagram showing the relative colonization of bacteria in the lungs, liver, and spleen of mice after 18 h of intraperitoneal infection and measured upon CFU counting of bacterial colonies on LB agar plates. Each experiment was performed with 6 mice. Error bars show mean ± SD. Statistical significance is indicated by p value that was measured by non-parametric two tailed t test. A single asterisk * indicates p ≤ 0.05, two asterisks ** indicate p ≤ 0.01 and “ns” indicates non-significant difference.