The TNF-α profile of P. aeruginosa-infected mice was determined in lung homogenates at 3-, 24- and 72-hrs post-infection by ELISA. A. AES-1M elicited a rapid and significantly greater TNF-α response compared to AES-1R at 3 and 24-hr, and both responses were still at >400pg/ml at 72hr despite the absence of bacteria in lungs. B. Both PA14 and PA14hmgA elicited a rapid TNF-α response compared to control uninfected mice by three hrs post-infection however there was no significant difference between them. The significances of differences between strains were determined by ANOVA * p<0.0001 vs. AES-1R. C. Mice were infected with 10⁶ CFU of either wildtype PA14 or PA14ΔhmgA and lungs were harvested at 72-hrs post-infection. Single cells suspensions were stained and analysed by FACS. Neutrophil populations were identified based on their CD11b⁺Ly6G⁺phenotype. Total cell numbers in the lung were determined based on the number of stained cells. Infection with PA14ΔhmgA was marked by a significant increase in the number of neutrophils in the lung compared to mice infected with PA14. The significances of differences between strains were determined by ANOVA * p<0.05 vs. PA14 WT.

https://doi.org/10.1371/journal.pone.0138633.g001