IL6 and infection: Significantly higher levels of IL-6 were seen in cells infected by clinical isolates B12 (846 pg ul−1) and D1 (998 pg ul−1) when compared to the cells infected by PAO1 (530 pg ul−1) and PA14 lab strains (334 pg ul−1) at 24 h post-infection (One-way ANOVA, Tukey post-hoc, P<0.05) (Fig. 3).