IL1B and infection: At 4 h post-infection, PA14 and B12 infected cells produced significantly higher levels (39 and 54 pg ul−1, respectively) of IL-1β than PAO1 and D1 infected cells (5 and 3 pg ul−1, respectively) (One-way ANOVA, Tukey post-hoc, P<0.05) (Fig. 3).