Compared to the WT strain, the ΔvipA1 mutant significantly elevated IL-1β mRNA levels at 1 h (P < 0.05) and 4 h (P < 0.0001) post-infection and increased both IL-8 and IL-6 mRNA levels at 4 h (P < 0.001; Fig. 7). Here, IL6 is linked to infection.