IL6 and infection: The prolongation of the infection time (up to 24 h) exacerbated the bacterial pro-inflammatory effects, especially in the case of ST239, whose IL-6 mRNA expression levels were significantly higher than those observed in cells in the absence of bacteria (p < 0.001) as well as for ST30 (p < 0.05) and the remaining MRSA strains (p < 0.001 vs. all of them) (Figure 3B).