CXCL8 and infection: At 2 hours post-infection all strains induced similar amounts of IL-8 protein in the range of 600 pg/ml, with the exception of strains P12ABF or P12ABFF which exhibited significantly decreased levels (400 pg/ml) and P12ABFFF, for which levels of IL-8 protein were negligible and comparable to those observed for uninfected control cells (Figure 2B).