Three salient observations were made (Figure 4): 1) Although reduced induction of all cytokine transcripts tested was observed upon infection with both hyperinfectious and conventionally virulent strains grown in LB versus LPM pH 5.5 medium (P<0.05), only hyperinfectious strains exhibited significant reduced stimulation of IFN-β, IL-1β, and IL-6 transcript levels at the 2 h infection time point (2.5- to 3.5- fold; P<0.05). Here, IFNB1 is linked to infection.