At the highest concentration of bacteria tested (MOI = 10), we found that synthesis of IL-8 in infant primary cultures were significantly reduced following infection with cagPAI mutant strains (both cagY and cagA) when compared to the wildtype (WT) strain (p<0.01 WT vs cagY, WT vs cagA) (Fig 4A). Here, CXCL8 is linked to infection.