PTGS2 and infection: As illustrated in Figure 6, COX-2 mRNA expression was upregulated in HKDM-WT compared to uninfected HKDM and in HKDM-∆EseN mutant compare to HKDM-WT during all times of post-infection, but significantly only at 1 h, 3 h, and 5 h of post-infection.