BCL2 and infection: ΔOmp31 triggered more apoptosis at 2-24h post-infection. ΔOmp31 increased the expression of Caspase3, Caspase8 and Caspase9 at 4h post-infection, decreased the expression of Bcl-2 at 8, 12, and 24h post-infection, increased Bax expression at 2, 4, 8, 12, and 24 h post-infection, and increased Cyt c concentration at 4, 8, 12, and 24 h post-infection.