TNF and infection: It was found that infection by all sensitive and resistant strains induced significant up-regulation in the expression of anti-apoptotic (bcl2 and rb1), chemokine (IL-8 and MCP-1), and pro-inflammatory cytokine (IFN-γ and TNF-α) genes, whereas significant down-regulation was observed in pro-apoptotic (bad and bax) and anti-inflammatory (IL-10) genes 24 and 48 hr post-infection.