Chlamydia psittaci is an obligate intracellular pathogen that can cause zoonosis. Persistent C. psittaci infection can inhibit apoptosis in host cells, thus extending their survival and enabling them to complete their growth cycle. In this study, the antiapoptotic effects of persistent C. psittaci infection, induced by treatment with IFN-γ, were found to be associated with both the death receptor and the mitochondrial pathways of apoptosis. These effects were mediated by Bcl-2 family members, as evidenced by the decreased expression of proapop...