[Early events in chlamydial infection of host cells]

Chlamydiae, gram-negative, obligate intracellular bacteria, are major pathogens worldwide, causing several diseases including trachoma, respiratory diseases and sexually transmitted disease. Penetration of chlamydiae to epithelial cells, the environment which supports their growth and survival, leads to various events that begin with changes to the bacteria-containing vacuole, allowing for its progression from the endosomal to the exocytic pathway. The changes include fusion with vesicles carrying glycerophospholipids and sphingolipids and originating in the endoplasmic reticulum (ER) and the Golgi apparatus. The bacteria then reproduce in the inclusion vesicles. In this survey we describe the chlamydial life cycle and review recent reports on early intracellular events in chlamydial infection. While antibiotics currently recommended for treatment of chlamydial infections interfere with bacterial macromolecular synthesis, newer forms of treatment may be developed based on our increasing understanding of chlamydial manipulation of intracellular processes. This manipulation, described in this article on early intracellular events in chlamydial infection, enables these pathogens to escape destruction in the endosomal compartment and begin replication in the target cell.