The Parachlamydia acanthamoeba,including eight species,was officially named in 1999as a new type of Chlamydia.The replication cycle involves elementary body,reticulate body and crescent body.As an acanthamoeba endosymbionts,the Parachlamydia acanthamoeba can be isolated and cultured.The research about etiology of Parachlamydia acanthamoeba provides important clues and means for the clinical detection and prevention.In this paper,the research progress ab...