Skip to Content


Pronunciation: kla-mid′ē-ā′sē-ē

Definition: A family of the order Chlamydiales (formerly included in the order Rickettsiales) that includes the agents of the psittacosis-lymphogranuloma-trachoma group. The family contains small, coccoid, gram-negative bacteria that resemble rickettsiae but that differ from them significantly by possessing a unique, obligately intracellular developmental cycle; intracytoplasmic microcolonies give rise to infectious forms by division. The classification of these organisms previously was in a state of flux, but they are now placed in a single genus, Chlamydia, the type genus of the family.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

© Copyright 2018 Wolters Kluwer. All Rights Reserved. Review date: Sep 19, 2016.