Chlamydiales

The bacterial order Chlamydiales includes only obligately intracellular bacteria that have a chlamydia-like developmental cycle of replication and at least 80% 16S rRNA or 23S rRNA gene sequence identity with other members of Chlamydiales. Chlamydiales live in animals, insects, and protozoa.

Currently, the order Chlamydiales includes the families Chlamydiaceae, Simkaniaceae, and Waddliaceae, which have Gram-negative extracellular infectious bodies (EBs), and Parachlamydiaceae, which has variable Gram staining of EBs. The family Rhabdochlamydiaceae has been proposed.

Taxonomy
The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI)


 * Family "Actinochlamydiaceae" Steigen et al. 2013
 * ?"Ca. Actinochlamydia" Steigen et al. 2013
 * Family "Criblamydiaceae" Thomas, Casson & Greub 2006
 * "Criblamydia" Thomas, Casson & Greub 2006
 * "Estrella" Thomas et al. 2006
 * Family Chlamydiaceae Rake 1957 ["Clavichlamydiaceae" Horn 2011 ]
 * "Ca. Amphibiichlamydia" Martel et al. 2012
 * Chlamydia Jones et al. 1945
 * Chlamydiifrater Vorimore et al. 2023
 * Chlamydophila Everett, Bush & Andersen 1999
 * "Ca. Clavichlamydia" corrig. Karlsen et al. 2008
 * ?"Ca. Medusoplasma" Viver et al. 2017
 * Family Parachlamydiaceae Everett, Bush & Andersen 1999
 * ?"Ca. Mesochlamydia" Corsaro et al. 2012
 * ?"Ca. Metachlamydia" Corsaro et al. 2010
 * Neochlamydia Horn et al. 2001
 * Parachlamydia Everett, Bush & Andersen 1999
 * "Ca. Protochlamydia" Collingro et al. 2005
 * "Ca. Rubidus" Pagnier et al. 2015
 * Family Rhabdochlamydiaceae Corsaro et al. 2009
 * ?"Ca. Acheromyda" Davison & Hurst 2023
 * ?"Ca. Renichlamydia" Corsaro & Work 2012
 * "Ca. Rhabdochlamydia" Kostanjsek et al. 2004
 * ?"Ca. Sacchlamyda" Davison & Hurst 2023
 * Family Simkaniaceae Everett, Bush & Andersen 1999
 * ?"Ca. Amphrikana" Davison & Hurst 2023
 * ?"Ca. Fritschea" Everett et al. 2005
 * "Ca. Neptunochlamydia" Pizzetti et al. 2016
 * Simkania Everett, Bush & Andersen 1999
 * ?"Ca. Syngnamydia" Fehr et al. 2013
 * Family Waddliaceae Rurangirwa et al. 1999
 * Genus Waddlia Rurangirwa et al. 1999