Emended description of the order Chlamydiales, proposal of Parachlamydiaceae fam. Nov. and Simkaniaceae fam. Nov., each containing one monotypic genus, revised taxonomy of the family Chlamydiaceae, including a new genus and five new species, and standards for the identifications of organisms. - Everett,K.DE.; Bush,R.M.; Andersen,A.A. (Int J Syst Bactiriol, 1999)