Chlamydiaceae

Microorganisms belonging to the Chlamydiaceae family are Gram-negative, obligatory intracellular bacteria involved in diseases affecting both animals and humans.

The Chlamaydiaceae family traditionally contained a single genus, Chlamydia (Bergey’s Manual of Systematic Bacteriology vol.1, 1984) but in 1999 a new genus, Chlamydophila, was added based on 16S rRNA and 23S rRNA sequence’s similarity (Everett et al. in 1999). Furthermore, other five new species were proposed by Everett. However, the use of the new genus name was debated within the scientific community and for this reason the edition of the Bergey’s Manual (vol.4, 2011) considers the genus Chlamydia the only genus and the five additional species are classified within this genus. Since the taxonomy of the family Chlamydiaceae is currently under consideration, and species with the name Chlamydophila felis, Chlamydophila pecorum and Chlamydophila abortus have been widely and validly published, the subdivision into two genera Chlamydia and Chlamydophila has been retained in this collection until 2013. From 2014, only the genus Chlamydia is used.

Currently, the genus Chlamydia encompass 10 recognised species: C. abortus, C. avium, C. felis, C. gallinacea, C. pecorum, C. pneumonia, C. psittaci, C. poikilotherma, C. suis, C. trachomatis. Other species have been proposed in several publications but not yet accepted as such.