Chlamydiae
From Free net encyclopedia
{{Taxobox
| color = lightgrey
| name = Chlamydiae
| regnum = Bacteria
| phylum = Chlamydiae
| ordo = Chlamydiales
| subdivision_ranks = Genera
| subdivision =
Chlamydia
Chlamydophila
Parachlamydia
Simkania
Waddlia
}}
The Chlamydiae are a group of bacteria, all of which are intracellular parasites of eukaryotic cells. Most described species infect mammals and birds, but some have been found in other hosts, such as amoebae. Originally they were treated as the single genus Chlamydia, but now several different genera are recognized. They are related to certain other bacterial groups, notably the Thermomicrobia, but are generally given their own phylum.
Chlamydiae have a life-cycle involving two distinct forms. Infection takes place by means of elementary bodies (EB), which are metabolically inactive. These are taken up within a cellular vacuole, where they grow into larger reticulate bodies (RB), which reproduce. Ultimately new elementary bodies are produced and expelled from the cell.
There are three main species of chlamydiae that infect humans:
- Chlamydia trachomatis, which causes the eye-disease trachoma and the sexually transmitted infection chlamydia;
- Chlamydophila pneumoniae, which causes a form of pneumonia;
- Chlamydophila psittaci, which causes psittacosis.da:Chlamydiae