Chlamydiota

Chlamydiota is a bacterial phylum whose members have distinctive developmental cycles; many species replicate only inside host cells, including pathogens that cause chlamydial infections.

Elementary body: The small, infectious, metabolically limited form of a chlamydial cell that initiates infection. This extracellular form carries infection between host cells.
Chlamydia trachomatis: A bacterial species that causes trachoma, genital infections, and other chlamydial diseases in humans. It is the best-known human pathogen in the phylum.
Bacterium: A single-celled organism whose cells lack a membrane-bound nucleus. Chlamydiota belongs to this broad domain of cellular life.
Halberstaedter and von Prowazek: Scientists who described intracellular inclusions in trachoma-infected cells in 1907. Their observations helped establish the infectious agent’s intracellular nature.
Reticulate body: The larger, replicating form of a chlamydial cell found inside a host-cell inclusion. After entry, elementary bodies transform into this dividing form.
Chlamydia pneumoniae: A bacterial species that infects the human respiratory tract and can cause pneumonia. It illustrates respiratory disease caused by a member of Chlamydiota.
Gram-negative bacteria: Bacteria that retain the counterstain in Gram staining and have a characteristic cell-envelope architecture. Chlamydial cell envelopes share key features with Gram-negative bacteria despite atypical staining.
Stanislaus von Prowazek: A zoologist and microbiologist who studied trachoma and other infectious diseases. His work contributed to early recognition of chlamydial inclusions.
Chlamydial inclusion: A membrane-bound compartment inside a host cell where chlamydiae develop and replicate. The developmental cycle unfolds within this modified host-cell compartment.
Chlamydia psittaci: A bacterial species carried by birds that can cause psittacosis in humans. Its animal reservoir shows that chlamydial infections can cross species.

Linked from 1 page

Bacterial phylumBroader topic: It shows that a phylum can include lineages defined by specialized host dependence.