Species Chlamydia trachomatis

Name: Chlamydia trachomatis corrig. (Busacca 1935) Rake 1957 (Approved Lists 1980)

Category, proposed as: species, comb. nov.

Basonym: "Rickettsia trachomae" Busacca 1935

Etymology: tra.cho’ma.tis. Gr. neut. n. trachysma, a roughness; N.L. neut. n. trachoma, the disease trachoma; N.L. gen. neut. n. trachomatis, of trachoma

Pronunciation (Latin), gender: k^hla-MY-di-a tra-K^HO-ma-tis, feminine

Type strain: A/Har-13; ATCC VR-571B; Har-13; pC

Conduct genome-based taxonomy at

16S rRNA gene: D89067 Analyse FASTA

Effective publication: Rake G. Family II. Chlamydiaceae Fam. Nov. In: Breed RS, Murray EGD, Smith NR (eds), Bergey's Manual of Determinative Bacteriology, seventh edition, The Williams & Wilkins Co, Baltimore, 1957, p. 957-968.

IJSEM list: Skerman VBD, McGowan V, Sneath PHA. Approved lists of bacterial names. Int J Syst Bacteriol 1980; 30:225-420.

Nomenclatural status: validly published under the ICNP, lectotype

Taxonomic status: correct name (and explicitly recommended for medical use)

Risk group: 2

• Synonyms:

  • Name	Kind
    "Rickettsia trachomatis" corrig. Busacca 1935	homotypic synonym, not validly published, basonym of name in Approved Lists
    "Rickettsia trachomae" Busacca 1935	homotypic synonym, inaccurate spelling

• Emendations:
  • Everett et al. 1999 Everett KD, Bush RM, Andersen AA. 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 identification of organisms. Int J Syst Bacteriol 1999; 49:415-440. 🇺🇸 Anonymous. Notification list. Notification that new names and new combinations have appeared in volume 49, part 2 of the IJSB. Int J Syst Bacteriol 1999; 49:937-939.
  • García-López et al. 2019 Garcia-Lopez M, Meier-Kolthoff JP, Tindall BJ, Gronow S, Woyke T, Kyrpides NC, Hahnke RL, Goker M. Analysis of 1,000 Type-Strain Genomes Improves Taxonomic Classification of Bacteroidetes. Front Microbiol 2019; 10:2083. 🇩🇪 Oren A, Garrity GM. List of changes in taxonomic opinion no. 32. Notification of changes in taxonomic opinion previously published outside the IJSEM. Int J Syst Evol Microbiol 2020; 70:4061-4090.

• Notes:
  • 🥇 Nomenclatural type of the genus Chlamydia Jones et al. 1945 (Approved Lists 1980). Publication: Jones H, Rake G, Stearns B. Studies on lymphogranuloma venereum. III. The action of the sulfonamides on the agent of lymphogranuloma venereum. Journal of Infectious Diseases 1945; 76:55-69.
  • 😷 The risk group for Belgium has been imported on 2024-02-05. The full classification is: risk group = 2, note = "MoPn: 1 animal pathogen - biological class of risk animal: 2; default: 2 human pathogen". — The risk group for Canada has been imported on 2024-02-27. The full classification is: risk group = 2, note = "lymphogranuloma venereum type 2 strain 434: 2 Animal classification RG: 2 - Security sensitive biological agent: No - Terrestrial animal pathogen under Canadian Food Inspection Agency authority: No - Containment level: Containment Level 2; default: 2 Animal classification RG: 2 - Security sensitive biological agent: No - Terrestrial animal pathogen under Canadian Food Inspection Agency authority: No - Containment level: Containment Level 2; MoPn: 2 Animal classification RG: 2 - Security sensitive biological agent: No - Terrestrial animal pathogen under Canadian Food Inspection Agency authority: No - Containment level: Containment Level 2; murine strain NIIG2: 2 Animal classification RG: 2 - Security sensitive biological agent: No - Terrestrial animal pathogen under Canadian Food Inspection Agency authority: No - Containment level: Containment Level 2". — The risk group for Swiss Confederation has been imported on 2024-02-01. The full classification is: risk group = 2. — The risk group for Germany has been imported on 2026-08-13. The full classification is: risk group = 2, note = "sr". — The risk group for France has been imported on 2024-08-30. The full classification is: risk group = 2. — The risk group for Sweden has been imported on 2024-02-05. The full classification is: risk group = 2. — The risk group for Taiwan has been imported on 2024-11-03. The full classification is: risk group = 2, note = "P650 = v". — The risk group for United States has been imported on 2024-02-09. The full classification is: risk group = 2. — If in doubt, use the risk group given in the regulations for your country and, if these are not available, use the risk group given in the catalogue of the culture collection from which you have obtained or intend to obtain the strain.
  • 🎓 Name mentioned 9999 times (maxed out) in PubMed until 2026-06-11.
  • 🙆 This name is on the List of Recommended Names for bacteria of medical importance (LoRN) as the name to be applied to this species. The name is on LoRN because of the recorded risk group of the species itself.
  • 🧍 According to Bartlett et al. (2022), this species is an established human pathogen. Publication: Bartlett A, Padfield D, Lear L, Bendall R, Vos M. A comprehensive list of bacterial pathogens infecting humans. Microbiology (Reading) 2022; 168:0. 🇬🇧
  • 🧍 See also Lodhia et al. (2026). Publication: Lodhia Z, Mixao V, Isidro J, Ferreira R, Cordeiro D, Correia C, Joao I, Pereira J, Gomes JP, Borrego MJ, et al. A new core-genome MLST approach for Chlamydia trachomatis genomic surveillance and research. Nat Commun 2026; 17:0. 🇵🇹
  • 🧍 In the Approved Lists of Bacterial Names, the type strain is erroneously cited as ATCC VR 571B (without dash). — Tang J. Personal communication, 2001-05-30.

Parent taxon: Chlamydia Jones et al. 1945 (Approved Lists 1980)

Assigned by: Rake G. Family II. Chlamydiaceae Fam. Nov. In: Breed RS, Murray EGD, Smith NR (eds), Bergey's Manual of Determinative Bacteriology, seventh edition, The Williams & Wilkins Co, Baltimore, 1957, p. 957-968.

Linking: To permanently link to this page, use https://doi.org/10.83108/rn.783629Copy to clipboardLink copied to clipboard

Record number: 783629

• Previous versions:

  • Version	Date	JSON
    1	2026-03-31