Species Clostridium difficile

Name: Clostridium difficile (Hall and O'Toole 1935) Prévot 1938 (Approved Lists 1980)

Category: Species

Proposed as: comb. nov.

Basonym: "Bacillus difficilis" Hall and O'Toole 1935

Etymology: dif.fi’ci.le. L. neut. adj. difficile, difficult (referring to “the unusual difficulty that was encountered in its isolation and study”)

Pronunciation (Latin), gender: klos-TRI-di-um dif-FI-ki-le, neuter

Type strain: ATCC 9689; BCRC 10642; CCRC 10642; CCUG 4938; CGMCC 1.2184; CIP 104282; DSM 1296; JCM 1296; LMG 15861; NCIB 10666; NCIMB 10666; NCTC 11209

Conduct genome-based taxonomy at

16S rRNA gene: AB548672 Analyse FASTA

Effective publication: Prévot AR. Études de systématique bactérienne. IV. Critique de la conception actuelle du genre Clostridium. Annales de l'Institut Pasteur (Paris) 1938; 61:72-91.

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

Taxonomic status: synonym (and not recommended for medical use)

Correct name: Clostridioides difficile (Hall and O'Toole 1935) Lawson et al. 2016

Risk group: 2

Synonyms:

Name	Kind
Clostridioides difficile (Hall and O'Toole 1935) Lawson et al. 2016	homotypic synonym, validly published under the ICNP
"Peptoclostridium difficile" (Hall and O'Toole 1935) Yutin and Galperin 2013	homotypic synonym, not validly published
"Bacillus difficilis" Hall and O'Toole 1935	homotypic synonym, not validly published, basonym of name in Approved Lists

Notes:
- ❗ Clostridium difficile is the correct name instead if this species is regarded as a separate species (i.e., if its nomenclatural type is not assigned to another species whose name is validly published, legitimate and not rejected and has priority) within a separate genus Clostridium.
- 😷 The risk group for Belgium has been imported on 2024-02-05. The full classification is: risk group = 2, note = "human and animal pathogen - human: T - biological class of risk animal: 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 2023-10-29. The full classification is: risk group = 2. — The risk group for France has been imported on 2024-08-30. The full classification is: risk group = 2, note = "T". — 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 Kingdom has been imported on 2024-01-31. The full classification is: risk group = 2, note = "Toxigenic". — 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 a synonym of the name to be applied to this species. The name is on LoRN because of the recorded risk group of the species itself.
- 🧍 See Oren and Rupnik (2018) for details on the nomenclature of this species. Publication: Oren A, Rupnik M. Clostridium difficile and Clostridioides difficile: Two validly published and correct names. Anaerobe 2018; 52:125-126. 🇮🇱

Parent taxon: Clostridium Prazmowski 1880 (Approved Lists 1980)

Assigned by: Prévot AR. Études de systématique bactérienne. IV. Critique de la conception actuelle du genre Clostridium. Annales de l'Institut Pasteur (Paris) 1938; 61:72-91.

Linking: To permanently link to this page, use https://doi.org/10.83108/rn.774867Link copied to clipboard

Record number: 774867

This LPSN page was printed on 2026-08-12 17:11:05

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Species Clostridium difficile