Taxonomy of Clostridium clusters XIVa and IV

EzBioCloud Genome Database
Bacterial identification in clinical diagnostic laboratories using 16S rRNA sequences

Taxonomy of Clostridium clusters XIVa and IV

Clostridium clusters XIVa and IV are groups of bacteria that have been known as major players in the human microbiome(Hold et al., 2002;Frank et al., 2007; Manson et al., 2008). The designation of these clusters was first proposed by Collins et al. 1994 using 16S rRNA phylogeny.

The genus Clostridium was a dumping ground for species with certain phenotypes (e.g., anaerobic endospore-forming).  Clostridium clusters XIVa and IV do not represent formal nomenclature nor do they indicate a single taxa such as genus or family. Since 1994, Many of the originally designated species belonging to Clostridium clusters XIVa and IV have been reclassified into new genera. However, there are still misclassified, thereby holding old names, Clostridium species in these clusters.

Below is the taxa, in the current EzBioCloud database, that correspond to the Clostridium clusters XIVa and IV. Please visit the EzBioCloud’s page for the genus to see how the genus distributes in different human body parts (by clicking the genus name).

Clostridium cluster XIVa

Clostridium cluster XIVa is now classified as several genera, but not all genera, in the family Lachnospiraceae.


The list of genera is given below:

  • The genus Acetitomaculum Greening and Leedle 1995
  • The genus Anaerocolumna Ueki et al. 2016
  • The genus Blautia Liu et al. 2008
  • The genus Clostridium_g11 contains
    • Clostridium aminophilum Paster et al. 1993
  • The genus Clostridium_g19 contains
    • Clostridium herbivorans Varel et al. 1995
    • Clostridium polysaccharolyticum (van Gylswyk 1981) van Gylswyk et al. 1983
  • The genus Clostridium_g24 contains
    • Clostridium aldenense Warren et al. 2007
    • Clostridium asparagiforme Mohan et al. 2007
    • Clostridium bolteae Song et al. 2003
    • Clostridium citroniae Warren et al. 2007
    • Clostridium clostridioforme (Burri and Ankersmit 1906) Kaneuchi et al. 1976
    • Clostridium lavalense Domingo et al. 2009
    • Clostridium symbiosum (Stevens 1956) Kaneuchi et al. 1976
  • The genus Clostridium_g31 contains
    • Clostridium populeti Sleat and Mah 1985
  • The genus Coprococcus_g2 contains
    • Clostridium nexile Holdeman and Moore 1974
    • Coprococcus comes Holdeman and Moore 1974
  • The genus Faecalicatena Sakamoto et al. 2017
  • The genus Hungatella Kaur et al. 2014
  • The genus Roseburia Stanton and Savage 1983
  • The genus Ruminococcus_g4 contains
    • Ruminococcus faecis Kim et al. 2011
    • Ruminococcus lactaris Moore et al. 1976
    • Ruminococcus torques Holdeman and Moore 1974
  • The genus Syntrophococcus Krumholz and Bryant 1986


Clostridium cluster IV

Clostridium cluster IV is now classified as several genera, but not all genera, in the family Ruminococcaceae.


The list of genera is given below:

Since the definition of these two clusters is not consistent in recent publications and somewhat ambiguous, it is highly recommended to avoid using these terms. There are still many Clostridium species that require re-classification. Perhaps, the genome-based method can resolve this problem in the near future.



With Hyunseok Oh

Last updated on Setp. 18, 2018