enterocloster clostridioformis enterocloster clostridioformis enterocloster clostridioformis, formerly known as clostridium clostridioforme, is an anaerobic, motile, gram-positive bacterium. enterocloster clostridioformis scientific classification domain: bacteria phylum: bacillota class: clostridia order: eubacteriales family: lachnospiraceae genus: enterocloster species: e. clostridioformis binomial name enterocloster clostridioformis(burri and ankersmit 1906) haas and blanchard 2020 synonyms bacterium colstridiiforme bacteroides clostridiiformis clostridium clostridioforme (burri and ankersmit 1906) kaneuchi et al. 1976 clostridium clostridiiforme description e. clostridioformis are rod-shaped bacteria which cannot grow in the presence of oxygen. while clostridium species have cell walls that resemble gram-positive bacteria, e. clostridioformis often appears negative by gram stain. history the organism now classified as e. clostridioformis was first identified in the 1950s in human and animal feces and assigned to the genus of gram-negative non-spore-forming bacteria bacteroides. in subsequent years, these bacteria were shown to form spores, causing them to be reclassified in the genus clostridium. most recently this species has been reclassified as e. clostridioformis based on phylogeny.