Ruthenibacterium

Ruthenibacterium is a genus of Gram-negative, obligately anaerobic, non-spore-forming bacteria within the family Oscillospiraceae. The genus was first described in 2016 with the identification of its type species, Ruthenibacterium lactatiformans, isolated from human feces.^[1]

Ruthenibacterium
Scientific classification
Domain:	Bacteria
Phylum:	Bacillota
Class:	Clostridia
Order:	Eubacteriales
Family:	Oscillospiraceae
Genus:	Ruthenibacterium Shkoporov et al., 2016
Species:	R. lactatiformans
Binomial name
Ruthenibacterium lactatiformans Shkoporov et al., 2016
Type strain
DSM 100348, VKM B-2901, 585-1T

Taxonomy

The genus Ruthenibacterium was established by Shkoporov et al. in 2016 following the isolation and characterization of two novel strains (585-1^T and 668) from the feces of healthy human subjects. Phylogenetic analysis based on 16S rRNA gene sequences indicated that these strains formed a distinct lineage within the family Oscillospiraceae, with less than 92% sequence similarity to their closest relatives, including Anaerofilum pentosovorans and Gemmiger formicilis.^[1]

Species

Currently, the genus comprises a single validly published species:

• Ruthenibacterium lactatiformans

Morphology and physiology

Ruthenibacterium lactatiformans is characterized as:

• Gram-negative in staining (despite phylogenetic placement among Gram-positive phyla)
• Rod-shaped and non-motile
• Non-spore-forming
• Strictly anaerobic

Ecology and clinical significance

Ruthenibacterium lactatiformans was originally isolated from the feces of healthy adult humans and is considered a commensal member of the gut microbiota. In 2024, the bacterium was identified in the first documented case of human infection. An elderly man with diabetes and renal failure developed vertebral osteomyelitis, and blood cultures later revealed the presence of R. lactatiformans using 16S rRNA gene sequencing.^[2]

Type strain

The type strain is 585-1^T, also known as:

• DSM 100348^T
• VKM B-2901^T