Dialister hominis sp. nov., isolated from human faeces

Int J Syst Evol Microbiol. 2020 Jan;70(1):589-595. doi: 10.1099/ijsem.0.003797.

Abstract

An obligately anaerobic, Gram-stain-negative, rod or coccobacilli organism was isolated from a faecal sample of a healthy Japanese woman. In the 16S rRNA gene sequence analysis, strain 5BBH33T showed the highest 16S rRNA gene sequence similarity to Dialister succinatiphilus YIT 11850T (95.9 %), Dialister propionicifaciens ADV 1053.03T (94.3 %), Dialister micraerophilus DSM 19965T (93.1 %), Dialister invisus DSM 15470T (92.5 %) and Dialister pneumosintes ATCC 33048T (91.4 %). The hsp60 gene sequence analysis also revealed strain 5BBH33T had relatively low hsp60 gene sequence similarities (74.4-85.3 %) to other Dialister species. Strain 5BBH33T showed 21.8-23.9 % in silico DNA-DNA hybridization values with other Dialister species. In addition, the average nucleotide identity values between strain 5BBH33T and other Dialister species ranged from 68.7-74.2 %, indicating that this strain should be considered as new species based on whole-genome relatedness. Strain 5BBH33T was asaccharolytic and largely unreactive for commercial kit. However, its growth was enhanced by adding 1 % (w/v) succinate to the medium; strain 5BBH33T was able to decarboxylate succinate to propionate. The strain 5BBH33T genome contained the enzymes involved in succinate utilization. These results improve our understanding of succinate-utilizing bacteria. On the basis of the collected data, strain 5BBH33T represents a novel species in the genus Dialister, for which the name Dialister hominis sp. nov. is proposed. The type strain of D. hominis is 5BBH33T (=JCM 33369T=DSM 109768T).

Keywords: Dialister; hsp60; human faeces; succinate-utilizing bacteria.

MeSH terms

  • Bacterial Typing Techniques
  • Base Composition
  • DNA, Bacterial / genetics
  • Feces / microbiology*
  • Female
  • Humans
  • Japan
  • Nucleic Acid Hybridization
  • Phylogeny*
  • RNA, Ribosomal, 16S / genetics
  • Sequence Analysis, DNA
  • Veillonellaceae / classification*
  • Veillonellaceae / isolation & purification

Substances

  • DNA, Bacterial
  • RNA, Ribosomal, 16S