Allocoprobacillus halotolerans gen. nov., sp. nov and Coprobacter tertius sp. nov., isolated from human gut microbiota

Int J Syst Evol Microbiol. 2023 Jul;73(7). doi: 10.1099/ijsem.0.005950.

Abstract

Two novel bacterial isolates were cultured from faecal samples of patients attending the Breast Care clinic at the Norwich and Norfolk University Hospital. Strain LH1062T was isolated from a 58-year-old female diagnosed with invasive adenocarcinoma with ductal carcinoma in situ. Strain LH1063T was isolated from a healthy 51-year-old female. Isolate LH1062T was predicted to be a potential novel genus most closely related to Coprobacillus, whilst LH1063T was predicted to be a novel species belonging to Coprobacter. Both strains were characterized by polyphasic approaches including 16S rRNA gene analysis, core-genome analysis, average nucleotide identity (ANI) comparisons and phenotypic analysis. Initial screening of the 16S rRNA gene of LH1062T returned a nucleotide identity of 93.4 % to Longibaculum muris. For LH1063T, nucleotide identity was a 92.6 % to Coprobacter secundus. Further investigations showed that LH1062T had a genome size of 2.9 Mb and G+C content of 31.3 mol %. LH1063T had a genome size of 3.3Mb and G+C content of 39.2 mol %. Digital DNA-DNA hybridization (dDDH) and ANI values of LH1062T with its closest relative, Coprobacillus cateniformis JCM 10604T, were 20.9 and 79.54 %, respectively. For LH1063T, the dDDH and ANI values with its closest relative, Coprobacter secundus 177T, were 19.3 and 77.81 %, respectively. Phenotypic testing confirmed that LH1062T could not be matched to a known validly published isolate in any database; thereby indicating a novel genus for which the name Allocoprobacillus gen. nov. is now proposed with LH1062T (=DSM 114537T=NCTC 14686T) being the type strain of the proposed novel species Allocoprobacillus halotolerans sp. nov. Strain LH1063T (=DSM 114538T=NCTC 14698T) fits within the genus Coprobacter and, it being the third species within this genus, the name Coprobacter tertius sp. nov. is proposed.

Keywords: faecal culturing; human gut microbiota.

Publication types

  • Case Reports

MeSH terms

  • Bacterial Typing Techniques
  • Bacteroidetes
  • Base Composition
  • Clostridiaceae / genetics
  • DNA, Bacterial / genetics
  • Fatty Acids* / chemistry
  • Gastrointestinal Microbiome*
  • Humans
  • Middle Aged
  • Nucleic Acid Hybridization
  • Phylogeny
  • RNA, Ribosomal, 16S / genetics
  • Sequence Analysis, DNA

Substances

  • Fatty Acids
  • RNA, Ribosomal, 16S
  • DNA, Bacterial

Supplementary concepts

  • Coprobacter secundus