Tenacibaculum piscium sp. nov., isolated from skin ulcers of sea-farmed fish, and description of Tenacibaculum finnmarkense sp. nov. with subdivision into genomovars finnmarkense and ulcerans

Int J Syst Evol Microbiol. 2020 Dec;70(12):6079-6090. doi: 10.1099/ijsem.0.004501.

Abstract

Results of previous multilocus sequence and whole-genome-based analyses have suggested that a homogeneous group of isolates belonging to the genus Tenacibaculum, represented by strain TNO020T and associated with skin ulcer development in sea-farmed fish, represents an as-yet-undescribed species. Comparative whole-genome analysis performed in the present study clustered five isolates, including TNO020T, in a distinct lineage within the genus Tenacibaculum. Phenotypic differences, high intra-cluster average nucleotide identity (ANI) values and low ANI values with other Tenacibaculum species support the proposal of a novel species, for which we propose the name Tenacibaculum piscium sp. nov. with strain TNO020T (=CCUG 73833T=NCIMB 15240T) as the type strain. Further, large-scale genome analyses confirmed the existence of two different phylogenetic lineages within 'T. finnmarkense', a species effectively but not validly published previously. ANI values just above the species delineation threshold of 95-96 % confirmed that both lineages belong to the same species. This result was also supported by DNA-DNA hybridization values. Phenotypically, the two conspecific lineages are distinguishable by differences in growth temperature range and ability to degrade l-proline. For the group of isolates already commonly known as 'T. finnmarkense', we propose the name Tenacibaculum finnmarkense sp. nov., with strain TNO006T (=CCUG 73831T=NCIMB 15238T) as the type strain. We further propose the subdivision of T. finnmarkense sp. nov. into two genomovars, T. finnmarkense genomovar finnmarkense with strain TNO006T (=CCUG 73831T=NCIMB 15238T) as the type strain and T. finnmarkense genomovar ulcerans with strain TNO010T (=CCUG 73832T=NCIMB 15239T) as the type strain.

Keywords: Tenacibaculum finnmarkense; Tenacibaculum finnmarkense genomovar finnmarkense; Tenacibaculum finnmarkense genomovar ulcerans; Tenacibaculum piscium; cgMLST; tenacibaculosis.

MeSH terms

  • Animals
  • Bacterial Typing Techniques
  • Base Composition
  • DNA, Bacterial / genetics
  • Fatty Acids / chemistry
  • Fish Diseases / microbiology*
  • Fishes / microbiology*
  • Norway
  • Nucleic Acid Hybridization
  • Phylogeny*
  • RNA, Ribosomal, 16S / genetics
  • Sequence Analysis, DNA
  • Skin Ulcer / microbiology*
  • Tenacibaculum / classification*
  • Tenacibaculum / isolation & purification
  • Whole Genome Sequencing

Substances

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

Supplementary concepts

  • Tenacibaculum finnmarkense