Amphibian skin-associated Pigmentiphaga: Genome sequence and occurrence across geography and hosts

PLoS One. 2019 Oct 11;14(10):e0223747. doi: 10.1371/journal.pone.0223747. eCollection 2019.

Abstract

The bacterial communities colonizing amphibian skin have been intensively studied due to their interactions with pathogenic chytrid fungi that are causing drastic amphibian population declines. Bacteria of the family Alcaligenaceae, and more specifically of the genus Pigmentiphaga, have been found to be associated specifically to arboreal frogs. Here we analyze their occurrence in a previously assembled global skin microbiome dataset from 205 amphibian species. Pigmentiphaga made up about 5% of the total number of reads in this global dataset. They were mostly found in unrelated arboreal frogs from Madagascar (Mantellidae and Hyperoliidae), but also occurred at low abundances on Neotropical frogs. Based on their 16S sequences, most of the sequences belong to a clade within Pigmentiphaga not assignable to any type strains of the five described species of the genus. One isolate from Madagascar clustered with Pigmentiphaga aceris (>99% sequence similarity on 16S rRNA gene level). Here, we report the full genome sequence of this bacterium which, based on 16S sequences of >97% similarity, has previously been found on human skin, floral nectar, tree sap, stream sediment and soil. Its genome consists of a single circular chromosome with 6,165,255 bp, 5,300 predicted coding sequences, 57 tRNA genes, and three rRNA operons. In comparison with other known Pigmentiphaga genomes it encodes a higher number of genes associated with environmental information processing and cellular processes. Furthermore, it has a biosynthetic gene cluster for a nonribosomal peptide syntethase, and bacteriocin biosynthetic genes can be found, but clusters for β-lactones present in other comparative Pigmentiphaga genomes are lacking.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcaligenaceae / classification
  • Alcaligenaceae / genetics*
  • Animals
  • Anura / microbiology*
  • Biosynthetic Pathways
  • Genome Size
  • Genome, Bacterial
  • Multigene Family
  • Phylogeography
  • Plant Nectar
  • RNA, Ribosomal, 16S / genetics
  • Skin / microbiology*
  • Soil Microbiology
  • Whole Genome Sequencing / methods*

Substances

  • Plant Nectar
  • RNA, Ribosomal, 16S

Grants and funding

The sampling and culturing of amphibian skin bacteria in Madagascar was supported by a grant from the Mohamed bin Zayed Conservation Fund to MB and RH, a grant from the Amphibian Survival Alliance to MB, RH, and MV, a grant from Chester Zoo to MB and RH, a scholarship of the German Academic Exchange Service (DAAD) to MB, and a grant from the Deutsche Forschungsgemeinschaft (DFG) to MV (VE247/9-1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.