Ureaplasma diversum Genome Provides New Insights about the Interaction of the Surface Molecules of This Bacterium with the Host

PLoS One. 2016 Sep 7;11(9):e0161926. doi: 10.1371/journal.pone.0161926. eCollection 2016.

Abstract

Whole genome sequencing and analyses of Ureaplasma diversum ATCC 49782 was undertaken as a step towards understanding U. diversum biology and pathogenicity. The complete genome showed 973,501 bp in a single circular chromosome, with 28.2% of G+C content. A total of 782 coding DNA sequences (CDSs), and 6 rRNA and 32 tRNA genes were predicted and annotated. The metabolic pathways are identical to other human ureaplasmas, including the production of ATP via hydrolysis of the urea. Genes related to pathogenicity, such as urease, phospholipase, hemolysin, and a Mycoplasma Ig binding protein (MIB)-Mycoplasma Ig protease (MIP) system were identified. More interestingly, a large number of genes (n = 40) encoding surface molecules were annotated in the genome (lipoproteins, multiple-banded antigen like protein, membrane nuclease lipoprotein and variable surface antigens lipoprotein). In addition, a gene encoding glycosyltransferase was also found. This enzyme has been associated with the production of capsule in mycoplasmas and ureaplasma. We then sought to detect the presence of a capsule in this organism. A polysaccharide capsule from 11 to 17 nm of U. diversum was observed trough electron microscopy and using specific dyes. This structure contained arabinose, xylose, mannose, galactose and glucose. In order to understand the inflammatory response against these surface molecules, we evaluated the response of murine macrophages J774 against viable and non-viable U. diversum. As with viable bacteria, non-viable bacteria were capable of promoting a significant inflammatory response by activation of Toll like receptor 2 (TLR2), indicating that surface molecules are important for the activation of inflammatory response. Furthermore, a cascade of genes related to the inflammasome pathway of macrophages was also up-regulated during infection with viable organisms when compared to non-infected cells. In conclusion, U. diversum has a typical ureaplasma genome and metabolism, and its surface molecules, including the identified capsular material, represent major components of the organism immunopathogenesis.

MeSH terms

  • Base Composition / genetics
  • Genome, Bacterial / genetics*
  • High-Throughput Nucleotide Sequencing
  • Host-Pathogen Interactions / genetics*
  • Humans
  • Inflammasomes / genetics
  • Lipoproteins / genetics
  • Metabolic Networks and Pathways / genetics
  • Molecular Sequence Annotation
  • Mycoplasma / genetics
  • Mycoplasma / pathogenicity
  • Phospholipases / genetics
  • Toll-Like Receptors / genetics
  • Ureaplasma / genetics*
  • Ureaplasma / pathogenicity
  • Ureaplasma Infections / genetics*
  • Ureaplasma Infections / microbiology
  • Ureaplasma Infections / pathology
  • Urease / genetics

Substances

  • Inflammasomes
  • Lipoproteins
  • Toll-Like Receptors
  • Phospholipases
  • Urease

Grant support

This study was supported by FAPESB (N°APP0097/2009) (Lucas Miranda Marques), FAPESP (2012/00719-2) (Jorge Timenetsky) and PROPI/UFBA (01/2013) (Lucas Miranda Marques). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.