Phylogenetic clustering of 4 prevalent virulence genes in Orientia tsutsugamushi isolates from human patients

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Heuristic Mining of Hierarchical Genotypes and Accessory Genome Loci in Bacterial Populations
08:03

Heuristic Mining of Hierarchical Genotypes and Accessory Genome Loci in Bacterial Populations

Published on: December 7, 2021

Hyuk Chu1, Sang-Hee Park, Eun-Ju Kim

  • 1Division of Zoonoses, Center for Immunology and Pathology, National Institute of Health, Seoul, Republic of Korea.

Journal of Microbiology (Seoul, Korea)
|March 12, 2010
PubMed

Insights

Orientia tsutsugamushi virulence genes and serotypes influence pathogenicity. This study reveals distinct fatality rates among strains, correlating with genetic variations in virulence genes and 56 kDa proteins.

Area of Science:

  • Microbiology
  • Pathogen genomics
  • Molecular epidemiology

Background:

  • Pathogenicity of microbes is linked to virulence genes.
  • The specific relationships between virulence genes and strains in Orientia tsutsugamushi remain unclear.

Purpose of the Study:

  • To classify Orientia tsutsugamushi isolates using phylogenetic analysis of virulence genes.
  • To compare fatality rates of different O. tsutsugamushi isolates in a mouse model.
  • To correlate phylogenetic data with serotype and virulence gene variations.

Main Methods:

  • Phylogenetic analysis of virulence genes.
  • Infection experiments in BALB/c mice.
  • Comparison of 56 kDa protein sequences and virulence gene clustering.

Main Results:

  • Remarkably different fatality rates were observed between O. tsutsugamushi strains Deajeon03-01 and Muju03-01.
  • Phylogenetic clustering varied when based on virulence genes versus 56 kDa protein sequences.
  • Variations were identified in specific virulence genes: dnaA, virB8, tolR, and trxA.

Conclusions:

  • Fatality rates in O. tsutsugamushi are correlated with differences in both serotypes and virulence genes.
  • Genetic variations within virulence genes contribute to differential pathogenicity.

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