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Forward Genetic Approaches in Chlamydia trachomatis
09:03

Forward Genetic Approaches in Chlamydia trachomatis

Published on: October 23, 2013

Polymorphic membrane protein H has evolved in parallel with the three disease-causing groups of Chlamydia trachomatis

Diane R Stothard1, Gregory A Toth, Byron E Batteiger

  • 1The Department of Medicine, Division of Infectious Diseases, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA. dstothar@iupui.edu

Infection and Immunity
|February 22, 2003
PubMed

Insights

Polymorphic membrane protein (pmp) genes in Chlamydia trachomatis show sequence diversity useful for epidemiology. PmpH and PmpE gene variations correlate with ocular, urogenital, and LGV disease groups.

Area of Science:

  • Microbiology
  • Genetics
  • Epidemiology

Background:

  • Chlamydia trachomatis is a significant human pathogen responsible for trachoma, urogenital infections, and lymphogranuloma venereum (LGV).
  • Nine polymorphic membrane protein (pmp) genes, encoding putative outer membrane proteins, have been identified in C. trachomatis.
  • Sequence variability within pmp genes is hypothesized to be valuable for epidemiological studies.

Purpose of the Study:

  • To assess the sequence diversity within individual pmp genes among different serovars of C. trachomatis.
  • To identify specific pmp genes that exhibit significant sequence variation relevant for epidemiological investigations.
  • To explore the potential of pmp gene variability in differentiating C. trachomatis strains associated with distinct clinical manifestations.

Main Methods:

  • Restriction fragment length polymorphism (RFLP) analysis was employed as an initial screening method to evaluate sequence divergence across pmp genes (pmpA-pmpI) in 15 C. trachomatis serovars (A-L3).
  • Genes exhibiting substantial variation (pmpE, pmpH, pmpI) were selected for subsequent sequencing.
  • Evolutionary analysis was performed on the sequenced pmp genes to understand divergence patterns.

Main Results:

  • RFLP analysis revealed varying degrees of sequence divergence among pmp genes, with pmpA showing minimal variation and pmpI demonstrating substantial variation.
  • pmpH and pmpE RFLP patterns successfully clustered the 15 serovars into ocular, urogenital, and LGV disease groups.
  • Sequence analysis indicated that PmpI was the least variable, PmpE showed high diversity in ocular strains, and PmpH evolution reflected distinct disease groups.

Conclusions:

  • The polymorphic membrane protein (pmp) genes of Chlamydia trachomatis exhibit sequence variability that can be utilized for epidemiological studies.
  • The PmpH protein, in particular, demonstrates evolutionary patterns that align with disease groups, suggesting a potential role in pathogenesis.
  • The findings support the use of specific pmp genes, such as pmpE and pmpH, for differentiating C. trachomatis strains and understanding their clinical associations.

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