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Plasmid-mediated transformation tropism of chlamydial biovars

Lihua Song1, John H Carlson, Bing Zhou

  • 1Laboratory of Intracellular Parasites, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA; State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, China.

Pathogens and Disease
|November 12, 2013
PubMed

Insights

Chlamydia trachomatis and Chlamydia muridarum plasmids are crucial for transformation and virulence. This study reveals the plasmid

Area of Science:

  • Microbiology
  • Bacterial Genetics
  • Molecular Biology

Background:

  • Chlamydia trachomatis and Chlamydia muridarum are important pathogens.
  • Both species share a conserved 7.5-kb plasmid, a key virulence factor.
  • Transformation systems exist for C. trachomatis L2 but not for C. trachomatis serovar A or C. muridarum.

Purpose of the Study:

  • To investigate genetic transformation in Chlamydia trachomatis serovar A and Chlamydia muridarum.
  • To characterize the role of the chlamydial plasmid in transformation tropism and virulence gene regulation.

Main Methods:

  • Genetic experiments were conducted using Chlamydia trachomatis serovar A and Chlamydia muridarum.
  • Shuttle vectors with species-specific plasmid backbones were used for transformation.
  • Plasmid-deficient C. muridarum was transformed to assess complementation of glycogen accumulation and inclusion morphology.

Main Results:

  • Successful transformation of C. muridarum and C. trachomatis serovar A required species-specific plasmid backbones.
  • Transformation with a C. muridarum-based shuttle vector restored glycogen accumulation and normal inclusion morphology in plasmid-deficient C. muridarum.
  • The C. muridarum plasmid-encoded Pgp4 protein regulates chromosomal (glgA) and plasmid (pgp3) virulence genes.

Conclusions:

  • Chlamydial plasmid plays a previously unrecognized role in transformation tropism.
  • The chlamydial plasmid is confirmed to regulate virulence genes in Chlamydia muridarum.
  • These findings advance our understanding of Chlamydia genetics and virulence mechanisms.
Keywords:
Chlamydiaeplasmidtransformationtropism

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