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Forward Genetic Approaches in Chlamydia trachomatis
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Published on: October 23, 2013

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Chlamydia psittaci comparative genomics reveals intraspecies variations in the putative outer membrane and type III

Bernard J Wolff1, Shatavia S Morrison2, Denise Pesti3

  • 11​Infectious Diseases Laboratory, College of Veterinary Medicine, University of Georgia, Athens, GA, USA 2​Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA.

Microbiology (Reading, England)
|April 19, 2015
PubMed

Insights

Chlamydia psittaci, a bacterium causing psittacosis, shows genetic variation in key virulence factors. This variation in polymorphic outer-membrane proteins and type III secretion systems may explain differences in host infection and disease severity.

Area of Science:

  • Bacteriology
  • Genomics
  • Infectious Diseases

Background:

  • Chlamydia psittaci is an obligate intracellular bacterium responsible for psittacosis in humans and disease in various hosts.
  • Ten C. psittaci genotypes are known, distinguished by the ompA gene, with overlapping host ranges and virulence.
  • Previous research indicates frequent host switching and genomic rearrangements within the Chlamydiaceae family.

Purpose of the Study:

  • To investigate genetic variations in type III secretion system (T3SS) and polymorphic outer-membrane proteins (Pmps) among different C. psittaci genotypes.
  • To correlate observed genetic differences with host tropism and virulence potential.

Main Methods:

  • Sequencing of five C. psittaci genomes from genotypes A, B, D, and E.
  • Comparative genomic analysis of T3SS and Pmp genes across eleven C. psittaci genotypes (five newly sequenced and six previously sequenced).

Main Results:

  • Significant genetic variability was identified in Pmp and T3SS genes across the analyzed C. psittaci strains.
  • These variations may contribute to the observed differences in host specificity and disease presentation.

Conclusions:

  • Genetic diversity in T3SS and Pmp genes is a key factor influencing C. psittaci's host range and pathogenicity.
  • Further research into these genetic elements can enhance understanding and management of psittacosis.

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