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Characterization of adenylate cyclase-hemolysin gene duplication in a Bordetella pertussis isolate

Karine Dalet1, Christian Weber, Laurent Guillemot

  • 1Unité Prévention et Thérapie Moléculaires des Maladies Humaines, Institut Pasteur, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France.

Infection and Immunity
|July 24, 2004
PubMed

Insights

This study identified two Bordetella pertussis clones with differing copies of the cya gene, responsible for whooping cough toxin production. Despite genetic variations, both clones showed similar behavior in disease models, likely due to gene instability.

Area of Science:

  • Microbiology
  • Bacterial genetics
  • Toxinology

Background:

  • Bordetella pertussis causes whooping cough.
  • The adenylate cyclase-hemolysin (cya) toxin plays a role in pertussis pathogenesis.
  • Genetic variability in bacterial pathogens can influence disease presentation.

Purpose of the Study:

  • To characterize a clinical isolate of Bordetella pertussis.
  • To investigate the genetic makeup of the cya locus in different bacterial clones.
  • To assess the functional impact of cya locus duplication on virulence.

Main Methods:

  • Isolation and characterization of Bordetella pertussis clinical samples.
  • Genomic analysis to identify cya locus copy number variations.
  • In vitro cellular assays and in vivo murine models to evaluate bacterial virulence.

Main Results:

  • A clinical Bordetella pertussis isolate comprised at least two distinct clones.
  • These clones harbored either one or two copies of the cya locus.
  • No significant differences in virulence were observed between the clones in murine and cellular models.

Conclusions:

  • The cya locus duplication in Bordetella pertussis appears unstable.
  • High instability of the cya locus may mask functional differences between clones.
  • Further research is needed to understand the evolutionary dynamics of the cya locus in Bordetella pertussis.

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