Expression of pertussis toxin correlates with pathogenesis in Bordetella species

D Monack1, J J Munoz, M G Peacock

  • 1Department of Microbiology and Immunology, Stanford University School of Medicine, California 94305.

Insights

Pertussis toxin causes whooping cough and is key to vaccines. Introducing pertussis toxin genes into Bordetella parapertussis created active toxin, causing similar effects as in Bordetella pertussis.

Area of Science:

  • Microbiology
  • Immunology
  • Bacterial Pathogenesis

Background:

  • Pertussis toxin (PT) is a major virulence factor of Bordetella pertussis, the causative agent of whooping cough.
  • PT is also the primary component of the pertussis vaccine.
  • Bordetella parapertussis, a related species, does not naturally produce pertussis toxin.

Purpose of the Study:

  • To investigate the role of pertussis toxin in the pathogenesis of Bordetella infections.
  • To determine if toxinogenic Bordetella parapertussis strains exhibit similar toxic and reactogenic properties as Bordetella pertussis.
  • To compare the effects of expressed pertussis toxin in different Bordetella species.

Main Methods:

  • Construction of toxinogenic Bordetella parapertussis strains through conjugative transfer of cloned pertussis toxin genes.
  • Assaying toxinogenic and nontoxinogenic strains of both B. pertussis and B. parapertussis for toxicity.
  • Evaluation of reactogenic activities, including leukocytosis, anaphylaxis, and histamine sensitivity.

Main Results:

  • Expression of active pertussis toxin in Bordetella parapertussis was successfully achieved.
  • The presence of active toxin in both B. pertussis and engineered B. parapertussis correlated with specific toxic effects.
  • Leukocytosis, anaphylaxis, and histamine sensitivity were observed in strains expressing active pertussis toxin.

Conclusions:

  • Pertussis toxin is a critical determinant of virulence, inducing characteristic pathological responses.
  • The ability to confer toxin production to B. parapertussis highlights the toxin's central role in disease manifestation.
  • These findings underscore the importance of pertussis toxin in understanding whooping cough pathogenesis and vaccine efficacy.

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