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Cultivation Methods of Spirochetes from Borrelia burgdorferi Sensu Lato Complex and Relapsing Fever Borrelia
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Cultivation Methods of Spirochetes from Borrelia burgdorferi Sensu Lato Complex and Relapsing Fever Borrelia

Published on: November 25, 2022

Erythrocyte-aggregating relapsing fever spirochete Borrelia crocidurae induces formation of microemboli

A Shamaei-Tousi1, P Martin, A Bergh

  • 1Department of Microbiology, Umeâ University, Umeâ, Sweden.

The Journal of Infectious Diseases
|November 24, 1999
PubMed

Insights

African relapsing fever spirochete Borrelia crocidurae rapidly invades hosts, forming erythrocyte aggregates and causing tissue damage. Extravascular spread offers a novel bacterial propagation route, potentially explaining human relapsing fever symptoms.

Area of Science:

  • Microbiology
  • Immunology
  • Pathology

Background:

  • Borrelia crocidurae, the African relapsing fever spirochete, is known to aggregate with erythrocytes.
  • This aggregation is associated with a delayed immune response in the host.

Purpose of the Study:

  • To investigate the pathogenic mechanisms and host-pathogen interactions of Borrelia crocidurae infection in a murine model.
  • To elucidate the timeline of spirochetal invasion, dissemination, and resulting pathology.

Main Methods:

  • Infection of mice with Borrelia crocidurae.
  • Monitoring of infected mice over 50 days post-infection.
  • Histopathological examination of tissues (lungs, kidneys, brain) and blood vessels.

Main Results:

  • Spirochetes were observed extravascularly as early as day 2 post-infection.
  • Inflammatory responses, cell death, and tissue damage were evident by day 4.
  • Pathology in lungs and kidneys was similar; brain involvement showed delayed and less pronounced inflammation.
  • Microemboli were observed in blood vessels, linked to erythrocyte aggregation.
  • Borrelia crocidurae invasion was more rapid than observed for Lyme disease Borrelia species.

Conclusions:

  • Borrelia crocidurae exhibits rapid invasion and extravascular dissemination, representing a novel pathogenic route.
  • Erythrocyte aggregation and extravascular spread contribute to spirochetal propagation and host damage.
  • The observed histopathological findings provide insights into the clinical manifestations of human relapsing fever.

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