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Different virulence of the species of the Pseudallescheria boydii complex

Fèlix Gilgado1, Josep Cano, Josepa Gené

  • 1Unitat de Microbiologia, Facultat de Medicina i Ciencies de la Salut, Universitat Rovira i Virgili, Reus, Spain.

Medical Mycology
|July 25, 2008
PubMed

Insights

The Pseudallescheria boydii complex includes fungi causing severe infections. Scedosporium aurantiacum and S. dehoogii showed the highest virulence in a mouse model, causing significant mortality in immunocompetent animals.

Area of Science:

  • Mycology
  • Infectious Diseases
  • Immunology

Background:

  • The Pseudallescheria boydii complex comprises several fungal species known to cause severe human infections.
  • Understanding the relative virulence of these species is crucial for clinical management and treatment strategies.

Purpose of the Study:

  • To evaluate and compare the virulence of representative species within the Pseudallescheria boydii complex using a murine model.
  • To identify which species exhibit the highest pathogenicity.

Main Methods:

  • A murine model was employed to assess fungal virulence.
  • Two distinct inocula (5 x 10(4) conidia/ml for immunosuppressed and 1 x 10(6) conidia/ml for immunocompetent mice) were administered intravenously.
  • Virulence was assessed by observing mortality rates in both immunosuppressed and immunocompetent animal groups.

Main Results:

  • Scedosporium aurantiacum and Scedosporium dehoogii demonstrated the highest virulence, leading to the death of 80% and 70% of immunocompetent mice, respectively.
  • Other species within the complex, including P. boydii sensu stricto and P. minutispora, exhibited significantly lower virulence, causing 0-20% mortality in immunocompetent mice.
  • The study assessed strains from P. boydii sensu stricto, P. minutispora, S. apiospermum, S. aurantiacum, and S. dehoogii.

Conclusions:

  • Scedosporium aurantiacum and Scedosporium dehoogii are the most virulent species within the Pseudallescheria boydii complex.
  • These findings highlight the differential pathogenicity among species in this complex, informing clinical risk assessment.
  • Further research into the mechanisms of virulence for S. aurantiacum and S. dehoogii is warranted.

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