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An Ex vivo Assay to Study Candida albicans Hyphal Morphogenesis in the Gastrointestinal Tract
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An Ex vivo Assay to Study Candida albicans Hyphal Morphogenesis in the Gastrointestinal Tract

Published on: July 1, 2020

Fungal morphogenesis and virulence

G San-Blas1, L R Travassos, B C Fries

  • 1Instituto Venezolano de Investigaciones Científicas, Centro de Microbiología y Biología Celular, Caracas, Venezuela. gsanblas@pasteur.ivic.ve

Medical Mycology
|February 24, 2001
PubMed

Insights

Pathogenic fungi exhibit phenotypic variability linked to virulence, with mechanisms involving programmed changes in Cryptococcus neoformans, serine-thiol proteinase in Paracoccidioides brasiliensis, and adhesion in Candida albicans.

Area of Science:

  • Medical Mycology
  • Molecular Biology
  • Pathogenesis Research

Background:

  • Phenotypic variability in pathogenic fungi is recognized as a key factor in virulence.
  • Understanding the genetic and molecular underpinnings of this variability is crucial for disease control.
  • The XIVth Congress of the International Society for Human and Animal Mycology highlighted recent advancements in this field.

Purpose of the Study:

  • To explore the mechanisms of phenotypic variability in pathogenic fungi.
  • To correlate specific fungal traits and molecular mechanisms with disease-causing potential.
  • To present findings from experimental models of Cryptococcus neoformans, Paracoccidioides brasiliensis, and Candida albicans.

Main Methods:

  • Analysis of phenotypic traits including capsular polysaccharide, cell and colony morphology, and virulence in Cryptococcus neoformans.
  • Investigation of serine-thiol proteinase activity from the yeast phase of Paracoccidioides brasiliensis and its role in basal membrane interaction.
  • Examination of adhesion protein relationships with host immune cells (lymphocytes, neutrophils) and hyphal growth regulation in Candida albicans.

Main Results:

  • Phenotypic switching in Cryptococcus neoformans involves controlled, programmed changes, not random mutations.
  • The serine-thiol proteinase of Paracoccidioides brasiliensis cleaves basal membrane components, suggesting a role in dissemination.
  • Adhesion proteins and regulated hyphal growth in Candida albicans are linked to pathogenicity and invasive potential.

Conclusions:

  • Phenotypic variability is a regulated process in pathogenic fungi, directly impacting virulence.
  • Specific molecular mechanisms, such as proteinase activity and adhesion, are critical for fungal dissemination and pathogenicity.
  • Further research into these mechanisms can inform strategies against fungal infections in humans and animals.

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