[Biology and pathogenicity of fungi].
Men live with a multitude of fungal species and few species can become parasites. Some species are obligatory pathogenic (dermatophytes, dimorphic fungi...) and the majority is opportunistic pathogen. Host-parasite complex is indissociable. For example, Candida albicans is a commensal of the gastrointestinal tract and can dramatically proliferate when host defences are alterated. Passage from the commensal status to pathogenicity is accompanied by modifications of the fungus, which then act as virulence factors (development of filamentous forms, changes in surface hydrophobicity...). Biologic, genetic and antigenic modifications are also observed. Colonisation and adhesion, penetration, multiplication and survival are necessary for infectiosity in a host. Host defence mechanisms are described with non-specific mechanisms by humoral and cellular factors and more specific immune mechanisms involving antibodies, T lymphocytes and the role of cytokines.
Datry
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Service de parasitologie-mycologie Groupe hospitalier La Pitié-La Salpêtrière 75651 Paris.
Thellier
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D000328:Adult; D000367:Age Factors; D000368:Aged; D005260:Female; D005658:Fungi / Q000254:growth & development / Q000472:pathogenicity* / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D009181:Mycoses / Q000209:etiology / Q000276:immunology; D011247:Pregnancy; D012307:Risk Factors