VII.Fungal Diseases

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VII. Fungal Diseases

• A. Basic Properties of the Fungi
• B. Candidiasis
• C. Dermatomycoses
• D. Respiratory Fungal Infections

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VII. A. Basic Properties of the Fungi

• Cellular Structure
• Eukaryotic Cells
• Fungal Cell Wall Structure
• Chitin
• Cellulose
• Heterotrophic Metabolism
• Decomposers
• Some parasitic species

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VII. A. Basic Properties of the Fungi

• Cell Arrangement
• Molds Fleshy Fungi
• Hyphae
• Septate nonseptate hyphae
• Mycelium
• Yeasts
• Dimorphic fungi

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VII. A. Basic Properties of the Fungi

• Classification of the Fungi
• By Reproductive Structures
• Oomycetes
• Water Molds
• Motile sexual spores
• Example Potato blight Phytophthora

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VII. A. Basic Properties of the Fungi

• Classification of the Fungi (cont.)
• Zygomycetes
• Unenclosed zygospores produced at ends of hyphae
• Example Black bread mold Rhizopus
• Ascomycetes
• Ascospores are enclosed in asci (sac-like
  structures) at the ends of hyphae or yeasts
• Examples Penicillium, Saccharomyces

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VII. A. Basic Properties of the Fungi

• Classification of the Fungi (cont.)
• Basidiomycetes
• Basidiospores are produced on a club-shaped
  structure called a basidium
• Example Mushrooms, Cryptococcus
• Deuteromycetes
• Imperfect fungi
• No sexual stage is known for these fungi
• Many parasitic fungi fall into this class
• Examples Candida, Epidermophyton

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VII. B. Candidiasis

• Cause Candida albicans
• Dimorphic fungus of the class Deuteromycetes
• Grows as yeast or pseudohyphae
• Spread by contact often part of normal flora
• Opportunistic infections common
• Vulvovaginitis
• Oral candidiasis (thrush)
• Intestinal candidiasis

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VII. C. Dermatomycoses

• Cause Several genera of dermatophytic fungi
• Trichophyton, an ascomycete
• Microsporum, an ascomycete
• Epidermophyton, a deuteromycete
• Grow on skin, hair, nails
• Transmitted by contact with infected persons or
  animals

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VII. C. Dermatomycoses

• Tinea infections Red, scaly or blister-like
  lesions often a raised red ring ringworm

• Tinea pedis
• Tinea corporis
• Tinea capitis
• Tinea favosa
• Tinea barbae
• Tinea cruris
• Tinea unguium

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VII. D. Respiratory Fungal Infections

• Cryptococcosis
• Cryptococcus neoformans
• A yeast of class Basidiomycetes
• Soil esp. contaminated with bird droppings
• Airborne to humans
• Gelatinous capsules resist phagocytosis
• Respiratory tract infections
• Occasional systemic infections involving brain
  meninges

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VII. D. Respiratory Fungal Infections

• Histoplasmosis
• Histoplasma capsulatum, an ascomycete
• Airborne infection
• Transmitted by inhalation of spores in
  contaminated spores
• Associated with chicken bat droppings
• Respiratory tract symptoms fever, headache,
  cough, chest pains

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VII. D. Respiratory Fungal Infections

• Blastomycosis
• Blastomyces dermatitidis, an ascomycete
• Associated with dusty soil bird droppings
• Skin transmission via cuts abrasions
• Raised, wart-like lesions
• Airborne transmission via inhalation of spores
• Respiratory tract symptoms
• Occasional internal infections with high fatality
  rate