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

VII. A.Basic Properties of the Fungi Cellular Structure –Eukaryotic Cells –Fungal Cell Wall Structure Chitin Cellulose –Heterotrophic Metabolism Decomposers Some parasitic species

VII. A.Basic Properties of the Fungi Cell Arrangement –Molds & Fleshy Fungi Hyphae Septate & nonseptate hyphae Mycelium –Yeasts –Dimorphic fungi

VII. A.Basic Properties of the Fungi Classification of the Fungi –By Reproductive Structures –Oomycetes Water Molds Motile sexual spores Example: Potato blight Phytophthora

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

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

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

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

VII. C.Dermatomycoses –Tinea pedis –Tinea corporis –Tinea capitis –Tinea favosa –Tinea barbae –Tinea cruris –Tinea unguium Tinea infections: Red, scaly or blister-like lesions; often a raised red ring; “ringworm”

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

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

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