Medical important fungi. Biological characteristics of fungi and

laboratory diagnostics of human mycoses.

Vinnitsa National Pirogov Memorial Medical University / Department of microbiology

Fungi are divided due to their morphology into:

1. Yeasts and yeast-like fungi 2. Moulds or filamentous fungi 3. Dimorphic fungi

Morphology of yeasts and yeast-like fungi

Morphology of moulds

Taxonomy of fungiKingdom: Mycota (Fungi)Divisions: Eumycota (true fungi)

Myxomycota (mycous fungi)Classes: Fungi perfecti

1. Chytridiomycetes2. Hyphochytridiomycetes3. Oomycetes4. Zygomycetes5. Ascomycetes 6. Basidiomycetes

Fungi inperfecti : Deuteromycetes or hyphomycetes.

Cultivation of fungiNutrient media :1. Sabouraud`s glucose agar (pH 5.4)2. Sabouraud`s glucose broth3. Czapek-Dox medium4. Cornmeal agar

Cultural characteristics

Yeast-like fungi and dimorphic fungi at 370C form colonies, resemble to bacterial ones:smooth, creamy, with entire edges, colored in white, beige, and yellowish

Filamentous fungi and dimorphic fungi at 220C grow with formation fluffy, velvety colonies with any color of reverse.

Deuteromycetes usually form powdery or cottony colonies, pigmented on reverse

Morphology of mycelium elements (hyphae, spores, sporangiofores and conidiophores, macroconidia) are important identification criteria for filamentous fungi (dermatomycetes and moulds)

Colonies of filamentous fungi

Clinical classification of the fungi

1. Fungi, causing systemic or deep mycoses of humans

2. Fungi, provoking subcutaneos mycoses

3. Fungi, causing cutaneous mycoses

4. Fungi, causing opportunistic infections

Fungi, causing deep mycoses

1. Cryptococcus neoformans

2. Blastomyces dermatitidis

3. Paracoccidioides brasiliensis

4. Coccidioides immitis

5. Histoplasma capsulatum

Subcutaneous mycoses

1. Mycetoma (Madura foot, maduramycosis)2. Sporotrichosis 3. Chromoblastomycosis

Superficial mycoses1. Surface infections2. Cutaneous infections

Opportunistic systemic mycoses

Laboratory diagnostics

Fungal diseases may be diagnosed with:1. Microscopy of material from lesions2. Culture method3. Serological method 4. Allergic skin tests

Dermatomycoses

1. Trichophyton2. Microsporum3. Epidermophyton

Epidemiology

1. anthropophilic (T.rubrum, E.floccosum, M.audonii),

2. zoophilic (T.verrucosum, T.mentagrophytes, M.canis),

3. geophilic (M.gypseum, T.ajelloi).

Classification

1. Tinea corporis (T.rubrum and any other dermatophyte)

2. Tinea capitis (Microsporum any species and Trichophyton most species)

3. Tinea barbae or barber`s itch (T.rubrum, T.mentagrophytes, T.verrucosum)

4. Tinea cruris (E.flocossum, T.rubrum)5. Tinea pedis or athletes` foot disease

(T.interdigitalis, E.flocossum, T.rubrum)6. Flavus (T.schoenleinii)

Laboratory diagnostics of dermatomycoses

1. Microscopy examination2. Culture method3. Allergic skin tests with trychophytin4. Exposure to UV light

Examination of tinea capitis with Wood`s lamp

Microscopy of Microsporum species

Microscopy of Epidermophyton sp.

Microscopy of Trychophyton sp.

Candidiasis

Candidosis (candidiasis, moniliasis) is an endogenous opportunistic mycosis of the skin, mucosa and rarely of the internal organs, caused by C.albicans, C.tropicalis, C.glabrata, C.krusei and other species

Clinical forms of candidiasis

1. Cutaneous candidosis (intertriginous, paronycheal, onycheal)

2. Mucosal candidosis (oral thrush, vaginitis)

3. Intestinal candidosis

4. Bronchopulmonary candidosis

5. Systemic infections (septicemia, endocarditis and meningitis)

Oral thrush (creamy white patches on the tongue or buccal mucosa,

that leave a blooding lesions after removal)

Candidosis at AIDS patients

Cutaneous candidosis

Laboratory diagnostics of candidosis

1. Microscopy.

2. Culture method

3. Skin allergic test with candidin

4. Serological method

Scanning electron micrograph of the Candida)

Fungal diseases