Morphology
• Eukaryotic
• Unicellular fungi (yeast)
• Multicellular fungi (hyphae)
• Hypha – mycelium (vegetative, aerial, reproductive)
• Asexual spores
o Conidium – macroconidium, microconidium
o Thallospore – blastospore, chlamydospore, arthrospore
o Sporangiospore
Culture
• Sabouraud culture media – need to add antibiotics to be selective for what you want to grow
• Potato dextrose agar
• Optimal pH 6-8
• Optimal temp 22-28C – some deep pathogenic fungi require 37C (in order to grow in human)
• Aerobic
• Will grow easily, so need to be careful when culturing bacteria don’t have any fungal contamination
• Types of colonies – yeast, filamentous
• Multiplication
o Budding
o Hypha formation
o Branching/disruption of hypha
o Spore formation
Pathogenic fungi
• Ascomycota – sexual reproduction in a sack (‘acus’) with production of ascospores (e.g.,
Aspergillus, Candida)
• Basidiomycota – sexual reproduction in a sack (‘basidium’) with production of basidiospores (e.g.,
Cryptococcus)
• Zygomycota
o Sexual reproduction by gametes
o Asexual reproduction with formation of zygospores
• Mitosporic fungi (fungi imperfecti)
o No recognisable form of sexual reproduction – don’t really produce sexually
o Includes most pathogenic fungi
Mycotic diseases
• Hypersensitivity – allergic reaction to molds/spores (inhalation)
• Mycotoxicosis – poisoning of human/animal by foods/feeds contaminated by fungi which produce
toxins from grain substrate (ingestion)
• Oncogenic – mycotoxin, tumour formation
• Mycetismus – ingestion of toxic mushroom
• Mycoses (infection)
, Superficial mycoses
• Outer layers of skin, hair and nails
• Do not invade living tissue
• Dermatophytes – 3 genera
o Trichophyton spp (19 species)
o Microsporum spp
o Epidermophyton floccosum
• Keratinophillic fungi – feed on keratinocytes (keratin); keratin is nutrient source
• Produce extracellular enzymes – keratinases hydrolyse keratin
• Tinea spp – fungal infection of the skin (ringworm)
• Tinea versicolour/ Pityriasis versicolor
o Malassezia furfur (lipophilic yeast)
o Asymptomatic, chronic, recurrent infection of stratum corneum
o Patchy discolouration – hypo- to hyperpigmentation
o Chest abdomen, upper limbs, back
o Treatment – selenium sulphide shampoo, imidazole
• White Piedra
o Soft nodules of yeast cells and arthroconidia at bottom of hair shafts
o Trichosporon beigelii
o Treatment – oral terbinafine
• Dermatophytosis
o Ringworm of the scalp, glabrous skin and nails
o Dermatophytes (Microsporum, Trichophyton, Epidermophyton)
o Treatment – azoles
• Candidiasis
o Skin, mucous membranes and nails
o Candida albicans and Candida auris
o Candida spp resistance to antifungals
• Tinea capitis
o Infection of shaft of scalp hair
o Kerion
▪ Inflammatory reaction producing raised, boggy mass on scalp
▪ Suppurating at multiple sites
o Favus
▪ Formation of crusts around infected hair follicles
▪ Arthrospore present within hair shafts
• Tinea barbae – beard and moustache infection
• Tinea gladiatorum
o Wrestlers and athletes
o Direct skin to skin contact
o Lesions on arms, trunk, head, neck (areas of greatest contact)
• Tinea cruris
o Tropical countries
o Infection of groin – mostly in men wearing tight garments
o Involves perineum, scrotum, peri-anal areas
• Tinea manuum
o Infection of hands
o Diffuse hyperkeratosis
• Tinea pedis
o Athlete’s foot
• Eukaryotic
• Unicellular fungi (yeast)
• Multicellular fungi (hyphae)
• Hypha – mycelium (vegetative, aerial, reproductive)
• Asexual spores
o Conidium – macroconidium, microconidium
o Thallospore – blastospore, chlamydospore, arthrospore
o Sporangiospore
Culture
• Sabouraud culture media – need to add antibiotics to be selective for what you want to grow
• Potato dextrose agar
• Optimal pH 6-8
• Optimal temp 22-28C – some deep pathogenic fungi require 37C (in order to grow in human)
• Aerobic
• Will grow easily, so need to be careful when culturing bacteria don’t have any fungal contamination
• Types of colonies – yeast, filamentous
• Multiplication
o Budding
o Hypha formation
o Branching/disruption of hypha
o Spore formation
Pathogenic fungi
• Ascomycota – sexual reproduction in a sack (‘acus’) with production of ascospores (e.g.,
Aspergillus, Candida)
• Basidiomycota – sexual reproduction in a sack (‘basidium’) with production of basidiospores (e.g.,
Cryptococcus)
• Zygomycota
o Sexual reproduction by gametes
o Asexual reproduction with formation of zygospores
• Mitosporic fungi (fungi imperfecti)
o No recognisable form of sexual reproduction – don’t really produce sexually
o Includes most pathogenic fungi
Mycotic diseases
• Hypersensitivity – allergic reaction to molds/spores (inhalation)
• Mycotoxicosis – poisoning of human/animal by foods/feeds contaminated by fungi which produce
toxins from grain substrate (ingestion)
• Oncogenic – mycotoxin, tumour formation
• Mycetismus – ingestion of toxic mushroom
• Mycoses (infection)
, Superficial mycoses
• Outer layers of skin, hair and nails
• Do not invade living tissue
• Dermatophytes – 3 genera
o Trichophyton spp (19 species)
o Microsporum spp
o Epidermophyton floccosum
• Keratinophillic fungi – feed on keratinocytes (keratin); keratin is nutrient source
• Produce extracellular enzymes – keratinases hydrolyse keratin
• Tinea spp – fungal infection of the skin (ringworm)
• Tinea versicolour/ Pityriasis versicolor
o Malassezia furfur (lipophilic yeast)
o Asymptomatic, chronic, recurrent infection of stratum corneum
o Patchy discolouration – hypo- to hyperpigmentation
o Chest abdomen, upper limbs, back
o Treatment – selenium sulphide shampoo, imidazole
• White Piedra
o Soft nodules of yeast cells and arthroconidia at bottom of hair shafts
o Trichosporon beigelii
o Treatment – oral terbinafine
• Dermatophytosis
o Ringworm of the scalp, glabrous skin and nails
o Dermatophytes (Microsporum, Trichophyton, Epidermophyton)
o Treatment – azoles
• Candidiasis
o Skin, mucous membranes and nails
o Candida albicans and Candida auris
o Candida spp resistance to antifungals
• Tinea capitis
o Infection of shaft of scalp hair
o Kerion
▪ Inflammatory reaction producing raised, boggy mass on scalp
▪ Suppurating at multiple sites
o Favus
▪ Formation of crusts around infected hair follicles
▪ Arthrospore present within hair shafts
• Tinea barbae – beard and moustache infection
• Tinea gladiatorum
o Wrestlers and athletes
o Direct skin to skin contact
o Lesions on arms, trunk, head, neck (areas of greatest contact)
• Tinea cruris
o Tropical countries
o Infection of groin – mostly in men wearing tight garments
o Involves perineum, scrotum, peri-anal areas
• Tinea manuum
o Infection of hands
o Diffuse hyperkeratosis
• Tinea pedis
o Athlete’s foot
