Midterm exam Reviewer Flashcards
Unicellular, reproduce by budding Forms a bacterial-like colony
Yeast
Multicellular
Woolly (Fuzzy) appearance in culture
Molds
Molds is made up of
Mycelium and hyphae
Intertwining structures
composed of hyphae
Mycelium
• Tubelike structures
• Fundamental units of fungi
Hyphae
Parts of Hyphae
Aerial (reproductive)
Vegetative (thallus)
• Above the surface
• Produce conidia / spores
Aerial (reproductive)
• Extends downward into the medium
• Absorbs water and nutrients
Vegetative (thallus)
Types of Hyphae
Septate
Sparsely septate
With frequent crosswalls
Septate
• Aseptate
• Few cross walls
Sparsely septate
Structures associated to hyphae
Conidiophore / Sporangiophore
Conidia / Sporangium
Phialide / Annellide
Vesicle / Columella
Stalks for conidia / sporangium
Conidiophore / Sporangiophore
Asexual structures that form at the hyphae or conidiophore / sporangiophore
Conidia / Sporangium
Secondary segments born from
conidio/sporangiophore
Phialide / Annellide
Enlarged or dome shaped structure at the tip of conidio / sporangiophore
Vesicle / Columella
Other hyphal forms
Spirals
Nodular bodies
Racquet
Pectinate body
Favic Chandelier
• Coiled hyphae
• E.g T. Mentagrophytes
Spirals
Knot of twisted hyphae
E.g
• M. canis
• T. mentagrophytes
Nodular bodies
Club shaped
E.g
• E. floccosum
Racquet
“Broken comb”
E.g
• M. audouinii
Pectinate body
Antler hyphae
E.g
• T. schoenleinii
• T. violaceum
Favic Chandelier
Non- or lightly pigmented
Hyaline (Moniliaceous)
Darkly pigmented (Melanin)
Dematiaceous
Ability to exist in two forms:
i. Yeast or Spherule phase at 37°C
ii. Mold phase at 25°C
Dimorphism (Dimorphic Fungi)
Have both yeast and mold forms in the same culture
Polymorphism (Polymorphic Fungi)
Growth temp of Yeast or Spherule phase
37°C
Growth phase of Mold phase
25°C
Reproduction:
Forms conidia from hyphae of 1 organism
Asexual
Reproduction:
Forms spores by merging of cell and nuclei
Sexual
Results in the formation of conidia
Asexual
Types of Conidia
Conidia
Macroconidia
Microconidia
Asexual spores that form on the
hyphae or conidiophore
Conidia
large and multicelled
Macroconidia
small and unicellular
Microconidia
Spores develop from vegetative mycelium
Blastoconidia (blastospores) Chlamydoconidia (chlamydospores) Arthroconidia (arthrospores)
Daughter cell that buds from mother cell, hyphae or pseudohyphae
Blastomyces, Histoplasma, Paracoccidioides, Sporothrix
C. albicans, G. candidum, T. beigelii C. neoformans
Blastoconidia (blastospores)
Formed from “rounding up” and enlargement of hyphal segments
• • •
Terminal (tip)
Sessile (sides)
Intercalary (within)
• P. brasiliensis, C. albicans
Chlamydoconidia (chlamydospores)
Fragmentation of the hyphae
into barrel- or rectangular- shape spores
• Coccidioides
• Geotrichum
• Trichosporon
Arthroconidia (arthrospores)
Spores contained in sacs (sporangium)
Sporangiospores
• Produced at tip of sporangiophore
• Glomerulomycetes (Zygomycetes)
Sporangiospores
Merging of cells and nuclei of two cells with Types of specialized spores
Sexual
Types of specialized spores
i. Ascospores ii. Zygospores
iii. Basidiospore iv. Oospore
contained in a saclike ascus
Molds with septate hyphae
Ascospores (Sac Fungi)
Large spore in a thick wall
Molds w/aseptate hyphae Fusion of 2 identical cells
Zygospores (Conjugation Fungi)
Spores produced on a basidium
Septate hyphae
Basidiospores (Club Fungi)
Fusion of 2 separate non identical cells
Oospore
Phases of Reproduction
i. Teleomorph
ii. Anamorph
iii. Synanamorphs
Reproduce sexually
Teleomorph
When a teleomorph produce asexually
Anamorph
If >1 anamorph is present for the same teleomorph
Synanamorphs
Aseptate
Presence of Sporangium Mucor, Rhizopus and Absidia
Zygomycota (Glomerulomycota)
Septate
Presence of Ascospores
Microsporum, Trichophyton and P. boydii
Ascomycota
Septate w/ clamp connections Presence of Basidiospores Filobasidiella neoformans
Basidiomycota
Fungi Imperfecti
No mode of sexual reproduction Largest number of species
Deuteromycota
Agents of Mycoses
- Superficial Mycoses
- Cutaneous Mycoses
- Subcutaneous Mycoses
- Systemic Mycoses
- Opportunistic Mycoses
- Yeast & Yeast-like
General Characteristics
• Affects the outermost layer (stratum corneum) of the skin or hair
Superficial Mycoses
Clinical Manifestations of Superficial Mycoses
i. Malassezia furfur
ii.Hortaea werneckii
iii. Piedraia hortae
iv. Trichosporonbeigeliicomplex
Clinical Manifestations and Lab Diagnosis of Malassezia furfur
a. Clinical Manifestations
• Tinea versicolor (pityriasis versicolor)
• Pale or fawn patches in skin
b. Laboratory Diagnosis
• Cluster of Budding yeasts w/ hyphae
• “Spaghetti and meatballs”
Clinical Manifestations and Lab Diagnosis
Hortaea werneckii
a. Clinical Manifestations
• Tinea nigra
• brown to black macules in palms & soles
b. Laboratory Diagnosis
• Dark 1-2 (budding) cell • blastoconidia
Clinical Manifestations and Lab Diagnosis
iii. Piedraia hortae
a. Clinical Manifestations
• Black Piedra
• Brown to black crusts / nodules on hair b. b. Laboratory Diagnosis
• Dark hyphae with swelling (ascus)
Clinical Manifestations and Lab Diagnosis
iv. Trichosporonbeigeliicomplex
a.Clinical Manifestations
• White piedra
• Dark hyphae with swelling (ascus)
b. Laboratory Diagnosis
• Hyaline hyphae
• Blastoconidia and arthroconidia
General Characteristics Agents of dermatophytoses
Keratinophilic
(hair, nails and skin)
Asexual reproductive cells
Cutaneous Mycoses
Infection: i. Scalp
- Tinea Favosa
- Tinea capitis
a. Gray pitch ringworm
b. Black-dot ringworm
Agent of Tinea favosa
T. schoenleinii
Agent of Tinea capitis a. Gray-patch ringworm
Microsporum spp.
Agent of Tinea capitis b. Black-dit ringworm
Trichophyton spp.
Infections: ii. Beard
Tinea barbae
Agent of Tinea barbae
Trychophyton spp.
Infections: iii. Body
Tinea corporis
Agent of Tinea corporis
Trychophyton spp.
Microsporum spp.
Infections: iv. Groin
Tinea cruris
Agent of Tinea cruris
Epidermophyton sp.
Infections: v. Feet
Tinea pedis
(Athlete’s, Moccasin)
Agent of Tinea pedis
Trychophyton spp.
Agent of Athlete’s, Moccasin)
Epidermophyton sp.
Infections: vi. Nail
Tinea unguium
(Onychomycosis)
Agent of Tinea unguium
Trychophyton spp.
Agent of Onychomycosis
Epidermophyton sp.
Dermatomycosis (Keratinized tissues):
Ringworm
Tinea capitis
Tinea corporis
Tinea unguium
Site Affected of Tinea
capitis
Head (hair)
Agent of Tinea
capitis
Microsporum
Trichophyton
Site Affected of Tinea corporis
Body (skin)
Agent of Tinea corporis
Microsporum
Trichophyton
Epidermophyton
Site affected of Tinea unguium
Nails
Agent of Tinea unguium
Trichophyton
Epidermophyton
Microconidia of E. floccosum
Absent
Macroconidia of E. floccosum
Singly or in clusters
Broad and spatulate
Contains 2-5 cells
Microconidia of M. canis
Sparse: clavate, sessile
Macroconidia of M. canis
Spindle shape, echinulate 3-15 cells, tapered ends
Microconidia of M. gypseum
Sparse: clavate, sessile
Macroconidia of M. gypseum
Cigar-shaped, with spiny surface and rounded tips
Microconidia of M. audouinii
Rare; Chlamydospores
Macroconidia of M. audouinii
Chlamydoconidia-like swellings, bizzare-shaped
Growth in Rice Grains of M. audouinii
Poor
Fluorescence in Woods Lamp of M. audouinii
Positive
Growth in Rice Grains of M. canis
Good
Fluorescence in Woods Lamp of M. canis
Positive
Growth in Rice Grains of M. gypseum
Good
Fluorescence in Woods Lamp of M. gypseum
Negative
Microconidia of T. mentagrophytes
Teardrop/globose Grapelike clusters
Macroconidia of T. mentagrophytes
Rare: Cigar-shaped; Coiled spiral hyphae
Microconidia of T. rubrum
Clavate- peg- tear- shaped: Sessile
Macroconidia of T. rubrum
Pencil-shaped Cylindrical
Microconidia of T. tonsurans
Abundant tear- club- peg- ballon- shaped
Macroconidia of T. tonsurans
Cylindrical
Species: T. mentagrophytes
Thiamine Req.
Urease
Hair Baiting
Neg
Pos (2 d)
Pos
Species: T. rubrum
Thiamine Req.
Urease
Hair Baiting
Neg
Neg (≥7 d)
Neg
Species: T. tonsurans
Thiamine Req.
Urease
Hair Baiting
Pos
Neg (4 d)
Neg
General Characteristics
• Result from traumatic puncture of thorns or vegetation contaminated with fungi
Subcutaneous Mycoses
• Verrucous dermatitidis and chromomycosis
• Caused by dematiaceous fungi
Chromoblastomycosis
Chromoblastomycosis species
Phialophora verrucosa
Cladophialophora carrionii
Fonsecaea spp.
Microscopic Morphology of Phialophora verrucosa
• Flask-shapedphialideswithcollarettes
• Conidiaoccurinballsattipsofphialides
Granulomatous infection of tissue
Mycetomas
Mycetomas Species
Pseudalleschria boydii
Pseudalleschria boydii Microscopic Morphology
• Anamorphic form of S.apiospernum
• Cleistothecia containing ascospores
Caused by dematiaceous fungi
Phaeohyphomycosis
Gardening, exposure to rose thorns (rose-handler’s disease) and sphagnum moss
Sporotrichosis
Sporotrichosis Species
Sporothrix schenckii
Sporothrix schenckii Microscopic Morphology
Small, cigar shaped yeast
• Conidia in a “rosette” or “sleeve”
pattern
General Characteristics
Dimorphic: mould (22-30°C) or yeast (35-
37°C)
Systemic Mycoses
Systemic Mycoses Species
B. dermatitidis
H. capsulatum
C. immitis
P. brasiliensis.
Ecology B. dermatitidis
River valleys and basins, soil
Disease/Manifestations B. dermatitidis
• Gilchrist • Chicago
Ecology of H. capsulatum
Bird, bat guano alkaline soil
Disease/Manifestations H. capsulatum
• Cave, Spelunker’s • Darling
Ecology C. immitis
Soil
Disease/Manifestations C. immitis
• Desert bumps, Valley fever
• Desert rheumatism
Ecology P. brasiliensis
Soil
Disease/Manifestations P. brasiliensis
South American Blastomy.
• Lutz-Splendore-Almeida.
Morphology of Blastomyces dermatitidis in Molds and Yeast
M: Ovoid conidia on short coniophores
Y: Large yeast Broad-based bud
Morphology of Coccidioides immitis in Molds and Yeast
M: Barrel-shaped arthroconidia
Y: Spherules containing endospores
Morphology of Histoplasma capsulatum in Molds and Yeast
M: Round, large, tuber- culate macroconidia
Y: Small, oval yeast
Morphology of Paracoccidioides brasiliensis in Molds and Yeast
M: Sterile hyphae Chlamydoconidia
Y: “Mariner’s wheel” “Mickey Mouse cap”
Saprophytes and Opportunistic
Opportunistic Mycoses
Aseptate Zygomycetes
Absidia
Mucor
Rhizopus
Septate Hyaline
Aspergillus
Septate Dematicaeous
Alternaria
Cladosporium
Curvularia
• Sporangium, smooth and ovoid
• Internodal Rhizoids
Absidia
• Sporangia remain intact
• Rhizoids are absent
Mucor
• Sporangiophores clusters in a stolon
• Rhizoids is at the base of
sporangiophores
Rhizopus
• Conidiophore that expands to a vesicle
• Vesicle is covered w/ phialides
Aspergillus
Unicellular, budding & round to oval organisms
Yeast & Yeastlike Fungi
Yeast & Yeastlike Fungi Species
Candida albicans
Cryptococcus neoformans
Geotrichum candidum
True Yeast
Cryptococcosis
• Pigeon, bat droppings
• Decaying vegetation
Cryptococcus neoformans
Infection of Cryptococcus neoformans
• Systemic
• meningitis
Ecology Candida albicans
GI tract
Mucus membranes
Infection Candida albicans
Thrush
Vulvovaginitis
Diaper rash
Onychomycosis
Paronychomyc
Geotrichum candidum Ecology
• Soil
• Decaying foods
Geotrichum candidum Infection
Oral, lung, skin, etc.
True Yeast
Cryptococcosis
Cryptococcus neoformans Lab Test
- Cornmeal
• Forms Round to oval yeast w/
capsule & narrow-base budding 2. Colony (Niger Seed Agar)
• Forms Brown-black colonies due to production of phenol oxidase
Candida albicans Lab Test
Direct Examination
• Blastoconidia
(budding yeast / pseudohyphae)
Cornmeal (RT, 24-48 hrs)
• Produces Chlamydoconidia
Serum (35-37oC, 1-3 hrs)
• Produces Germ Tubes
Yeast-like
Camdidiasis
Geotrichosis
Geotrichum candidum Lab Test
- Cornmeal
• Forms fragmented hyphae
(rectangular arthrospores w/ rounded ends)