Transcript Candida albicans

MYCOLOGY
MYCOLOGY
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The fungi are eukaryotic organisms
growing as a mass of branching,
interlacing filaments known as mycelium.
Among the many thousands of fungi known,
only about 300 can cause diseases in
humans and animals.
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Bacteria
plant
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Comparison of fungi and bacteria
feature
fungi
bacteria
diameter
4um
1um
nucleus
Eukaryotic
prokaryotic
cytoplasm
Mitochondria and
endoplasmic reticulum
present
Mitochondria and
endoplasmic reticulum
present
Cell membrane
Sterols present
Sterols absent
Cell wall
chitin
peptidoglycan
spores
Sexual and asexual spores for Endospores for survival,
reproduction
not for reproduction
Thermal
dimorphism
yes
No
metabolism
Require organic carbon; no
obligate anaerobes
May do not require
organic carbon; many
obligate anaerobes
Structure of fungi
Morphology
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Unicellular fungi
Multicellular fungi
Hypha: mycelium (vegetative, aerial or
reproductive).
Spores: asexual spore
a) Conidium（分生孢子）:
macroconidium, microconidium.
b) Thallospore（叶状孢子）:
blastospore（芽生）, chlamydospore（厚
膜）,arthrospore（关节）.
c) Sporangiospore(孢子囊孢子）
Unicellular fungi
Unicellular
fungi
Multicellular fungi
Multicellular fungi
Multicellular fungi
Hypha
•spore
Culture
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Sabouraud culture medium
optimal pH 4-6
optimal temperature 22-28 C some deep
pathogenic fungi need 37 C,
Aerobic
types of colonies– yeast, filamentous
Multiplication:budding, hypha formation,
branching or disruption of hypha, spore
formation
Resistance
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Resistant to dry, sunlight, UV light and many
chemicals
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Sensitive to wet heat
Clinical manifestations
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pathogenic fungal infection
Opportunistic pathogenic fungal infection
Fungal allergic diseases
Mycotoxicosis
Mycotoxin and tumor
Immunity
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Nonspecific immunity
Specific immunity
Microbiological
diagnosis
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Specimens
Direct smear
Isolation and cultivation
Serological tests.
Fungi of superficial
keratinized infection
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Malassezia furfur（秕糠马拉
癣菌）.
Fungi of skin infection
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The most important are dermatophytes,
a
group of closely fungi
classified into 3 genera:
Trichophyton（毛癣菌）
Epidermophyton （表皮癣菌0
Microsprum（小孢子癣菌）
Invade only skin, hair, and nails.
Fungi of subcutaneous
infection
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Chromomycosis (caused by several
species of black molds; Fonsecaea
edrosoi, Cladosporium carrionii,
Phialophora verrua have been isolated
most frequently).
Fungi of deep infection
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Cryptococcus neoformans
Histoplasma capsulatum
Coccidioides immites
( 厌酷球孢子菌〕
Blastomyes dermatitides
（皮炎芽生菌〕
Paracoccidiodes brasiliensis
（巴西副孢子菌〕
Cryptococcus neoformans
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Oval , budding yeast surrounded by a wide
polysaccharide capsule
Cryptococcus neoformans
Cryptococcus neoformans
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cryptococcosis
No human to human transmission
Infection follows inhalation of the cell of C.
neoformans, which , in nature , are thought
to be small , allowing the organism to enter
deep into the lung.
Opportunistic Mycoses
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Candida（假丝酵母菌）
Aspergillus （曲霉）
Mucor（毛霉）
Pneumocystis carinii(卡氏肺孢菌）
Candida albicans
Etiological agents
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C.albicans C.guilliermondi C.stellatoidea
C.krusei C.tropicalis
C.glabratat C.parapsilosis C.viswanathii
C.kefyr* C.lusitaniae
Clinical categories
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Cutaneous: intetrigo,paronychia,onychomycosis
Mucocutaneous: perleche, thrush, perianal disease
Chronic: mucocutaneous candidiasis, guanulomatous
disease
Systemic: fungemia ,endocarditis,pulmonary
infection,urinary tract infection, meningitis,
endophthalmitis
Yeasts
Round to oval, single cells which
reproduce by budding
Yeasts
Candida
Cryptococcus
Candidiasis
Candida albicans
Ecological Niche
Candida Albicans
Endogenous
Infections with Candida usually occur when
there is some alteration in:
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Cellular immunity
Normal Flora
Physiology
CANDIDIASIS
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Skin
Vaginitis
Urinary tract
Mucous membranes
Septicemia
Endocarditis
Pneumonia
CANDIDIASIS
The fourth most common nosocomial
bloodstream infection.
Clinical Specimens
Candida
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Sputum
Scrapings from lesions
Blood smears
Vaginal discharge
Urine
Feces
Candida albicans
8-12 MICRONS
Pseudomycelium
GERM TUBES
GEOGRAPHIC
OCCURENCE
WORLDWIDE
Therapy
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Amphotericin B
Nystatin
Ketoconazole
Fluconazole
Itraconazole
Cryptococcosis
Cryptococcus neoformans
Cryptococcosis
A sub-acute or chronic infection which
may affect the lungs or skin but most
commonly manifests as a meningitis
Ecological Niche
Cryptococcus neoformans
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pigeon droppings
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Chicken droppings
Specimen of choice
Cerebrospinal fluid
GEOGRAPHICAL
DISTRIBUTION
WORLDWIDE
Clinical Specimens
Cryptococcosis
•CSF
•Sputum
•Pus
•Biopsy material
•urine
Serological Tests
Cryptococcosis
•Indirect fluorescent antibody
•Tube Agglutination
•Latex Agglutination
(measures antigen)
Drugs of Choice
Cryptococcosis
•5-Fluorocytosine
•Amphotericin B