MYCOLOGYMYCOLOGY
The fungi are eukaryotic organisms growiThe fungi are eukaryotic organisms growing as a mass of branching, interlacing filang as a mass of branching, interlacing filaments known as mycelium. Among the mments known as mycelium. Among the many thousands of fungi known, only abouany thousands of fungi known, only about 300 can cause diseases in humans and at 300 can cause diseases in humans and animals.nimals.
BacteriaBacteria plantplant
Comparison of fungi and Comparison of fungi and bacteriabacteria
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 reproduction
Endospores for survival, not for reproduction
Thermal dimorphism
yes No
metabolism Require organic carbon; no obligate anaerobes
May do not require organic carbon; many obligate anaerobes
MorphologyMorphology Unicellular fungiUnicellular fungi Multicellular fungiMulticellular fungi Hypha: mycelium (vegetative, aerial or reprodHypha: mycelium (vegetative, aerial or reprod
uctive).uctive). Spores: asexual sporeSpores: asexual spore a) Conidiuma) Conidium (分生孢子)(分生孢子) : : macroconidium, microconidium.macroconidium, microconidium. b) Thallosporeb) Thallospore (叶状孢子)(叶状孢子) : : blastosporeblastospore (芽生)(芽生) , chlamydospore, chlamydospore (厚(厚
膜)膜) ,arthrospore,arthrospore (关节)(关节) .. c) Sporangiospore(c) Sporangiospore( 孢子囊孢子)孢子囊孢子)
Culture Culture
Sabouraud culture mediumSabouraud culture medium optimal pH 4-6optimal pH 4-6 optimal temperature 22-28 C some deep pathogoptimal temperature 22-28 C some deep pathog
enic fungi need 37 C, enic fungi need 37 C, AerobicAerobic types of colonies– yeast, filamentoustypes of colonies– yeast, filamentous Multiplication:budding, hypha formation, branMultiplication:budding, hypha formation, bran
ching or disruption of hypha, spore formation ching or disruption of hypha, spore formation
ResistanceResistance
Resistant to dry, sunlight, UV light and many Resistant to dry, sunlight, UV light and many chemicalschemicals
Sensitive to wet heatSensitive to wet heat
Clinical manifestationsClinical manifestations
pathogenic fungal infection pathogenic fungal infection Opportunistic pathogenic fungal infectionOpportunistic pathogenic fungal infection Fungal allergic diseasesFungal allergic diseases MycotoxicosisMycotoxicosis Mycotoxin and tumorMycotoxin and tumor
Microbiological Microbiological diagnosisdiagnosis
SpecimensSpecimens Direct smearDirect smear Isolation and cultivationIsolation and cultivation Serological tests.Serological tests.
Fungi of superficial keratinized Fungi of superficial keratinized infection infection
Malassezia furfurMalassezia furfur (秕糠马(秕糠马拉癣菌)拉癣菌) ..
Fungi of skin infection Fungi of skin infection
The most important are dermatophytThe most important are dermatophytes, a group of closely fungi classified es, a group of closely fungi classified into 3 genera: into 3 genera:
TrichophytonTrichophyton (毛癣菌)(毛癣菌) Epidermophyton Epidermophyton (表皮癣菌(表皮癣菌 00 MicrosprumMicrosprum (小孢子癣菌)(小孢子癣菌) Invade only skin, hair, and nails.Invade only skin, hair, and nails.
Fungi of subcutaneous Fungi of subcutaneous infection infection
Chromomycosis (caused by several sChromomycosis (caused by several species of black molds; Fonsecaea edropecies of black molds; Fonsecaea edrosoi, Cladosporium carrionii, Phialophosoi, Cladosporium carrionii, Phialophora verrua have been isolated most frera verrua have been isolated most frequently).quently).
Fungi of deep infection Fungi of deep infection
Cryptococcus neoformans Cryptococcus neoformans Histoplasma capsulatumHistoplasma capsulatum Coccidioides immitesCoccidioides immites ( ( 厌酷球孢子菌〕厌酷球孢子菌〕 Blastomyes dermatitidesBlastomyes dermatitides (皮炎芽生菌〕(皮炎芽生菌〕 Paracoccidiodes brasiliensisParacoccidiodes brasiliensis (巴西副孢子菌〕(巴西副孢子菌〕
Cryptococcus neoformans Cryptococcus neoformans Oval , budding yeast surrounded Oval , budding yeast surrounded
by a wide polysaccharide capsuleby a wide polysaccharide capsule
Cryptococcus neoformansCryptococcus neoformans cryptococcosiscryptococcosis No human to human transmissionNo human to human transmission Infection follows inhalation of the ceInfection follows inhalation of the ce
ll of C. neoformans, which , in nature ll of C. neoformans, which , in nature , are thought to be small , allowing th, are thought to be small , allowing the organism to enter deep into the lune organism to enter deep into the lung.g.
Opportunistic MycosesOpportunistic Mycoses
CandidaCandida (假丝酵母菌)(假丝酵母菌) Aspergillus Aspergillus (曲霉)(曲霉) MucorMucor (毛霉)(毛霉) Pneumocystis carinii(Pneumocystis carinii( 卡氏肺孢菌) 卡氏肺孢菌)
Etiological agentsEtiological agents
C.albicans C.guilliermondi C.stellatC.albicans C.guilliermondi C.stellatoidea C.krusei C.tropicalis oidea C.krusei C.tropicalis
C.glabratat C.parapsilosis C.viswanC.glabratat C.parapsilosis C.viswanathii C.kefyr* C.lusitaniaeathii C.kefyr* C.lusitaniae
Clinical categoriesClinical categories
Cutaneous: intetrigo,paronychia,onychomyCutaneous: intetrigo,paronychia,onychomycosiscosis
Mucocutaneous: perleche, thrush, perianal Mucocutaneous: perleche, thrush, perianal diseasedisease
Chronic: mucocutaneous candidiasis, guanChronic: mucocutaneous candidiasis, guanulomatous diseaseulomatous disease
Systemic: fungemia ,endocarditis,pulmonaSystemic: fungemia ,endocarditis,pulmonary infection,urinary tract infection, meningiry infection,urinary tract infection, meningitis, endophthalmitis tis, endophthalmitis
YeastsYeastsRound to oval, single cells which Round to oval, single cells which reproduce by budding reproduce by budding
Infections with Candida usually occInfections with Candida usually occur when there is some alteration in:ur when there is some alteration in:
Cellular immunityCellular immunity Normal FloraNormal Flora PhysiologyPhysiology
CANDIDIASISCANDIDIASIS
SkinSkin VaginitisVaginitis Urinary tract Urinary tract Mucous membranesMucous membranes SepticemiaSepticemia Endocarditis Endocarditis PneumoniaPneumonia
CANDIDIASISCANDIDIASISThe fourth most common nosocomial The fourth most common nosocomial
bloodstream infection.bloodstream infection.
Clinical SpecimensClinical SpecimensCandidaCandida
SputumSputum Scrapings from lesionsScrapings from lesions Blood smearsBlood smears Vaginal dischargeVaginal discharge UrineUrine FecesFeces
TherapyTherapy
Amphotericin BAmphotericin B NystatinNystatin KetoconazoleKetoconazole FluconazoleFluconazole ItraconazoleItraconazole
CryptococcosisCryptococcosis
A sub-acute or chronic infection A sub-acute or chronic infection which may affect the lungs or skiwhich may affect the lungs or skin but most commonly manifests n but most commonly manifests as a meningitisas a meningitis
Serological Tests
Cryptococcosis
•Indirect fluorescent antibody•Tube Agglutination•Latex Agglutination (measures antigen)