chapter 22 Flashcards
Primary Mycoses: Histoplasma Capsulatum
Main biological features
-dimorphic
-white or brown hairlke 35c, creamy white 37c
-ohio valley fever
-eastern and central U.S., nitrogen rich moist soil
Clinical Manifestations
-histoplasmosis(ohio vally fever)
-primary lung, cough, fever, malaise, systemic(disseminates)
Mechanism of Disease
-spherule in lung containing endospore
-spores germinate in lungs(yeast) absorbed by macrophages which break and spread
Transmission
-endospores(inhaled conidia)
-cave explorers, gardeners, occupational, children, elderly, immunosuppressed
Prevention
-masks, protective clothing
Treatment
-antifungals, amphotericen B, flucytosine, azoles, mystatin
Primary Mycoses: Coccidioides immitis(valley fever)
Main biological features -dimorphic, asexual -hyphae in environment, yeast in cells -endemic, southwest, hot areas Clinical Manifestations(40% show symptoms) -coccidioidmycosis(20% show serious infection), fever, malaise, flulike, fungoma, scar tissue, desiminate, to CNS -7% disseminates Mechanism of Disease -fungoma, arthrospores create spherules create nodules in lungs Transmission -endospores(10) -african, asians, phillipines, occupational, 3rd tri preg. Prevention -masks, protective clothing Treatment -antifungals -good prognosis
Primary Mycoses: Blastomycose dermatitidis
Main biological features -dimorphic -converts to yeast in cells -exclusive eastern US, soil Clinical Manifestations -blastomycosis -coughing, fever, malaise, joint pain, CNS, meninges, 50% disseminate Mechanism of Disease -(lung problems)dark tumor like vegitation/scar tissue, creates lesions in dissemination Transmission -endospores(10-100) -males, campers, farmers 3to 1 male to female Prevention -mask, protective clothing Treatment -antifungals -good prognosis
Primary Mycoses: Paracoccioide brasillensis
Main biological features -dimorphic -central/south america, -dead plants, remote areas Clinical Manifestations -paracoccidioimycosis, frequently affects lymph nodes when dissemination occurs -lung infection Mechanism of Disease -spore germination in lungs Transmission -endospores -ag workers, poor nutrition, immnocompromised Prevention -masks, protective clothing -no vaccine Treatment -antifungals -usually benign infection low mortality
Subcutaneous mycoses: Sporthrix schenkii
Main biological features
-dimorphic
-tropics, africa, australia, latin america
-plants decaying wood
Clinical Manifestations
-sporatrichosis
-does not disseminate unless immunosuppressed
-rare contraction
Mechanism of Disease
-penetrates skin, forms nodule, spreads to nearby lymph nodes
Transmission
-cutaneous penetration
-elderly gardeners, HIV gardeners, occupational
Prevention
-protective clothes
Treatment
-antifungals, hot packs(organism does not survive well in heat)
Cutaneous Mycoses Tinea Capitis Tinea barbae Tinea coporis Tinea cruris Tinea pedis Tinea manuum Tinea unguium
Cutaneous Mycoses
-dermatophtoses- ringworm and tinea
-infection promoted by hardiness of dermatophyte spores, presence of abraded skin, and intimate contact
-mechanism is long infection followed by localized infection and allergic reactions to fungal proteins
-resivoir animals, humans, soil
treatment- topical antifungals
Tinea capitis- scalp, head regions
Tinea barbae-beard, china of males, from animals
Tinea coporis-body occurs in inflamed rings
Tinea cruris-groin, jock itch, scrotal region
Tinea pedis-ringworm of feet, sole, public surface
Tinea manuum-ring worm of hand, btwn digits, public surface
Tinea unguium- under the nails of hands/ feet
Superficial Mycoses
Tinea versicolor (caused by Malassezia furfur)
-symptoms- mild, chronic scaling, mottling of skin, also implicated in psoriasis, folliculitis, and seborrheic dermatitis(no complications, anti fungal)
White piedra(caused by Tichosporon biegelli)
-symptoms- white colored mass, effects scalp, pubic, axillary hair(anti fungal)
Black piedra(caused by Piedraia hortae)
-symptoms- dark brown to black gritty nodules on scalp hairs
Opportunistic Mycoses: Candida Albicans
Main biological features -primarily parasitic --normal flora of oral cavity, genitalia, large intestine or skin of 20% of humans -70% of nosocomial infections Clinical Manifestations -thrush -vulvovaginal yeast infection -cutaneous candidiasis(diper rash burns) -oncomycosis -chaffing -can disseminate Mechanism of Disease -budding yeast cell, pseudohyphae, hyphae Transmission -direct contact -IV drug users, cancer patients, bone marrow transplant patients Prevention -be healthy, and avoid contact Treatment -antifungals/topical antifungals, treat underlying conditions
Opportunistic Mycoses: Cryptococcus neoformans
Main biological features
-encapsulated yeast inhabits soil near pigeon roosts
-no hyphae asexual yeast
Clinical Manifestations
-cryptococcus
-infects lungs leads to cough, fever, and lung nodules
-can disseminate to meninges and brain leading to death
Mechanism of Disease
-little virulence, opportunist in AIDS, cancer, or diabetes patients
Transmission
-contact with soil
Prevention
-protective layers, avoid contact
Treatment
-antifungals amphotericin B and fluconazole
Opportunisitc Mycoses: Pneumocystis (carinii) jiroveci and Pneumocystic Pneumonia
Main Biological Features
-unicellular fungus
-opportunistic fungus causes pneumonia(PCP)
-parasite relatively harmless resident of upper respiratory tract
Clinical Manifestations
-pneumonia in AIDS patients, and other immune suppressed
-inflammatory, cough, fever, shallow respiration
Mechanism of Disease
-opportunistic, rapid moving
Transmission
-droplets between humans
Prevention
-good health, rapid diagnosis
Treatment
-antimicrobials, rapid diagnosis
Opportunistic Mycoses: Aspergilliosis(black mold)
Main biological features -common in airborne soil fungus -no yeast only hyphae Clinical Manifestations -allergies to spores create asthma like symptoms -fungal balls in lungs(can colonize sinuses, ear canals, eyelids, and conjuctiva -can disseminate, invasive can produce necrotic pneumonia, and infection of the brain, heart, and other organs Mechanism of Disease -germinate in lungs and form fungal balls -aflatoxin Transmission -spores Prevention -healthy immune/masks Treatment -antifungals
Fungal Allergies and Intoxications
- fungal spores are common sources of atopic allergies
- seasonal allergies and asthma
- -Farmer’s lung, teapickers’s lung, bark stripper’s disease
- Fungal toxins lead to mycotoxicoses usually caused by ingesting or inhaling toxins
- -aflatoxin toxic and carcinogenic, grains, corn, peanuts, lethal to poultry and livestock, (humans man source in peanut butter)
- Stachybotyrs chartarum- sick building syndrome, severe hematologic and neurological damage, one of most powerful toxins in fungal kingdom, not common, inhalation of hype, low exposure for extended time leads to more symptoms
