Exam 2 Fungi Flashcards
(24 cards)
Yeast
Unicellular
Reproduce by fission/budding
Daughter cells produce pseudohyphae - have nuclei
Petri dish= ribbed flat pasty/mucoid colonies, bigger than bacteria
EX: crypto coccus noeformans - halo ONLY capsulated
Histoplasma Capsulinum- no capsule
Mold
Multicellular
Spores get picked up by wind
Hyphae= septate & coenocytic multiple hyphae= mycelium
Dimorphic
Thermal dimorphic
Mold and yest
tempo controls
Mold cold 25C
Yeast heat 37C
Importance of hyphae
Form mycelium
Fungi get carbon from organic source
Hyphae tip release enzymes and absorb nutrients
Conidia
Naked spores
Sporangiospores
Spores covered in sporangica (asexual)
Packaged spores
Coccidiodes imitis
Multipartition barrel shaped hyphae (septate)
Dermatophytes
Affect outer most layer of skin Capitis- scalp, lashes, brow Barabe-beard Corporis- smooth skin Cruis-groin Uguium-nails
Non dermatophyte
Infect deeper skin
Subcutaneous
Cutaneous mycoses
Dermatophytes - Tinaes
Subcutaneous mycoses
Common in gardeners— thorn with spore
Sporotrochosis: thorn puncuture/vegetation contaminated with fungi
Opportunistic Fungi’s
Candida - yeast/yeast psuedohyphe inside
Aspergillus - mold/mold
The different subQ mycoses
Lyphocutaneous sporotrichosis: ulcer at site of inf, ulcers along the lymph
Chromoblastomycosis- cauliflower
Eumycotic mycetoma-slow inflam Fibrosis= disfig
Mucormycosis-entomphthoromycosis- phaeohyphomycosis
Endemic dimorphic pathogens
All in soil - require TH1 & CD8 Blastomyces dermatitidis Coccidiodes immitis Paracocciodes brasiliensis Histoplasma capulatum
Opportunistic fungi
Inhalation & Trauma Candida albicans- most common yst Aspergillus fumigatus most common mld Crytococcus neoformans (capsule)= fungalmeningitis Pneumocytis jiroveaci- AIDS
Primary Fungal Infections
All are respitory infections
None X obligate parasites
All dimorphic
Saprobic phase: filamentous septate hyphae in soil & decay veg. Produce airborne inf.
Parasitic phase: grow at 37C & reproduce sexually in host’s respiratory mucosa.
Opportunistic fungal inf
Immunocompetent- high resistance Candida Cryptococcus neoformans (capsule) Aspergillus Pneumocystis jirovecii
Shared virulence factors of 4 primary fungal inf Blastomyces dermititidis Histoplasma capsulatum Coccidiodes immitis Paracocciodes brasiliensis
All respiratory inf -> ingest spores
No obligate parasites -> get inside humans on accident
Dimorphic- saprobic (mold in soil) and parasitic phases (yeast in human)
Blastomyces dermatitidis
Saprobic -mold Parasitic- yeast Need TH1 & CD8 to clear Inhalation of spores Moist soil in river valleys Initial pulmonary dz East coast/ohio/Mississippi river basin Disseminate to bone ,cns, organs Microscopic sputum & antigen detection
Coccidioides Immitis
Arthrospores/arthroconidia - resilient spores Systemic mycosis - desert fever Forms spores in humans Saprobic- mold , parasitic- spherules Dry soil in desert US SW, Mexico, South America Disseminate - skin, jts, bones, cns
Histoplasma caspulatum
Saprobic- yeast, parasitic -mold
2 variants : capsulatum- pulmonary disseminated dz Eastern US and Latin America
Duboisii- skin bone lesions tropics of Africa
Nitrogen rich soil bird/bat dropping
Candida SP
Pathogenesis- GI tract, vagina, moist skin endogenous. Colonized surface to blood.. ALWAYS a yst. Single cell, forms psuedohyphae grows rapidly 1-3 days.
Thrush & vaginitis
FUNGI
Cryptococcus neoformans
ONLY CAPSULE
Pathogen: inhale spores ; pigeon droppings
Virulence: spherical yeast encased in polysaccharide capsule
Initially in lungs disseminates to blood & CNS=meningitis
Antifungal prophylaxis for high risks
Aspergillus
Mold mold
Most common mold (opportunistic) inhalation of spores wide range of disease , WORLDWIDE
Virulence:spores - shower water tank, potted plants
Hypersensitive Rxn, angioinvasive - dissemination to brain heart kidney liver spleen
Dx: mold in tissue, isolation in culture
