Micro Finals-fungi Flashcards
Fungi-Key points
- eukaryotic
- non photosynthetic
- cell walls with chitin
- mounds or yeasts
- sexual or asexual (spores) reproduction
- ergosterol in membrane
Zygomycota
- sexual reproduction with zygospores
- asexual reproduction with spores (conidiophores or sporangiospores)
- aseptate hyphae
Basidiomyceta
- sexual reproduction with basidiospores
- rare asexual reproduction
- septate hyphae
Ascomyceta
- sexual reproduction with ascospores
- asexual reproduction with conidia
- septate hyphae
Deuteromycota/fungi imperfecti
- only asexual reproduction known
- sporangiospores
Arthroconidia
Spores by release of hyphae fragmentation
Blastoconidia
Conidia by budding from mother cell
Hyphae or pseudohyphae
Chlamydoconidia
Thick walled spores with storage products
Macroconidia
Large multicelled
Dermatophytes in culture
Microconidia
Small conidia
Some dermatophytes
Phialoconidia
Conidia from Philalides
Flower like
Sporangiospores
Microphone like
Stages of germination/development of hyphae
- Germination of spores
- Swelling, increased metabolic activity
- Tubular projections, branched hyphae
- Maturation
- Lateral branches
- septa formation
- Myecelium
Zygomycota reproduction
- Zygospore production by hyphae fusion
- Zygospore divides into zygote
- Zygote produce sporangium
- Sporangium release + and - spores
- Spores germinate separately
- Production and of new hyphae
Yeast reproduction
- Ascospore budding into zygote
- Sexual or asexual reproduction by budding or conjugation
- a or alpha ascospores
- haploid and diploid spores
Dermatophytes
-affinity for keratinized structures
-macroconidia in cultures
-arthroconidia infective form
-hyphae in tissues
-ringworm lesions
Microsporum, trichopython
Microsporum canis
- White fluffy colonies with yellow/orange/brown edges
- spindle shaped macroconidia with <15 septa, thick walls
Trichopython verrucosum
- white, heaped velvety colonies with pale/white edges
- chlamydospores in chains
Aspergillus
Molds
- pigmented colonies
- respiratory pathogens, aflatoxins
Aspergillus fumigatus
- blue colonies
- phialoconidia in cultures
- respiratory pathogen
- guttural pouch mycosis
Aspergillus flavus
Mold
- green colonies
- phialoconidia in culture
- aflatoxins
Yeasts
-unicellular budding cells
-asexual reproduction with blastoconidia
-ascomycota or basidiomycota
-chlamydospores in in cornmeal
-germ tubes in serum
Cryptococcus, Malassezia, Candida
Cryptococcus
Cryptococcus neoformans -mucopolysaccharide capsule -budding on narrow neck -bird droppings -inhalation of spores -phenoloxidase->melanin, protection from free radicals -respiratory, cutaneous, neural disease -localized granulomas -selective birdseed agar-> red colonies (phenoloxidase) Biohazard cabinet
Malassezia
Malassezia pachydermatis
- shoe shaped cells
- otitis external
- seborrheic dermatitis
Dimorphism fungi
-mounds in environment and culture
-yeast in animal tissues
-opportunistic infections
-inhalation of spores
Blastomyces, Coccoides, Histoplasma, Sporothrix
Blastomyces
Blastomyces dermatitis
- SDA-> white cottony colonies, oval/pear shaped conidia
- BHI/tissues-> thick walled cells, budding on broad base
- canine blastomycosis
Coccoides
Coccoides immitis
- SDA-> white cottony colonies, arthroconidia
- BHI/tissues-> spherules with endospores
- inhalation of spores
- respiratory disease
- coccidiomycosis
Histoplasma
Histoplasma capsulatum -SDA-> white cottony colonies, sunflower like conidia -BHI/tissues-> small oval cells (in macrophages) -inhalation of spores -respiratory disease, diarrhea -histoplasmosis Histoplasma farcinosum -enzootic lynphangitus -resemble B.mallei cutaneous form
Sporothrix
Sporothrix schenkii
- SDA-> dry brown leathery colonies, pear shaped conidia, rosette
- BHI/tissues-> cigar shaped cells
- inoculation under skin
- granulomas and ulcers, lymphocutaneous disease
- sporothricosis
Zygomycetes
Mounds
-sporangiospores “microphones”
-zygomycosis
Mucorales, Mortierellales, Entemophthorales
Mucorales and Mortierellales
“Bread molds”
- microphone like sporangiospores
- ingestion or inhalation of spores
- abortion, pneumonia, intestinal ulcers, enteritis
Entemopthorales
Molds
- spores enter through skin or nasal mucus membranes (respiratory)
- granulomas w. Eosinophilic deposits
- entomopthomycosis
Aflatoxicosis
- Aspergillus flavus
- Aflatoxin B1
- hepatocellular necrosis, decreased liver function
- maize, grain, rice, nuts
Fumosin toxicosis/ mycotoxic leucoencephalomalacia
- Fusarium verticilloides
- fumosin B1
- neurological signs, porcine pulmonary edema
- moldy corn, grains
Ergotism
- Claviceps purpurea
- ergotamine
- convulsions, swelling and lesions of limbs, lameness, gangrene
- ryegrass seeds, rye, barley
Facial eczema
- Pithomyces chartarum
- sporidesmin
- reduced phylloerythrin in liver
- photodynamic lesions
- in pasture
Ochratoxicosis
- Penicillum verdicatum
- ochratoxin A
- renal disease, nephropathy
- cereal grains
Mycotoxic oestrogemism
- Fusarium graminearum
- zearalenone
- vulvar edema, abortion’s
- excreted in milk-> public health risk
- corn, grain, silage
Tremorgenic mycotoxicosis
- Pencillium species
- penitrem A
- inhibits potassium channels of smooth muscle (CSN)
- muscle tremors, rigidity, seizures, recumbents, fainting, unsteady walk
Mold genuses
- Aspergillus
- microsporum
- mucorales
- Mortierellales
- entemophthorales
Yeast genuses
- candida
- Malassezia
- cryptococcus
Dimorphic fungi genuses
- Sporothrix
- Coccoides
- Histoplasma
- blastomyces
