Mycology - Exam 3 Flashcards
fungi characteristics
no chlorophyll/photosynthesis, nucleus (eukary), produces spores, cellulose, chitin, reproduction: asexual (imperfect), sexual (perfect), heterotrophs (aerobic & facultative anaerobic)
beneficial effects of fungi
decomposition, biosynthetic factories, antibiotics, model organisms, recombinant DNA technology, edible, nutritional supplements, flavor, alkaloids, malaria control
harmful effects of fungi
destruction, diseases, toxins, spoilage, damage
fruit rot is also called
botrytis
fungi can also be biocontrol agents against insect pests
white muscardine disease
3 types of poisonous mushrooms
death cap, liberty cap “magic mushroom”, fly agaric
fungi rigid cell wall contains
glucan, mannan, chitin; sterols, 80s ribosomes
most common body structures are
multicellular filaments (mold) and single cells (yeast)
dimorphic shape means
both mold & yeast
mold: vegetative mycelium
inside, provides support, absorbs nutrients
mold: aerial/reproductive mycelium
support the fruiting bodies/reproductive structures
thallus/mycelia: what are the 2 types of hyphae within it
septate & non septate
hyphae
long filaments of cells joined together
yeast structure
nonfilamentous, unicellular, spherical, oval, budding
what are pseudohyphae
when yeast buds fail to detach
dimorphic fungi change from
mycelial form to yeast due to temperature shifts
sexual reproduction
2 haploids, meiosis
asexual reproduction
most common, effective, mitosis, sporulation, fragmentation, budding, gametangium
example of a pathogenic fungi
ringworm
opportunistic fungi
seldom cause disease unless something is underlying allows for it to happen
in the parasitic state, only ________________ are seen
hyphae & arthrospores
routes of entry
nasal, lungs, blood vessels, stomach, intestines, skin
deep mycoses
systemic: brain, lungs, heart, spleen, liver, kidney, cutaneous
superficial mycosis
outer skin layer, no immune response, caused mostly by yeast i.e.: tinea versicolor & white/black piedra
cutaneous mycosis “dermatophytoses”
epidermal layers, evoke immune response, i.e.: ringworm, athlete’s foot, jock itch
subcutaneous mycosis
chronic infection of subdermal tissues
deep/systemic mycosis
mostly originating in the lung by inhalation caused by virulent dimorphic fungi i.e.: valley fever, cave disease, blasto
blasto
systemic fungal disease caused by inhalation of spores from sandy soil, decaying wood, etc.
tinea versicolor
yeast that naturally occurs on the skin, overpopulates causing white blotches on skin
opportunistic mycosis caused by
numerous fungi widespread in nature
4 common fungal infections in animals
ringworm, aspergillosis, candidiasis, blastomycosis
opportunistic mycosis: candidiasis
most common one, can be superficial or deep, alimentary or IVC portal of entry for deep, predisposing factors: chemo, long term antibiotic use, steroids
antifungal agent
selectively eliminates fungal pathogens from a host with minimal toxicity to the host
polyene antifungal drugs
amphotericin, sterols, cell membrane
azole antifungal drugs
fluconazole, inhibit cytochrome enzymes involved with biosynthesis of ergosterol
allylamine & morpholine antifungal drugs
terbinafine, inhibit ergosterol biosynthesis
antimetabolite antifungal drugs
inhibit DNA & RNA synthesis
mycotoxins
toxic secondary metabolites produced by fungi, colonize crops, alphatoxins
rye mold produces
Claviceps purpurea, ergot which leads to ergotism (convulsive symptoms, Salem Witch trials), i.e.: rye, barley, cereal
aspergillus produce
alphatoxin
dermatophytes
parasitizing only keratinized epidermal structures, zoonotic, human/animal/soil resevoir i.e.: ringworm
ways to treat fungal infections
isolate infected animals
lime sulfur/miconazole shampoo
clip hair
itraconazole, fluconazole, griseofulvin, terbinafine
toss contaminated bedding, clean grooming equip.
no vax in dogs/cats yet
what 3 things regulate dimorphism
pH, [CO2], temperature
fungal diseases classified by
mode of entry & degree of tissue involvement
aspergillosis common in which animals
cattle, horse, poultry
which 3 fungi can cause ringworm
microsporum, trichophyton, epidermophyton
microsporidia are what type of parasites
obligate intracellular protozoans
microsporidians infect what animals most
arthropods and fish
microsporidian are related to
fungi
T/F microsporidia are spore-forming
True
examples of horizontal transmission
adult bees ingest spores as result of comb cleaning OR fish and shrimp exposed to microsporidia spores via gut or gills
example of vertical transmission
direct transfer of infection from parent to progeny (offspring)
