Mycology Flashcards

1
Q

How did the discovery of penicillin come about?

A

First antibiotic isolated from fungi - occured during WW1 due to high bumber of slodiers dying from infections.
By Fleming

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2
Q

Symptoms of infection that was experimentally treated by penicillin?

A

Rapidly progressing rash on face, eyes and scalp, high spiking fever

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3
Q

Symptoms of Mucromycosis

A

Eye pain - protuding eye
Black patches - lesions that progress to skin (diagnosable)
Coma due to abscesses in the brain
Death by cardiac arrest

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4
Q

Properties of mucormycosis

A

-Invasive, primitve, rapid progression
-requires exogenous iron
-frequent in diabetics and iron chelation therapy
-highly drug resistant

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5
Q

Overall bad sides of fungi

A

Causes infection, intoxication and allergy

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6
Q

Overall good side of fungi

A

Use in the pharmaceutical industry, food industry, biodegradation….

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7
Q

Species numbers / discovery rate

A

Highly unknow, widespread
thought to be 1.5-12 million species
150,000 identified
discovery rate of 1000-2000 a year

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8
Q

Prokaryotes or eukaryotes? Why

A

Eukaryotic:
-contain nucleus
-protein secretory pathways
-mitochondrion (like animals)
-vaculoes (like plants - no chloroplasts)
-cytoplasmic membraine contrains ergosterol (animals have cholesterol, plants have sterol mix)

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9
Q

Describe the cell wall of fungi (+role)

A

Chitin based, its the exoskeleton of the fungi - different for every fungi, but all chiting based (mostly polysaccharides
Structure, protection, exchange with environment

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10
Q

Properties of the way fungi get their nutrients

A

-Heterotrophs - must absorb nutrients, can’t make them themselves
-no vasculature system - can’t spread their nutrients across their body, so ingest, puke reingest (external digestion)

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11
Q

Sub classes of fungi heterotrophy

A

-Sapotrophs: feed on dead organic matter
-Parasite: need a hsot
-Symbiont: partners with an organism
-Predators: trap and kill other organisms

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12
Q

Two types of fungi

A

Yeasts (gorwth as independent cells) & molds (multinucleated tubes)

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13
Q

Properties of yeast? (cell type, reproduction, transition)

A

Unicellular organism with one nucleus
Reproduction by budding or fission
Environmental signals can trigger transition to hyphae or pseudohyphae

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14
Q

Properties of mold? (cell type and structure)

A

Multicellular, filamentous tubular structure containing multiple nuclei
Hyphae - can contain septa (further branching - septated hyphae) or not (aseptated hyphae) assembled into mycelium

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15
Q

Hyphae definition

A

each of the branching filaments that make up the mycelium of a fungus.

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16
Q

Mycelium definition

A

the mass of branched, tubular filaments (hyphae) of fungi.

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17
Q

Fungal sexuality?

A

Fluid - can be sexual or asexual or parasexual (basically a combo of mitosis and meiosis)

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18
Q

Advantages of asexual reproduction + name of form

A

No need for a partner, maintains valuable genetic combinations
Reproduction by mitosis
Anamorph

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19
Q

Sexual reproduction (name of form + subclasses)

A

By meiosis
Telemorph - can be heterophallic or homophallic

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20
Q

Taxonomy key?

A

phylum -mycota
subphylum -mycotina
class -mycetes

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21
Q

3 main groups of fungi

A

Zoosporic fungi
Zygomycetous fungi
Dikarya subkingdom

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22
Q

General info: zoosporic

A

-primitive aquatic fungi
-not predators
-anchroed via rhizoid strcutre
-spread via zoospores (asexual)

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23
Q

General info: zygomycetous

A

-adapted to life on land
-sapotrophs
-aseptated filamentous fungi
-spead via zygospores &/or sporangiospores

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24
Q

General info: dykaria (2 types

A

-Ascomycota : spread via ascospores and conidia
-Basidiomycota: spread via basidospores
Both -s eptated filamentous fungi or yeast

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25
Two main fungal spore dispersal strategies
Via animals or wind
26
Example of animal attraction (for fungi motility)
Stinkhorn fungus: grows up to 25cm, penetrating, strong produces a sticky spore mass that smells like rotting meat, attracts flies that carry spores
27
Example of animal control (for fungi motility)
Cicadas and fungi - emerge every 13-17 years, infection causes loss of abdomen and fertility, but increased sex drive causing infection by mating attempts
28
How doe fungi use the wind? What type of fungi + explain the process
Sporulation Via basidiospore formation, release and transport (wind uptake) Basidiomycetes
29
What increases the number or spores formed (3)? And their dispersion(2)?
Formation: Number of folds -Gills -Pores -Folds Dispersion: -Increased surface area and elevation
30
Name of basidiospore release process? Explain
Ballistospory - surface tension catapult -Swelling of bullers drop from the apiculus -Contact with the swelling of the water layer over the basidiospore Surface tension causes the basidispore to be flung **preference of mushrooms to humid environments
31
How far can spores travel by the wind? How does it work post release?
cms to kms The air is cooled below the fungi due to water evaporation Gravitational free fall pulls spores into the air convection cell (carried by cold air - pushed along by wind)
32
Is sporulation sexual or asexual?
Generally sexual
33
Name of another fungi based transportation method (other than wind)
Catapulted by osmotic pressure
34
In what major way is fungi still shaping our environment? Name of fungi, process
Cntribution to amphibian mass extinction event Chytrids - dangerous invasive fungi Kills by disurpting skin functions, leading to cardiac arrest
35
What is fuelling the spread of chytrids? Origin | Amphibian mass extinction event
International animal trade Originated in Asia
36
Result of amphibian mass extinction that is contributed to by fungi?
Clsoe to 100 species extinct - chytrids are largest threat to a animal diversity
37
What effect does the amphibian mass extinction event have on human population?
Frogs have a positive effect on human disease by consuming parasitic infections that reside in bugs
38
Alberta: effect of fungi on plants
Dutch elm disease (fungal disease) spreads through the forst in Alberta **Blue stain fungus Spread by beetle carries that burrow into the trees, spreading fungal spores Fungus colonizes the tree phloem and sap, leading to death
39
Mont-royal: effect of fungi on plants?
Removal of trees to prevent illegal behaviour Degradation of mountain Replanting with fast growing norway maples - susceptible to tar spot (fungal disease) Predatory - norwegian maples displace native trees
40
What is white nose syndrome?
Fungal infection living in bats (hosts) Mycovirus causing 5 mill bat deaths per year *no mass mortality in europe Infects during hibernation, controlled during waking, takes back over when bats go back to sleep
41
Relevance of bats to the food industry? (+ relationship to fungus)
300++ fruit trees depend on bats for pollinization - white nose syndrome is not yet reported to have crossed over Insect population control issue due to mass mortality of bats
42
Effect of bat mass mortality on human health?
Decreased bats Increased insect control issue Increased pesticide usage Increased infant mortality
43
Relationship between monocultures and fungal infections? Example?
-Monocultures are prone to fungal infections due to being genetically uniform and concentrated in specific areas, which can lead to fungal epidemics. -Banana monoculture (herbs, soproduce fruit withot fertilization, so not sexual reproduction, so no genetic diversity) 1) One banana species type was spread worldwide (gros michel) 2) decimated by TR1 from soil fusarium wilt) - clogging of roots and xylem vessels -> loss of vasculature -> plant wilting and death 3) Same story with cavendish, death by TR4
44
What is wheat rust?
Basidiomycota, affects wheat in the summer (asexual reproduction) swtiches hsot for the rest of the year to barberry plants (sexual reproduction) Widespread destruction of wheat crops in the UK Solution: removal of barberry bushes (worked) But conservationists replanting barberry for insect survival have brought it back
45
What is mycorrhizal fungi?
Micorrhizae = symbiotic relationship between plants and fungi 80% of plants, usually with glomeromycotina (zygomycetous) Increases nutrient access to roots
46
What are the 4 types of mycorrizhal interactions?
Arbuscal & ectomycorrhizae (main) Orchid & ericoid (specific)
47
Explain arbuscal and ectomycorrhizae fungi interaction
Fungal structures cover the root (diff strcutres for the two types but same idea): exchange zone Plants provide C to fungi Fungi improve the wate and mineral assimilation
48
What do myccorhizal fungi secrete and what does it do?
Secretion of glomalin (hydrophobic glycoprotein) into soil Improves soil structure, carbon sequestration, water flow and availability, biodiversity, heavy metal adsorption....
49
Link between mycorrhizal fungy and immunity?
(Still in plants btw) Pathogen presence prevention Stimualtes plants general health and metabolic activity Stimulates plant defences
50
Grey mold - effect on food industry + name
Botrytis (-) 10 billion dollars in crop loss (+) Southern france wine (Sauternes) : infection weakens the skin allowing for water evaporation and sugar concentration *must be picked at exactly the right time
51
Three types of grapes in Sauternes wine
-Semillion (main grapes) -Sauvignon blanc (acidity) -Muscadelle (floral note - easily infected by grey mold)
52
Cheese and fungi?
Blue cheese- fungi is critical for maturation by proteolysis of dairy proteins an dlipids, with falvour coming from the secretion of seconday metabolites
53
Process for obtaining secondary metabolites? Why?
Sexual reproduction of penicilling to increase cheese variety
54
Angel death? Toxin type, location, properties, lethal dose, cause of death
-Contains cyclopeptide toxins (amatoxins) -Quebec -Heat stabke, unaffected by drying -Responsible for almost all mushroom poisoning -0.1mg/kg (with up to 15mg per cap -Inhibits RNA pol II (protein synthesis inhibition) - liver failure
55
Two mushroom type causing psychoactive toxins? Where do they impact?
Psilocybin and psilocin Impact bladder, GI tract, muscles as well as the brain (effect on perception)
56
How does psilocybin work? Used in clinical trials for?
Agonist at cortical serotonin 5-HT 2A receptor (mimics serotonin) Depression and PTSD
57
What psychoactive fungus is hosted by rye? What can it be combined with to make _____
Ergot fungus: lysergic acid can be combined with diethylamine to make LSD
58
What is ergot fungus hosted by? History of the psychoactive drug?
Rye Link to the salem with trials
59
Napoleon and fungus?
Died of arsenic poisoning caused by fungus Cupric arsenic + fungi allowing arsenic to be in the air = Gosio's disease
60
Fungi use as medication?
Canadian first nations people use fungi in traditional medicine Secondary metabolites have health benefits for arththritis, headaches, sunscreen, eye drops, nosebleeds (+++)
61
Summary of fungal secondary metabolites?
Extremely diverse group of compounds, exploited for commercial and medical applications Minority still remain as major health and economic concerns
62
Two types of fungal infections (examples)
Superficial - most common, often benign. Common in immunocompetent (e.g. ringworm) Invasive - rare and lethal if untreated, common in immunocompromised (e.g. mucormycosis)
63
What causes Tinea unguium and tinea pedis? Treatment and frequency
Provoked by dermatophytes (tinea) that feed on keratin Unguium: fingernails, 5-10% of the population 3-6months of antifungals Pedis: feet, most common fungal infection in humans, topical antifungal therapy for 10-14 days (often reoccurs)
64
Three possible environmental origins for superficial fungal infections?
Anthropophile, zoophile or geophile
65
What is candida albicans? Progression,where
Superficial fungal infection Yeast cells -> pseudophya -> true hyphae (causes infection) Commensal organism (until morphological switch to virulence) in GI tract, mouth and vaginal flora
66
Three infection types caused by candidas albicans
Oral thrush diaper dermatitis vaginal candidiasis (female) balanitis (male)
67
Three clinical classifications of invasive infections?
Yeasts: systemic disease, pulmonary disease absent or subclinical Molds: primary pulmonary disease with dissemination less common Dimorhpic fungi: pulmonary disease with dissemination as prominent part of the disease (spread)
68
What is candedimia and how does it work? Example? Mortality?
Severe yeast bloodstream infection Yeast reached blood flow to access other organs Generally immunocompromised patients Fatal if untreated - mortality rate of 20-50% Average stay at the hospital 2-8 weeks
69
What are the three strands of cryptococcus yeast infections? Where do they occur from?
Basidiomycota Encapsulated yeast Two common sp From the environment: soil, eucalyptus trees, bird droppings
70
What is cryptococcosis? How do you get it? Treatment? Symptoms?
Invasive yeast infection caused by breathing yests or spores immuno competent and compromised at risk, causes pulmonary infection (25-50% are asymtpomatic) CSF puncture for cryptococcal meningitis
71
What is cryptoccocal meningitis? How does it happen, whats the treatment
fungal infection that affects the brain and spinal cord cryptococcosis sits in macrophages to cross the BBB Disproportionately likely in HIV patients Treatment: 1. Induction (1 week of amphotericin B) 2. Consolidation (high dose of fluconazole) 3. Maintenance (low dose of fluconazole for a year)
72
How did cryptococcus start affecting immunocompetent people?
New species rising from same sex mating (started in Canada)
73
Symptoms + info on cryptococcus gatti
>300 human, >400 animal cases appeared in 1999 causing pneumonia and meningitis in immunocompetent patients infects native trees and soil
74
What are characteristic properties of mold infections? What is the most common type?
opportunistic, aggressive and destructive Aspergillus, causing invasive pulmonary aspergillosis (>80% mortality
75
Most common species of aspergillus + properties
Aspergillus fumigatus Asexual spores are called conidia Inhaled on a daily basis, but generally taken care of by the immune system and the mucociliary elevator
76
What is the progression of aspergillus fumigatus in immunocompromised patients or patients with imapired lung function?
Alveolar infection -> germination -> angioinvasion -> lung propagation
77
Characteristics of dimorphic fungi? Example
Infect immunocompetent people, geographically restricted in range Blastomyces dermatis
78
Explain the infection cycle + symptoms of blastomyces dermatis
Dimorphic fungi Environmental form in wood (major dog pathogen), endemic to great lakes and mississipi valley The host-associated form is a parasitic yeast, starting as a lung infection and disseminating to the blood and then organs Low mortality, but secondary cutaneous infections are common
79
Overall effect of climate change on fungal infections?
Will become increasing more frequent
80
Why are finding antifungals challenging?
Fungi are eukaryotic proteins - there isnt much we can target that wouldn't also target metabolic proteins
81
What are the two targets of antifungals?
The chitin wall and ergosterol
82
What in the chitin wall do antifungals target? Name of the drug family
chitin and beta-1,3-glycan echinocandins
83
What do echinocandins do? Effect on yeast and molds
Cell was inhibitors by inhibiting beta-1,3-glycan First line of defense against active yeast infection- fungicidal effect Fungistatic (stops growth but does not kill) molds
84
How do antifungals target ergosterol? What are the two antifungal families
By blocking ergosterol, membranes become too rigid Polyenes and azoles
85
How do polyenes work? When is it used, dosage
Binds to ergosterol, causing accumulation, making holes in membrane Braod spectrum, used against severe cases of invasive infections 1mg/kg/day every 2-4h *very poor effect on metabolism
86
How do azoles work? effect on yeasts and molds, chemical composition
Inhibit ergosterol synthesis Fungicidal to molds Fungistatic against yeasts contains either an imizadole or a triazole group
87
What is the common feature of all antifungals?
Resistance of fungus to them is increasing
88
What main component of fungi allow them to resist drugs?
Biofilms - protection against outside microorganisms and the environment
89
What is the driving source of resistance to azoles?
The use of azoles to kill mold in agriculture - same as the ones used in medical fiels, and the more its used the more fungi become able to resist azole in all settings
90
What are tehe three categories of priority groups for pahtogens? Published by who?
Critical, high and medium WHO
91
What is the 'superbug' appearing in the critical group? Whats the worry?
Candida auris - massive, rapid global spread since first report in 2009 4 clades, unlikely to be of the same origin due to phylogenetic diversity
92
What is the hypothesis surrounding the origin of candida auris?
Global warming allowed the strain to be more resistant, as well as increased the presence of its ecological niche (rich in salt, antibiotics for resistance, and persisiting on plastic pollutants) brought to rural areas by an unknow animal reservoir, then urban
93
Pathogen in medium group covered in class? Symptoms, affected group, affected region, why is it worrisome
Valley fever: dimorphic fungi (Coccidiodes spp.) Pulmonary + dissemination 40% of people inhaling the spore become symptomatic (high risk to afroamerican and filipino people) Southwest USA - low humidity + high temp Likely to spread with climate change
94
What is disaster microbiology
study of how natural and human-made disasters affect microorganisms, and how these changes impact ecosystems and human health