Mycology 1 Flashcards

1
Q

Mycology?
* Is the branch of biology dealing with ?; it includes the study of a great number of ?-cellular, ?cellular or microscopic organisms. It includes their ? and ? properties, their taxonomy and uses, plus dangers to ? and animals

  • Fungus?
  • Organism without ?, with nucleus, producing ?; reproducing sexually (perfect) or asexually (imperfect); whose filamentous and branching somatic structures have evolved with cell ? containing ? or ? or both

THINGS BELOW V USEFUL IN DIAGNOSTICS!
D-Glucose units
β(1→#?)-? bonds

CHITIN useful for specific staining i.e. diagnostic (tells that the specific thing could be fungi)

A

Mycology?
* Is the branch of biology dealing with fungi; it includes the study of a great number of multi-cellular, unicellular or microscopic organisms. It includes their genetic and biochemical properties, their taxonomy and uses, plus dangers to humans and animals

  • Fungus
  • Organism without chlorophyll, with nucleus, producing spores; reproducing sexually (perfect) or asexually (imperfect); whose filamentous and branching somatic structures have evolved with cell wall containing cellulose or chitin or both

(Chitin exists in the shells of arthropods such as crabs, shrimps, and insects and is also produced by fungi and bacteria
cellulose in many plant cell walls)

D-Glucose units (each subunit)
β(1→4)-glycosidic bonds

CHITIN useful for specific staining i.e. diagnostic

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2
Q

Fungus (pl. Fungi)

  • Greek “mykes” – mushroom
  • ~ 1 ? different species of fungi
    Only ~ ? are described
  • Taxonomy of fungi is in a state of ?
A

Fungus (pl. Fungi)

  • Greek “mykes” – mushroom
  • ~ 1 million different species of fungi
    Only ~ 70,000 are described
  • Taxonomy of fungi is in a state of flux (continuous change)
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3
Q
A

microspora: sister groups of FUNGI so are up there with fungi (placed them down there before; reasoning maybe mitochondrial endosymbiosis; so might have been there before mitochondria but later found out that they don’t have mitochondria or peroxisomes, they don’t have the machinery to do it and are parasites).

(online: Molecular phylogenetic data indicate that the Microsporidia are related to the Fungi, lack mitochondria (earlier thought to have mitochondria) and are not primitive eukaryotes)

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4
Q

**UNIKONTS

(charles darwin, mushroom and amoeba, obvious grouping - in UNIKONT)

Unikonts include amoebozoa and ** ? ** (FUNGI and animals)

Fungi are a relatively ? evolved taxa, at least compared to most other potential veterinary and medical pathogens, including ? ?

Stramenopiles: (?) Algae, kelp to diatoms & Oomycetes (? molds)

Excava”te”s: amitochondriate flagella”te”s, amoeboflagellates, Euglenozoa

Forams: large group of amoeboid ? with reticulating pseudopods

Cercozoa: amoeboids and flagellates that feed by means of filose pseudopods, includes Halposporidians

A

**UNIKONTS

(charles darwin, mushroom and amoeba, obvious grouping - in UNIKONT)

Unikonts: amoebozoa and ** OPISTHOKONTS ** (FUNGI and animals)

(- The opisthokonts are a broad group of eukaryotes, including both the animal and fungus kingdoms. The opisthokonts, previously called the “Fungi/Metazoa group)

Fungi are a relatively highly evolved taxa, at least compared to most other potential veterinary and medical pathogens, including protist parasites

Stramenopiles: (Heterokonts) Algae, kelp to diatoms & Oomycetes (water molds)

Excavates: amitochondriate flagellates, amoeboflagellates, Euglenozoa

Forams: large group of amoeboid protists with reticulating pseudopods

Cercozoa: amoeboids and flagellates that feed by means of filose pseudopods, includes Halposporidians

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5
Q

in the chart, now microsporidia in the proper place along with fungi!

Oomycetes in stramenopiles will be talked about later - these look like fungal diseases, some are zoonotic!

are there more beneficial or harmful effects of fungi?

Beneficial Effects of Fungi
1. * ? * - nutrient and carbon recycling.
2. * ? * factories. The fermentation property is used for the industrial productionof alcohols, fats, citric, oxalic and gluconic acids.
3. Important sources of * ? , such as Penicillin.
4. * ? * for biochemical and genetic studies. eg: Neurospora crassa
5. Saccharomyces cerviciae is extensively used in **
? ***, which includes the Hepatitis B Vaccine.
6. Some fungi are * ? * (mushrooms).
7. Yeasts provide ? supplements such as vitamins and cofactors.
8. Penicillium is used to * ? * Roquefort and Camembert cheeses.
9. Ergot produced by Claviceps purpurea contains medically important ? that help in inducing uterine contractions, controlling bleeding and treating ?.
10. Fungi (Leptolegnia caudate and Aphanomyces laevis) are used as biocontrols against ? in paddy fields and thus help in ? control.

IMP all!! HARMFUL EFFECTS OF FUNGI
1. ? of food, lumber, paper, and cloth.
2. Animal and human ?, including allergies.
3. ? produced by poisonous mushrooms and within food (Mycetism and Mycotoxicosis).
4. Plant ?.
5. ? of agriculture produce such as
vegetables and cereals.
6. ? the products such as magnetic tapes
and disks, glass lenses, marble statues, bones and wax.

A

are there more beneficial or harmful effects of fungi? - MORE BENEFICIAL!

BENEFICIAL EFFECTS OF FUNGI

emphasized
- recombinant DNA technology typically with yeasts which are fungi!
- edible, nutritional supplements
- malaria control
- Fungi (Leptolegnia caudate and Aphanomyces laevis -> THESE 2 ARE ACTUALLY “STRAMENOPILES” and not fungi) are used as biocontrols against mosquito larvae in paddy fields and thus help in malaria control.

BENEFICIAL Effects of Fungi
1. * decomposition * - nutrient and carbon recycling.
2. * biosynthetic * factories. The fermentation property is used for the industrial productionof alcohols, fats, citric, oxalic and gluconic acids.
3. Important sources of * antibiotics , such as Penicillin.
4. * model organisms * for biochemical and genetic studies. eg: Neurospora crassa
5. Saccharomyces cerviciae is extensively used in **
recombinant DNA technology ***, which includes the Hepatitis B Vaccine.
6. Some fungi are * edible * (mushrooms).
7. Yeasts provide nutritional supplements such as vitamins and cofactors.
8. Penicillium is used to * flavour * Roquefort and Camembert cheeses.
9. Ergot produced by Claviceps purpurea contains medically important alkaloids that help in inducing uterine contractions, controlling bleeding and treating migraine.
10. Fungi (Leptolegnia caudate and Aphanomyces laevis) are used as biocontrols against musquito larvae in paddy fields and thus help in malaria control.

IMP all!! HARMFUL EFFECTS OF FUNGI
1. DESTRUCTION of food, lumber, paper, and cloth.
2. Animal and human DISEASES, including allergies.
3. TOXIN produced by poisonous mushrooms and within food (Mycetism and Mycotoxicosis).
4. Plant DISEASES.
5. SPOILAGE of agriculture produce such as
vegetables and cereals.
6. DAMAGE the products such as magnetic tapes and disks, glass lenses, marble statues, bones and wax.

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6
Q

Post-harvest fruit-rot “botrytis” - Botrytis cinerea

From ancient Greek
‘botrys’ meaning ? and
‘itis’ for ?

And then a lot of the produce, like lemons, get botrytis too (a lot of them are then waxed and treated and pulses of crap on them that, you know, make them so attractive to eat anymore

Corn smut: In Mexico, corn smut is known as huitlacoche

Corn smut is a plant disease caused by the pathogenic fungus Ustilago ? that causes ? (a fungal disease) on maize.
Considered a big problem in parts of the north, and has been almost eradicated from most corn crops.
In Mexico is a ?!!
When grown in the lab on media, it behaves like ?, forming ? cells.

A

From ancient Greek
‘botrys’ meaning grape and
‘itis’ for disease so grape disease

And then a lot of the produce, like lemons, get botrytis too (a lot of them are then waxed and treated and pulses of crap on them that, you know, make them so attractive to eat anymore

E.G. OF FUNGI DAMAGING THINGS
Corn smut: In Mexico, corn smut is known as huitlacoche

Corn smut is a plant disease caused by the pathogenic fungus Ustilago maydis that causes smut (a fungal disease) on maize.
Considered a big problem in parts of the north, and has been almost eradicated from most corn crops.
In Mexico is a delicacy!!
When grown in the lab on media, it behaves like yeast, forming single cells.

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7
Q

FUNGI PRODUCE INTERESTING COMPOUNDS! - here e.g. of health product

Fungi produce toxins, mycotoxins

the chemical formula is called “?” - extracted from ? mushrooms:
- given to people with ?, high LDL or HDL?

A

FUNGI PRODUCE INTERESTING COMPOUNDS!

Fungi produce toxins, mycotoxins

the chemical formula is called “statin” - extracted from oyster mushrooms:
- given to people with high blood cholestrol level, high LDL

So the low-density lipoprotein (LDL) is considered to be the poor one versus HDL (where cholesterol is sent to kidneys? to be eliminated)

Name in pic: O shouldn’t be capatilize

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8
Q

FUNGI ALSO PRODUCE TOXINS!

Poisonous mushrooms

  1. Amanita ? (? cap)
  2. Psilocybe semilanceata (? cap or ‘?’)
  3. Amanita ? (fly ?)
A

FUNGI ALSO PRODUCE TOXINS!

Poisonous mushrooms

  1. Amanita phalloides (Death cap) - phalloi”de”s “De”ath cap
  2. Psilocybe semilanceata (liberty cap or ‘magic mushroom’) - will mess w ur mind
  3. Amanita muscaria (fly agaric) - v disney-ish looking (the nordic tribes used to eat this and it made them berserk/crazy: northern fairytales) - not as fatal as first one
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9
Q

Chlorophyllum molybdites, which has the common names of ? parasol, ? parasol and ‘?’

The Edible Parasol Mushroom/Lepiota (Macrolepiota procera)

(are green-spored parasol so if put on paper then spores come out (yellowishing thing in bottom left image))

A

Chlorophyllum molybdites, which has the common names of false parasol, green-spored parasol and ‘vomiter’

THE FALSE PARASOL OR GREEN-SPORED MUSHROOM IS A POISONOUS MUSHROOM THAT IS THE MOST COMMON CAUSE OF MUSHROOM POISONING IN THE US!

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10
Q

Entomopathogenic Fungi as Biocontrol Agents against insect pests

White ? disease

Fungus’s ? land on insects and infects insect and produce ?, then ? are released and infect another host or persist in ?!

fungus:
Metarhizium anisopliae (not specific)
Beauveria bassiana

A

Entomopathogenic Fungi as Biocontrol Agents against insect pests (“ent”omapathogenic.. ent sounds like ant)

White muscardine disease

Fungus’s spores land on insects and infect insect and produce spores, then spores are released and infect another host or persist in the soil!

These are considered bio-pesticides as killing them naturally, however, they aren’t specific and are less targeted thus similar to chemical pesticides.

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11
Q

Just know that there’s lots of diff. groups (chitridiomycota: amphibians) and reminder what heterotroph is! SEE PIC in ans.

Heterotroph: an organism that must ingest or absorbs organic ? in order to be able to produce ? and synthesize compounds to maintain its ?

A

Heterotroph: an organism that must ingest or absorbs organic C in order to be able to produce energy and synthesize compounds to maintain its existence!

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12
Q

General characteristics of fungi

  • Fungi are ** prokaryotic or eukaryotic? ** organisms: cells contain ? cell organelles including nuclei, mitochondria, Golgi apparatus, endoplasmic reticulum, lysosomes etc.
  • IMP! Their rigid Cell Wall contain: ** ?, ? and ?** – ?-glucans are medically important as
    they are a drug target for some anti fungals (prevents osmotic lysis and protects against mechanical injury and entrance of harmful macromolecules); (non-motile)
  • Cell membrane contain ** ? (IMP! ?) **
  • 80S ribosomes

in fungi which sterol is present? <- this is targeted!

A

General characteristics of fungi

  • Fungi are ** eukaryotic ** organisms: cells contain membrane bound cell organelles including nuclei, mitochondria, Golgi apparatus, endoplasmic reticulum, lysosomes etc.
  • IMP! Their rigid Cell Wall contain: ** GLUCAN, MANNAN and CHITIN ** – beta-glucans are medically important as they are a drug target for some anti-fungals (prevents osmotic lysis and protects against mechanical injury and entrance of harmful macromolecules); (non-motile)
  • Cell membrane contain ** sterols (IMP! ERGOSTEROL specifically) **
  • 80S ribosomes

in fungi the sterol is = ERGOSTEROL <- this is targeted!

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13
Q

General characteristics of fungi
* The most common body structures are ? filaments (?) and ? cells (?)
* Some species grow as either filaments or yeasts; others grow as both (dimorphic)
* Reproduction- ? (perfect) and ? (imperfect)
* produce ?

A
  • The most common body structures are multicellular filaments (molds) and single cells (yeasts)
  • Some species grow as either filaments or yeasts; others grow as both (dimorphic)
  • Reproduction- sexual (perfect) and asexual (imperfect)
  • produce SPORES!
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14
Q

Which among the 2 contain heterotrophs?
FUNGI and Bacteria

A

BOTH are heterotrophs

fungi:
heterotrophs; aerobic, facultatively anaerobic

bacteria:
Heterotrophic, autotrophic, photosynthetic; aerobic, anaerobic, facultative anaerobic

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15
Q

ISOLATION OF FUNGAL ORGANISMS

Most grow in ? media at 20-25 C
- sabouraud’s dextrose (SabDex) agar

Some grow in Blood agar in the yeast phase at 37 C

(Fungi grow in all sorts of different rates so what grows might not be the pathogen u are looking for, might not be the pathogen u want
yeast phage in the red one so this would be more mammalian body temp. i.e. 37 C and other green one is more ambient temp.)

  • Fungi can form 2 types of colonies:
    a) ? - mold
    b) ? form - yeast (superfically look more like bacteria but smell yeasty)
A

Most grow in common media at 20-25 C
- sabouraud’s dextrose (SabDex) agar

  • Fungi can form 2 types of colonies:
    a) filamentous - mold
    b) yeast form - yeast (superfically look more like bacteria but smell yeasty)
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16
Q

Mold

** IMP Macroscopic **:
- ? rate (fast, moderate and slow)
- ? appearance: texture and shine
- presence of ?: colony colour
- colony ?

Mold - ** IMP Microscopic **
* Vegetative mycelium: develops inside the ?; provides support, and absorbs ?

Fungal filaments Hypha = Growth of a hypha from a spore (see pic)

mass of hyphae collectively make up the ?

  • Reproductive mycelium: differentiation to support the ? bodies, ?
  • “two kinds of hyphae:” IMP!! (-> this also helps in DIAGNOSTICS! if mixed infection then both types of hypha present).

(a) Septate hypha
(b) Non septate hypha

✓The septa (cross walls) divide the hyphae into ? but not into cells (can see in image)

✓In some groups nuclei and/or ? can flow through a hole or pore in the center of these ?

A

Mold

** Macroscopic **:
- growth rate (fast, moderate and slow)
- colony appearance: texture and shine
- presence of pigment: colony colour
- colony morphology

Mold - ** IMP Microscopic **
* Vegetative mycelium: develops inside the substrate; provides support, and absorbs nutrients

Fungal filaments Hypha = Growth of a hypha from a spore (see pic)

mass of hyphae collectively make up the Mycelium

  • Reproductive mycelium: differentiation to support the fruiting bodies, propagules

(in the environmental stage, it’s very robust,
It can be in the environment for a long time, but when conditions allow, it will germinate and hyphae will grow from that.
And it’ll be then in some sort of place where it can absorb nutrients and it will go from there.)

  • “two kinds of hyphae:” IMP!!

(a) Septate hypha
(b) Non septate hypha

✓The septa (cross walls) divide the hyphae into compartments but not into cells (can see in image)

✓In some groups nuclei and/or cytoplasm can flow through a hole or pore in the center of these septa!

17
Q

Structures – filamentous –
summary

  • Mold and Fleshy Fungi
  • Body = “? which consists of Hyphae”
  • Hyphae = Long ? of cells joined together
  • Vegetative hyphae obtain ?
  • Aerial hyphae bear ? structures
  • Mycelium= ? mass of hyphae

(For larger fungi we still have the mycelium in the substrate (underground) and the thing above ground is the ‘fruiting body’ so spores would come out of the gills
- HYPHAE: each of the branching filaments that make up the mycelium of a fungus.
- THALLUS: hyphae joined together)

A

Structures – filamentous –
summary

  • Mold and Fleshy Fungi
  • Body = “thallus”
  • thallus consists of Hyphae
  • Hyphae = Long filaments of cells joined together
  • Vegetative hyphae obtain nutrients
  • Aerial hyphae bear reproductive structures
  • Mycelium= filamentous mass of hyphae
18
Q

Structure - Yeast
* Nonfilamentous ? fungi which are spherical or oval
* Reproduction by ?
* When buds fail to detach are called ?
* e.g. Candida ?

Candidiasis
* Common normal flora of the ? in many animals
* Hence usually a ? organism
* Can become ? during immunosuppression

A

Structure - Yeast
* Nonfilamentous unicellular fungi which are spherical or oval
* Reproduction by budding
* When buds fail to detach are called pseudohyphae
* e.g. Candida albicans

Candidiasis
* Common normal flora of the gut in many animals
* Hence usually a commensal organism
* Can become pathogenic during immunosuppression

19
Q

Yeast - pic

** Dimorphic fungi **
* Change from ? form (at room temperature) to ? (at 37°C or in the tissues of animals)

Dimorphism is regulated by factors such as * ? * (typically), CO2 concentration, ?, and the levels of ? or other ?-containing compounds

FUNGAL REPRODUCTION

Sexual:
* Only demonstrated in most or few? fungi
* * Fusion of two haploid nuclei followed by ** ? ** division of the diploid nucleus *

Asexual:
* Very effective
* Division of nuclei by * ? * (NOT ? like for sexual) and subsequent cell division by an individual fungus

Three basic mechanisms of asexual:
* ? followed by germination of
the spores
Aspergillus and Penicillium

  • ?
    Coccidioides immitis
  • ? of ? cells
    Candida and Cryptococcus

Asexual, sexual -> which is most common/more effective?

A

Yeast - pic

** Dimorphic fungi **
* Change from “m”ycelial form (at roo”m” temperature) to yeast (at 37°C or in the tissues of animals)

Dimorphism is regulated by factors such as * TEMPERATURE * (typically), CO2 concentration, pH, and the levels of cysteine or other sulfhydryl-containing compounds

FUNGAL REPRODUCTION

Sexual:
* Only demonstrated in few fungi
* * Fusion of two haploid nuclei followed by ** MEIOTIC ** division of the diploid nucleus *

Asexual:
* Very effective
* Division of nuclei by * MITOSIS * (NOT meiosis like for sexual) and subsequent cell division by an individual fungus

Three basic mechanisms of asexual:
* SPORULATION followed by germination of
the spores
Aspergillus and Penicillium

  • Fragmentation of hyphae * Coccidioides immitis
  • BUDDING of yeast cells
    Candida and Cryptococcus

Asexual, sexual -> which is most common/more effective? ASEXUAL!

20
Q

Fungal diseases (Mycosis)

  • Except for dimorphic fungi and dermatophytes (pathogens); (Dermatophytes cause ringworm) fungi usually or rarely? cause disease in healthy, immunocompetent animals
  • It usually presents as: a ? condition when fungi accidentally penetrate host barriers
  • Those causing disease (A/H) broadly classified as:
  • ? fungi – cause ringworm and more common mycoses (blastomycosis; histoplasmosis)
  • ? fungi – seldom (rarely) cause disease (ass. Immunocompromised individuals)
A

Fungal diseases (Mycosis)

  • Except for dimorphic fungi and dermatophytes (pathogens); (Dermatophytes cause ringworm) fungi rarely cause disease in healthy, immunocompetent animals
  • It usually presents as: a debilitating condition when fungi accidently penetrate host barriers
  • Those causing disease (A/H) broadly classified as:
  • pathogenic fungi – cause ringworm and more common mycoses (blastomycosis; histoplasmosis)
  • oppurtunistc fungi – seldom (rarely) cause disease (ass. Immunocompromised individuals)
21
Q

Factors that may predispose to fungal invasion of tissues:
* Immunosuppression
* Prolonged ? therapy
* ? defects
* Immaturity, ? and malnutrition
* Exposure to heavy challenge of ? spores (e.g. moldy room)
* Traumatized tissue
* Persistent ? on skin surface
* Some ? condition

A

Factors that may predispose to fungal invasion of tissues:
* Immunosuppression
* Prolonged antibiotic therapy
* immunological defects
* Immaturity, ageing and malnutrition
* Exposure to heavy challenge of fungal spores (e.g. moldy room)
* Traumatized tissue
* Persistent moisture on skin surface
* Some neoplastic condition

22
Q

Fungal diseases are classified according to the ? into the host and the ? involvement

for tissue involvement, lot of it is cutaneous:
1. ? (on skin, hair, nails)
2. ? (within skin, hair, nails)
3. ? (beneath skin) - more serious like the one in pic (sporotrichosis)

Deep mycoses can be systemic mycoses - brain, lungs, heart, spleen, liver and kidney

Routes of entry: nasal sinuses, lungs, blood vessels, esophagus, stomach, intestine, skin (spores in air -> clear route of entry, needles -> blood vessels and into skin)

A

Fungal diseases are classified according to the mode of entry into the host and the degree of tissue involvement

for tissue involvement, lot of it is cutaneous:
1. superficial (on skin, hair, nails)
2. cutaneous (within skin, hair, nails)
3. subcutaneous (beneath skin) - more serious like the one in pic (sporotrichosis)

23
Q

Classification of mycosis based upon the area of the body they infect

Superficial
INNER OR OUTER? skin layer - no immune response; caused mostly by ?. e.g. tinea ? (caused by Malassezia furfur); ? piedra (caused by Trichosporon asahii and others); ? piedra (caused by Piedraia hortae)

(tinea versicolor: pigment change in the skin and it’s usually facilitated and it’s in a similar tropical climate with moisture on the skin.)

Cutaneous mycoses (dermatophytoses)
? layers - evoke immune response. (Ringworm, Athlete’s foot, jock itch) caused by * ? * (Trychophytum; Microsporum; Epidermophyton) !
Dermatomycoses are ? diseases due to other fungi like Candida

Subcutaneous mycoses
Chronic infection of ? tissues; may require surgical intervention. e.g. Sporotrichosis (Sporothrix schenckii - Dimorphic fungus); mycetoma (by skin wounds)
(- facilitated by wound!)

Deep/systemic mycoses
Mostly originating in the ? by inhalation caused by virulent * ? * fungi
e.g.,
Coccidioides immitis -> Coccidioidomycosis (? fever)

Histoplasma capsulatum -> Histoplasmosis (? disease)

Blastomyces dermatitides > Blastomycosis
Paracoccidioides brasiliensis

(tinea versicolor: pigment change in the skin and it’s usually facilitated and it’s in a similar tropical climate with moisture on the skin.)

A

Classification of mycosis based upon the area of the body they infect

Superficial
OUTER skin layer - no immune response; caused mostly by yeast. e.g. tinea versicolor (caused by Malassezia furfur); white piedra (caused by Trichosporon asahii and others); black piedra (caused by Piedraia hortae)

(tinea versicolor: pigment change in the skin and it’s usually facilitated and it’s in a similar tropical climate with moisture on the skin.)

Cutaneous mycoses (dermatophytoses)
EPIDERMAL layers - evoke immune response. (Ringworm, Athlete’s foot, jock itch) caused by * dermatophytes * (Trychophytum; Microsporum; Epidermophyton) !
Dermatomycoses are skin diseases due to other fungi like Candida

Subcutaneous mycoses
Chronic infection of subdermal tissues; may require surgical intervention. e.g. Sporotrichosis (Sporothrix schenckii - Dimorphic fungus); mycetoma (by skin wounds)
(- facilitated by wound!)

Deep/systemic mycoses
Mostly originating in the lungs by inhalation caused by virulent * DIMORPHIC * fungi
e.g.,
Coccidioides immitis -> Coccidioidomycosis (valley fever)

Histoplasma capsulatum -> Histoplasmosis (cave disease)

Blastomyces dermatitides > Blastomycosis
Paracoccidioides brasiliensis

(tinea versicolor: pigment change in the skin and it’s usually facilitated and it’s in a similar tropical climate with moisture on the skin.)

24
Q

Common fungal infections in animals

(NOTE: don’t confused microsporidians (mycology II) with microspores!!)

Ringworm (dermatophyte infections or dermatophytoses)
- Causative fungus: ? & ?
- Animals affected: all ? animals and ?

Aspergillosis
- Causative fungus: ?
- Animals affected: ?, ? and ?

Candidiasis
- Causative fungus: ?
- Animals affected: ?, ? and ?

Blastomycosis
- Causative fungus: ?
- Animals affected: ?, ?, ?, ?, occasionally other animals will be affected

A

Common fungal infections in animals

(NOTE: don’t confused microsporidians (mycology II) with microspores!!)

Ringworm (dermatophyte infections or dermatophytoses)
- Causative fungus: Microsporum spp., Trichophyton spp.
- Animals affected: all domestic animals and man

Aspergillosis
- Causative fungus: aspergillus spp.
- Animals affected: cattle, horse and poultry

Candidiasis
- Causative fungus: candida albicans
- Animals affected: dogs, cats and pigs

Blastomycosis
- Causative fungus: Blastomyces dermatidis
- Animals affected: dogs, humans, cats, horses and occasionally other animals will be affected

25
Q

Dermatophytes

Microsporum and Trichophyton

Ringworm – superficial ? infection, commonly caused by the fungus Trichophyton rubrum in humans

there are anthropophillic (man) human reservoirs, zoophilic (animal) dermatophytes, geophillic (soil/environmental) dermatophytes

PATHOLOGY

INITIAL phase: subclinical or mild host response
- hypertrophy of the stratum ? with accelerated keratinization and exfoliation
- ? appearance and some hair loss (alopecia)

LATER phase: more pronounced inflammatory response
- ranges from erythema to vesiculopustular reactions and suppuration
- roughly circular pattern of the lesions and their inflamed margins suggested the terms ? and ?

ringworm usually regresses spontaneously within a few ? or months

A

Dermatophytes

Microsporum and Trichophyton

Ringworm – superficial dermatophyte infection, commonly caused by the fungus Trichophyton rubrum in humans

there are anthropophillic (man) human reservoirs, zoophilic (animal) dermatophytes, geophillic (soil/environmental) dermatophytes

PATHOLOGY

INITIAL phase: subclinical or mild host response
- hypertrophy of the stratum corneum with accelerated keratinization and exfoliation
- scruffy appearance (cat in pic) and some hair loss (alopecia)

LATER phase: more pronounced inflammatory response
- ranges from erythema to vesiculopustular reactions and suppuration
- roughly circular pattern of the lesions and their inflamed margins suggested the terms RINGWORM and TINEA

ringworm usually regresses spontaneously within a few weeks or months

26
Q

dimorphic fungi: u’ve got both yeast like cells and filamentous hyphae

rabbit hole has spores: dog puts head in and gets the spores

blastomycosis or blasto as its often called is a v serious and potentially deadly, systemic fungal disease that can affect dogs, humans and other mammals. Blasto is caused by inhaling the spores of the fungus Blastomycetes dermatitis. B. dermatitis grows as a mold in acidic, organically rich sandy soils, decaying wood and other vegetation!
- not ZOONOTIC or contagious between dogs (needs to be directly taken)

A
27
Q

Opportunistic mycosis

Caused by ? fungi that are widespread in nature e.g. most representative genera: ?

  • Candida ?: Candidiasis
  • Cryptococcus ?: Cryptococcosis
  • ? sp.: Aspergillosis

Opportunistic mycosis: e.g
✓CANDIDIASES

  • candidiases caused by C. ? and other Candida spp.
  • The * most rare or common? opportunistic fungal infection*
  • superficial or deep (not asking a q.)
  • ? may involve the epidermal and mucosal surfaces, including those of the oral cavity, pharynx, esophagus, intestines, urogenital tract
  • The ? tract and ? catheters are the major portals of entry for deep (or visceral) candidiasis
  • The kidneys, ?, spleen, ?, eyes and heart and other tissues are the major organ sites involved in deep or visceral candidiasis
  • The risk factors predisposing to deeply invasive candidiases are protracted courses of broad-spectrum ?, cytotoxic ?, corticosteroids and ? catheters.
A

Opportunistic mycosis

Caused by numerous fungi that are widespread in nature e.g. most representative genera: mycosis

  • Candida albicans: Candidiasis
  • Cryptococcus neoformans: Cryptococcosis
  • aspergillus sp.: Aspergillosis

Opportunistic mycosis: e.g
✓CANDIDIASES

  • candidiases caused by C. albicans and other Candida spp.
  • The * common opportunistic fungal infection*
  • superficial or deep (not asking a q.)
  • superficial candidiasis may involve the epidermal and mucosal surfaces, including those of the oral cavity, pharynx, esophagus, intestines, urogenital tract
  • The alimentary tract and intravascular catheters are the major portals of entry for deep (or visceral) candidiasis
  • The kidneys, brain, spleen, liver, eyes and heart and other tissues are the major organ sites involved in deep or visceral candidiasis
  • The risk factors predisposing to deeply invasive candidiases are protracted courses of broad-spectrum antibiotics, cytotoxic chemotherapy, corticosteroids and vascular catheters.
28
Q

Treatment - antifungal

  • An ANTIFUNGAL agent is a drug that ? eliminates fungal pathogens from a host with minimal toxicity to the host (so wont target host)

IMP - fluorocytosine inhibits DNA/RNA synthesis
- recall structural things in cell wall of fungi including chitin, we use that in diagnostics but not in therapy
- there’s also “beta-glucans” in cell wall (bottom/ below chitin)
- there’s also “ergosterol” which gives membrane its fluidity

** IMP! ? B binds with ergosterol **, a component of fungal cell membranes, forming ? that cause rapid leakage of monovalent ions (K+, Na+, H+, and Cl−) and subsequent fungal cell ?

A

Treatment - antifungal

  • An ANTIFUNGAL agent is a drug that selectively eliminates fungal pathogens from a host with minimal toxicity to the host (so wont target host)

IMP - FLUCYTOSINE inhibits DNA/RNA synthesis
- recall structural things in cell wall of fungi including chitin, we use that in diagnostics but not in therapy
- there’s also “beta-glucans” in cell wall (bottom/ below chitin)
- there’s also “ergosterol” which gives membrane its fluidity

** IMP! Amphotericin B binds with ergosterol **, a component of fungal cell membranes, forming pores that cause rapid leakage of monovalent ions (K+, Na+, H+, and Cl−) and subsequent fungal cell death

29
Q

Antifungal Drug Mechanisms

✓**Polyene Antifungal Drugs
* Amphotericin B, nystatin, and pimaricin interact with * ? (Ergosterol) in the cell ? *

✓ Azole Antifungal Drugs
* Fluconazole, itraconazole, and ketoconazole inhibit cytochrome P450-dependent enzymes involved in the biosynthesis of ? **

✓Allylamine and Morpholine Antifungal Drugs
* Allylamines (naftifine, terbinafine) inhibit ? biosynthesis

✓Antimetabolite Antifungal Drugs
* 5-Fluorocytosine acts as an inhibitor of both ? and ? synthesis

A

Antifungal Drug Mechanisms

✓**Polyene Antifungal Drugs
* Amphotericin B, nystatin, and pimaricin interact with * sterols (Ergosterol) in the cell membrane *

✓ Azole Antifungal Drugs
* Fluconazole, itraconazole, and ketoconazole inhibit cytochrome P450-dependent enzymes involved in the biosynthesis of ergosterol **

✓Allylamine and Morpholine Antifungal Drugs
* Allylamines (naftifine, terbinafine) inhibit ergosterol biosynthesis

✓Antimetabolite Antifungal Drugs
* 5-Fluorocytosine acts as an inhibitor of both DNA and RNA synthesis

30
Q

MYCOTOXINS

Are toxic secondary metabolites produced by fungi, that are structurally ?, not essential to fungal growth and produced periodically under fungal ?

The term ‘mycotoxin’ is usually reserved for the ? chemical products produced by ?-fungi that readily colonize crops

They can contaminate a variety of ? feed and food leading to nutrient ? and producing ? effects on animal and human health

One fungi/mold species may produce many different ?, and several species may produce the same mycotoxin

  • ? * are a type of * ? * produced by Aspergillus spp.
A

MYCOTOXINS

Are toxic secondary metabolites produced by fungi, that are structurally diverse, not essential to fungal growth and produced periodically under fungal stress

The term ‘mycotoxin’ is usually reserved for the toxic chemical products produced by micro-fungi that readily colonize crops

They can contaminate a variety of mixed feed and food leading to nutrient losses and producing adverse effects on animal and human health

One fungi/mold species may produce many different mycotoxins, and several species may produce the same mycotoxin

  • Aflatoxins * are a type of * mycotoxin * produced by Aspergillus spp.
31
Q

Mycotoxicosis – toxins not pathogens

▪ Group of illnesses and disorders in HB and animals resulting from the ingestion of toxic ? ? (mycotoxins) produced by some fungal species
▪ Therefore, this is NOT a ? driven phenomenon and as such does not involve fungal pathogens such as ? or ? fungi

GO THROUGH THE E.G. meticulously
Examples include:
▪ Claviceps purpurea (rye mold) - contaminated rye produces ? (alkaloid) and leads to ? (convulsive, gangrenous)

▪ Aspergillus (flavus; parasiticus)– produces ** ? **; grows in many plant materials (peanuts, corn, other grains); low levels of toxin can be ? (leads to aflatoxicosis)

▪ ? ? - poisonous mushroom / toadstools (Mycetismus- a fruiting body of fleshy fungi)

A

Mycotoxicosis – toxins not pathogens

▪ Group of illnesses and disorders in HB and animals resulting from the ingestion of toxic secondary metabolite (mycotoxins) produced by some fungal species
▪ Therefore, this is NOT a pathogen driven phenomenon and as such does not involve fungal pathogens such as dermatophyte or dimorphic fungi

GO THROUGH THE E.G. meticulously
Examples include:
▪ Claviceps purpurea (rye mold) - contaminated rye produces ergot (alkaloid) and leads to ergotism (convulsive, gangrenous)

▪ Aspergillus (flavus; parasiticus)– produces ** AFLATOXIN **; grows in many plant materials (peanuts, corn, other grains); low levels of toxin can be carcinogenic (leads to aflatoxicosis)

▪ Amanita phalloides - poisonous mushroom/toadstools (Mycetismus- a fruiting body of fleshy fungi)

32
Q

Aflatoxicosis: ingestion of aflatoxin from fungal contamination of feed

  • Aflatoxins are produced by certain strains of ? on crops like soybeans, corn (maize), and other cereals either in the field or during storage when moisture content and temperatures are sufficiently high for mold growth.
  • Subsequent ingestion of infected feed causes clinical signs of disease (vomiting, hemorrhage, death)
  • ? is the target organ as metabolism of the toxins occurs there.
  • Acute infection may have increased liver ?, to assist in diagnosis (histopath of liver)
  • Control, by avoiding ? feeds, checking quality of feed, storage conditions etc
A

Aflatoxicosis: ingestion of aflatoxin from fungal contamination of feed

  • Aflatoxins are produced by certain strains of Aspergillus on crops like soybeans, corn (maize), and other cereals either in the field or during storage when moisture content and temperatures are sufficiently high for mold growth.
  • Subsequent ingestion of infected feed causes clinical signs of disease (vomiting, hemorrhage, death)
  • Liver is the target organ as metabolism of the toxins occurs there.
  • Acute infection may have increased liver enzymes, to assist in diagnosis (histopath of liver)
  • Control, by avoiding contaminated feeds, checking quality of feed, storage conditions etc
33
Q

Moldy Corn Toxicosis in Horses

Fumonisin toxicity
* Known as equine leukoencephalomalacia or * ? *, more commonly known as “ ? corn poisoning”
* Defined as a mycotoxic disease of the central ? system
* Most ? mycotoxin-related syndrome in horses.
* Toxin produced by fungus ? moniliforme
* Also causes porcine pulmonary edema syndrome in pigs

A

Moldy Corn Toxicosis in Horses

Fumonisin toxicity
* Known as equine leukoencephalomalacia or * ELAM *, more commonly known as “ moldy corn poisoning”
* Defined as a mycotoxic disease of the central nervous system
* Most common mycotoxin-related syndrome in horses.
* Toxin produced by fungus Fusarium moniliforme
* Also causes porcine pulmonary edema syndrome in pigs

34
Q

Laboratory Diagnosis

  • initially basesd on assessment of source (host animal, lesion appearance etc.)
  • in cats and dogs, examination of lesions with a wood’s lamp is helpful
    • Filtered ? light
    • M. ? often will fluoresce green due to a tryptophan metabolite
    • 50-60% of infected animals will be positive
  • skin scraping and hair examination
    • observe for hyphae and arthroconidia
A

Laboratory Diagnosis

  • initially basesd on assessment of source (host animal, lesion appearance etc.)
  • in cats and dogs, examination of lesions with a wood’s lamp is helpful
    • Filtered UV light
    • M. canis often will fluresce green due to a tryptophan metabolite
    • 50-60%
  • skin scraping and hair examination
    • observe for hyphae and arthroconidia
35
Q

Laboratory Diagnosis

  • include material from the ? of any lesion
  • ?% potassium hydroxide and heated gently
    • treatment clears sample and allows
      better microscopic exam (100x)
  • Stains may improve ?
    • permanent ink, lactophenol cotton blue, dimethylsulfoxide
    • ? white reagent imparts fluorescence to fungal structures

(we need something to bind to chitin)

A

Laboratory Diagnosis

  • include material from the margins of any lesion
  • 10-20% potassium hydroxide and heated gently
    • treatment clears sample and allows
      better microscopic exam (100x)
  • Stains may improve visualization
    • permanent ink, lactophenol cotton blue, dimethylsulfoxide
    • Permanent white reagent imparts fluorescence to fungal structures
36
Q

Culture

  • Sabouraud’s destrose (SabDex) agar at 25 degree C for up to 3 weeks
  • ? Test Medium (DTM) +/- Rapid Sporulation Medium
    • phenol red indicator
    • beware of false positives
  • molecular techniques
A

Culture

  • Sabouraud’s destrose (SabDex) agar at 25 degree C for up to 3 weeks
  • Dermatophyte Test Medium (DTM) +/- Rapid Sporulation Medium
    • phenol red indicator
    • beware of false positives

(but you never really know if you’re culturing the primary pathogen because there’s such a differential between the way some fungi grow)

  • molecular techniques
37
Q

(recall: dimorphic fungi not zoonotic, altho humans can catch this infection)

A