MICR5829 L3: Mycology 3/1/25

What is this?

-Eukaryotic, nonvascular, produces exoenzymes

-Spores/vegetative reproduction

Fungi

What do fungi produce?

Hint: Kai comes from this group

Exoenzymes

True or False: Fungi can produce sexual or asexual spores

True

True or False: Medically important fungi are typically motile

False, they are typically non-motile

What is this?

-Fungi with unicellular vegetative body

-Example: Candida albicans

Yeast

What is this?

-Fungi with multicellular vegetative body

-Example: Scedosporium apiospermum

Molds

What is this?

-Molds

-Fungi with multicellular vegetative body

-Example: Scedosporium apiospermum

What is this?

-Microscopic threads found inside multicellular fungi

Hyphae

What is this?

-Hyphae

Microscopic threads found inside multicellular fungi

What is this?

-Internal divisions found inside hyphae and various sporing structures

Septa

What is this?

-Septa

Internal divisions found inside hyphae and various sporing structures

What is this?

-Mass of hyphae found inside fungi

-Hidden from view, growing inside food source

Mycelium

What is this?

-Mycelium

-Mass of hyphae found inside fungi

-Hidden from view, growing inside food source

What is this?

-Food source used to hide mycelium from view

Rotting wood

What is this?

-Visible part of fungi, mushroom attached to mycelium

-Example: Amanita muscaria

Fruiting body

What is this?

-Fruiting body

-Visible part of fungi, mushroom attached to mycelium

-Example: Amanita muscaria

What is this?

-Feeds on preformed organic material

Heterotrophic

What is this?

-Plans that manufacture their own energy requirements via photosynthesis

Autotrophic

True or False: Fungi digest before ingesting, unlike animals which ingest before digesting

True

True or False: Fungi store food as starch, and animals store food as glycogen

False, only plants store food as starch. Both fungi and animals store it as glycogen

What role does fungi play in the nitrogen/carbon cycle?

Breaking down organic material

What are some possible host-fungal interactions in an ecosystem?

-Saprophytes

-Symbionts

-Parasites

How does a potential host makes contact with fungi?

-Inhale, contact

-Implant, accidentally ingest

What are some environments that could potentially contain fungi?

-Soil/water

-Plant material

-Guano

-Animal/human (some dermatophytes)

What happens if a host contracts disease from a fungi?

-Toxicity

-Allergy

-Infection (mycoses)

What happens if a host does not contract disease from a fungi?

-Contamination

-Colonization

-Dormancy

Name the 4 types of Mycoses

1) Superficial/Cutaneous

2) Subcutaneous

3) Endemic

4) Opportunistic

What is this?

-Dermatophytoses (Tinea, ringworm)

-Superficial candidiasis

-Pitryiasis Versicolor

-Piedra

-Erthyasma

-Trichomycosis Axillaris

Superficial/Cutaneous Mycoses

What is this?

-Includes dermatophytes

-Uses keratin as a substrate

-Can affect any superficial body site

Superficial/Cutaneous Mycoses

What do superficial/cutaneous mycoses use as a substrate?

Keratin

True or False: Superficial/cutaneous mycoses can affect any superficial body site

True

What is this?

Superficial/Cutaneous Mycoses

-Dermatophytoses (Tinea, ringworm)

-Superficial candidiasis

-Pitryiasis Versicolor

-Piedra

-Erthyasma

-Trichomycosis Axillaris

What are some Dermatophytes associated with Superficial Mycoses?

-Trichophyton

-Microsporum

-Nannizia

-Epidermophyton

What type of dermatophyte/superficial mycoses is this?

-Only infect men

Anthropophilic

What type of dermatophyte/superficial mycoses is this?

-Animal reservoir of infection

Zoophilic

What type of dermatophyte/superficial mycoses is this?

-Found in the soil

Geophilic

What type of dermatophytes/superficial cutaneous mycoses are these?

-Trichophyton rubrum

-Trichophytum interdigitale

-Trichophyton tonsurans

-Epidermophyton floccosum

-Trichophyton violaceum

-Trichophyton soudanese

-Microsporum audouinii

Anthropophilic

Which anthropophilic dermatophytes/superficial mycoses infect refugees?

-Trichophyton violaceum

-Trichophyton soudanese

-Microsporum audouinii

Who do these anthropophilic/superficial mycoses tend to infect?

-Trichophyton violaceum

-Trichophyton soudanese

-Microsporum audouinii

Refugees

What type of dermatophytes/superficial cutaneous mycoses are these?

-Microsporum canis

-Trichophyton mentagrophytes

-Trichophyton verrucosum

Zoophilic

Who do these anthropophilic/superficial mycoses tend to infect?

-Microsporum canis

Dogs

Who do these anthropophilic/superficial mycoses tend to infect?

-Trichophyton metagrophytes

Rodents, animals

Who do these anthropophilic/superficial mycoses tend to infect?

-Trichophyton verrucosum

Cattle

What type of dermatophytes/superficial cutaneous mycoses are these?

-Nannizia gypsea

-Microsporum gypseum

Geophilic

Where are these dermatophytes/superficial mycoses found?

-Nannizia gypsea

-Microsporum gypseum

Soil

What is this?

-Fungus gains entry to tissue

-Usually by penetrating injury

Subcutaneous Mycoses

What is this?

-Subcutaneous Mycoses

-Fungus gains entry to tissue

-Usually by penetrating injury

What is this?

-Sporotrichosis

-Chromoblastomycosis

-Phaeohyphomycosis

-Mycotic mycetoma

-Zygomycosis

-Lobomycosis

-Rhinosporidiosis

Subcutaneous Mycoses

What subcutaneous mycoses is this?

-Handling moldy hay/organic material

-Wheat growing areas, hay mulch

Sporotrichosis

What allows sporotrichosis to spread lymphatically despite its normal environmental form?

Thermally dimorphic

What does it mean for subcutaneous mycoses Sporothrix schenkii to be thermally dimorphic?

-Spores/conidia at 26C

-Forms yeast at 37C

What form does subcutaneous mycoses Sporothrix schenkii have at 26C?

-Spores (conidia) on fine denticles

-Flowerlike, tapered conidiophore

What form does subcutaneous mycoses Sporothrix schenkii have at 37C?

Cream-colored moist, smooth yeast colonies

What is this?

-Thermally dimorphic fungi

-Yeast at body temp, mold in environment

-Healthy individuals are infected (RG3 pathogens)

-Known geographic distribution

Endemic Mycoses

What is this?

-Endemic Mycoses

-Thermally dimorphic fungi

-Yeast at body temp, mold in environment

-Healthy individuals are infected (RG3 pathogens)

-Known geographic distribution

How are endemic mycoses contracted?

Inhalation -> pulmonary infection -> dissemination

True or False: Only unhealthy individuals can contract endemic mycoses

False, healthy individuals are infected

What risk group do endemic mycoses belong to?

RG3

What mycoses belong to Risk Group 3?

Endemic Mycoses

True or False: There is no evidence of endemic mycoses transmission among humans or animals

True

What form would an endemic mycoses have at body temperature?

Yeast-like spherule

What form would an endemic mycoses have in the environment?

Mold

True or False: There is a known geographic distribution for each endemic mycoses

True

True or False: In WA, there are rare isolates of endemic mycoses from travellers

True

What is this?

-Coccidioidomycosis

-Histoplasmosis

-Blastomycosis

-Paracoccidioidomycosis

-Talaromyces marneffei

Endemic Mycoses

What are some examples of these?

-Endemic Mycoses

-Coccidioidomycosis

-Histoplasmosis

-Blastomycosis

-Paracoccidioidomycosis

-Talaromyces marneffei

Name a specific agent that causes endemic mycoses

Talaromyces marneffei

What is this?

-Candidiasis

-Cryptococcosis

-Aspergillosis

-Scedosporiosis, Pseudallescheriasis

-Zygomycosis

-Hyalohyphomycosis

-Phaeohyphomycosis

Opportunistic Mycoses

What is this?

-Opportunistic Mycoses

-Candidiasis

-Cryptococcosis

-Aspergillosis

-Scedosporiosis, Pseudallescheriasis

-Zygomycosis

-Hyalohyphomycosis

-Phaeohyphomycosis

What is this?

-Saprophytes, normal flora

-Caused by decreased immune function, allergy, antibiotics, chemotherapy, transplanatation, catheters

Opportunistic Mycoses

What environmental factors cause opportunistic mycoses?

-Saprophytes in nature

-Normal flora

What are some medical reasons that could leave someone vulnerable to opportunistic mycoses?

-Broad spectrum antibiotics

-Catheters/dialysis

-Chemotherapy, immunosuppressive transplant

-Allergy, immunocompromise

What are some clinical laboratory techniques for detecting mycoses infection?

-Direct microscopy

-Culture

-Fungal susceptibility testing

-Basic morphological identification

What clinical laboratory technique is this?

-Wet mount

-10% KOH + Calcofluor White (CW)

-Fluorescent brightener

-India ink for encapsulated yeasts

Direct microscopy

What would you use as a fluorescent brightener for a direct microscopy wet mount?

10% KOH and CW (Calcofluor White)

What would you use to find encapsulated yeasts in a wet mount?

India Ink

What would you use to stain histopathology specimens after air drying a smear for direct microscopy?

-Periodic acid Schiff

-Gomori methanamine silver

What clinical laboratory technique is this?

-Sabouraud Dextrose Agar + chloramphenicol

-SDA + chloramphenicol + cycloheximide

-Brain infusion + 5% sheep blood + chloramphenicol

Clinical isolation media

What temperature would you incubate clinical isolation media at?

26C, 30C, 35C

What anti-fungal is added to SDA + chloramphenicol during clinical isolation media?

Cyclohemixide

What medium is used for clinical isolation?

SDA (Sabouraud Dextrose Agar)

What are these media used for?

-PDA, PCA, MBLA

-Czapek-Dox Agar

-Rice grain, tap water

Inducing mold sporulation

What media is used on dermatophytes to induce mold sporulation?

MBLA (Modified Borelli's Lactrimel Agar)

What media is used on Aspergillus and Penicillium to induce mold sporulation?

Czapek-Dox Agar

What other ingredients are used to induce mold sporulation besides media such as PDA, PCA and MBLA?

-Rice grain

-Tap water

What is this?

-Budding cells abundant

-Colonies white, pink or black

Yeast

What is this?

-Hyphae sparsely or regularly septate

-NO Fruiting bodies (or fruiting bodies with loose conidia)

-Many able to fill a petri dish in a few days

Molds

What type of mold is this?

-Hyphae regularly septate

-No fruiting bodies

Hyphomycetes

What type of mold is this?

-Hyphae regularly septate

-Fruiting bodies loose conidia

Coelomycetes

What type of mold is this?

-Hyphae sparsely septate

Zygomycetes

What are these species?

-Hyphomycetes

-Coelomycetes

-Zygomycetes

Molds

What is this?

-Mostly unicellular

-Pasty oval to round colonies

-Reproduces by budding

Yeast

What is this?

-Yeast

-Mostly unicellular

-Pasty oval to round colonies

-Reproduces by budding

True or False: Yeast is multicellular

False, Yeast is unicellular you *******

How do yeast reproduce?

Budding

What do yeast form when they reproduce by budding?

-Blastospore

-Pseudohyphae

What is this?

-Phenotypically identified with germ tube, chromogenic agars, Pseudohyphae, assimilation/fermentation tests

Yeast

How is yeast phenotypically identified?

-Chromogenic agars

-Germ tube

-Pseudohyphae

-Assimilation/fermentation tests

How are assimilation/fermentation tests useful for phenotypically identifying yeast?

Shows ability to utilize various substrates

What phenotypic identification test is this?

-Selective isolation/presumptive identification

-Direct culture oropharyngeal, genital swabs

-48 hour incubation

-Distinguish mixed cultures

Chromogenic agar