Mycology Flashcards
Rounded fungi that reproduce by budding
yeast
Parasitic and saprophytic fungi causing cottony growth on an organic substance
Mold
Systemic fungi
Yeast at body temp, Mold at room temp
Dimorphic fungi
Found on humans
Anthropophilic
Parasites of animals
Zoophilic
Free living in soil
Geophilic
Compared to bacteria, fungi needs less ___________ to survive
moisture
Fungus stains what color with Gram stain?
Purple (+)
Extremely pathogenic systemic fungi that grows at 37* C
Yeast
What kind of colonies does yeast grow on agar?
Creamy, pasty colonies
Yeast is __________ than GPCOC
bigger
Most common all purpose fungal media
Sabourad’s Dextrose Agar
Can also be used to grow yeast
Blood agar
It is not possible to ID most yeast by
microscopic examination
Yeast is IDed by using
biochemicals
How long should yeast be incubated?
3-5 days
Yeast that is commonly found in avian excreta, especially pigeon droppings
Can be aerosolized, inhaled, and could be 100% fatal if untreated
Cats are most commonly infected (nasal discharge and unresponsive to abx)
Cryptococcus neoformans
Found in cytoplasm of macrophages
Dimorphic soil fungus and most common in Ohio, Missouri, and Mississippi River Valley
Inhalation of spores is most common route of infex
Bird and bat droppings
Histoplasma capsulatum
Dimorphic soil fungus in semi-arid areas such as California, Nevada, Utah, Arizona, New Mexico, and Texas
Can take weeks to years to develop C/S
Young males more likely to be infected
Coccidioides immitus
Dimorphic fungus
Mycelial phase found in soil and cultures, large thick walled yeast form in tissues
3 clinical forms: primary pulmonary, disseminated dz, and local cutaneous infex
More prevalent in dogs (HUNTING BREEDS) than cats
Blastomyces dermatitidis
Yeast that causes thrush, stomatitis, and pneumonia in birds
Candida albicans
Common yeast in dogs and cats - Otitis externae and dermatitis
Dx made by impression smear
Skin scales and infected hair samples can be mixed with KOH and dissolve debris
Malassezia pachydermatitis
2 types of molds
- Saprophytes
2. Dermatophytes
Type of mold that is free living
Saprophytes
Type of mold that causes skin infections
Ex: ringworm
Dermatophytes
Molds grow _____ hyphae
aerial
How do molds appear on media?
Furry/Fuzzy
Molds produce a fruiting body that produce
spores
Most commonly used media for mold growth
Selective media containing antibiotics to inhibit bacteria and other fungus
Indicator turns red in 72 hrs if contains dermatophyte
DTM (Dermatophyte Test Medium)
AKA Fungassay
Genus of fungi that causes tinea capitis, tinea corpus, ringworm, and other dermatophytes
Microsporum
Genus of pathogenic fungi that causes dermatophytoses in the hair, skin, and nails of humans
Trichophyton
Genus of fungus that causes superficial and cutaneous mycoses
Epidermophyton
2 types of test mediums for mold
- DTM
2. Derm Duet
Mold should be incubated at what temp?
Room temperature
If there is fluffy white to apricot growth on DTM it is
Dermatophyte +, ringworm +
If there is black, brown, dark green growth on DTM it is
Saprophyte +, ringworm -
How should DTM be stored for incubation?
Room temp, loose cap for aerobic growth, and in a dark place
Mold media that is a plate with 2 sides (DTM and Rapid Sporulation Media)
Derm Duet
No matter which product you use, you must examine the specimen under the _____________ to make a proper Dx
microscope
Which slide prep involves using Lactophenyl Cotton Blue stain(LPCB) or NMB and using a pair of flammed teasing needles to pick mold from a plate?
Tease Prep
Which slide prep tends to be gentler and leaves the mold more intact?
Utilizes clear, transparent tape to obtain mold from plate
Scotch Tape Prep
Morphologic feature that is long slender tubes
Hyphae
Which type of hyphae contain walls or divisions
Septate hyphae
AKA conidia
Usually how mold grows
Micro or Macro
Spores
Spores enclosed in sacs and are released from these
Fruiting bodies
Dz caused by dermatophytes is called
Dermatomycosis, cutaneous mycosis, or ringworm
Alopecia in a circular area, hyperkeratosis, and possible redness or brown spots can be seen with
Dermatomycosis
Dermatophyte that fluoresces under UV light
Most common cause of ringworm
ZOONOTIC
Microsporum canis
Dermatophyte that causes ringworm in pigs, cats, horses, cattle, chickens, hedgehogs, guinea pigs, kangaroos, and rabbits
Trichophyton mentagrophytes
Most common dermatophyte in cows
Infects humans but will not fluoresce under black light
Trichophyton verrucossum
Produces macroconidia (giant spores with thick walls) Spindle or boat shaped
Microsporum
Produces microconidia
Small spores that are tear shaped and in grapelike clusters
Slender and elongated
Trichophyton
A saprophyte seen in birds that is a common cause of serious URI
Opportunistic
Aspergillus
