Yeast and Dimorphic Fungal Infections (Ex3) Flashcards
1
Q
Candida albicans
- habitat
- what is it?
- infections caused
A
- normal flora of mouth, intestine, and lower urogenital tract of animals and humans
- gram-pos yeast, dimorphic fungus
- Thrush: whitish-yellow hyperkeratotic lesions
- plaques in tongue, mouth, and stomach
- systemic infections: mastitis, vaginitis
- diaper rash
2
Q
Malassezia pachydermatis
- morphology
- habitat
- infection caused
A
- thick walled, bottle shaped yeast
- commensals of skin of animals
- causes otitis externa in dogs
- causes dermatits
3
Q
Morphology and Habitats of Crytpcoccus neoformans and C. gattii
A
- large, round to oval, budding yeast
- prominent capsule in vivo
C. neoformans: pigeon droppings
C. gattii: eucalyptus trees
4
Q
Crytpococcus neoformans
- infections caused
A
- disease of the immunocompromised
- chronic granulomatous infection of upper respiratory tract, CNS, skin, eye, and lymph nodes
- when inhaled, granulomas of nasal sinuses
- gelatinous masses and polyps with numerous organisms and minimal inflammation
- granulomas in immunocompetent animals
5
Q
Describe Thermally Dimorphic fungi
What are the members?
A
- single cell (yeast) or spherule at body temp
- mold forms at ambient room temp
- Histoplasma
- Blastomyces
- Coccidioides
- Sporothrix
6
Q
Blastomyces dermatitidis
- disease caused
- morphology
- route of entry
- hosts
A
- Blastomycosis, disseminated disease common
- dimorphic fungus, large broad-based budding yeast with thick cell wall
- inhalation of spores
- dogs and humans
7
Q
Histoplasma capsulatum
- disease caused
- morphology
- habitat
- transmission
- hosts
A
- histoplasmosis, respiratory or disseminated disease
- small, oval yeast in macrophages
- grows in dark, moist soil, covered with droppings
- route of entry inhalation, dry and dusty conditions, disturbance of soil
- dogs, cats, and humans
8
Q
Coccidioides immitis
- morphology
- disease caused
- transmission
- hosts
A
- no yeast form: large, thick-walled spherules containing endospores
- coccidioidomycosis, chronic/active respiratory and disseminated disease similar to TB, osteomyelitis
- inhalation of arthroconidia, dry conditions and soil disturbances
- humans, dogs, and horses
9
Q
Sporothrix schenkii
- morphology
- habitat
- transmission
- disease caused
A
- cigar shaped, elongated, pleomorphic yeast
- lives in sphagnum moss, hay, and soil
- woody, thorny plants
- entry through puncture wound
- disease usually subcutaneous, skin nodules, and regional lymphatics
10
Q
What is Beta-D glucan assay?
A
- general screening of invasive fungal disease
- false positives and negatives may occur
11
Q
What is Cryptococcus neoformans latex agglutinatin test?
A
- qualitative and semi-quantitative test for detection of capsular polysaccharides antigens of C. neoformans in serum or CSF
- good value
12
Q
What are zygomycets?
A
- saprophytic filamentous fungi
- hyphae are broad, thin-walled, irregular, non-septate, right-angle branching asexual spores
- produced in a sporangium
13
Q
What is hyaline fungus?
A
- saprophytic filamentous fungi
- hyphae are narrow, thick-walled, parallel, septate, acute angle branching asexual spores
- produced on fruiting structures called conidia
- have rapid growth
14
Q
What is phaeoid/dematiaceous fungus?
A
- saprophytic filamentous fungi
- hyphae are narrow, thick-walled, parallel, septate, acute angle branching asexual spores
- contain melaninsome and may produce yeast forms
15
Q
Aspergillus
- type of fungus
- how does it cause infection?
A
- hyaline fungus, so fast growing
- invades damaged tissue along blood vessels
