9. Dimorphic Fungi Flashcards
Primary infection of dimorphic fungi
Pulmonary
How are tissue specimens processed?
Minced
How are pleural fluid and CSF specimens processed?
Concentrated
How are mucus and pus specimens processed?
Mucolytic agent
Easiest and quickest method for microscopic examination for dimorphic fungi
KOH preparation (+ Calcofluor)
Stains used for in situ staining
- H&E
- PAS
- GMS
Culture media for primary isolation of dimorphic fungi
SDA
SABHI
BHI
Incubation temp of media for primary isolation of dimorphic fungi
30°C
Media used for subculture for dimorphic fungi
PDA
MOT of dimophic fungi
Respiratory route
Immune response to dimorphic fungi
Cellular immune response
True/False. Dimorphic fungi are not strong antigens.
True
Explain dimorphic fungi antibody detection
Positive: exposure (not necessarily infection)
AIDS patients will be negative
What is detected in the expantigen test for dimorphic fungi?
Cell free extracts of the fungus
Used to react with known antisera in the exoantigen test for dimorphic fungi
Material extracted from mold phase
Causative agent of Gilchrist’s disease
Blastomyces dermatitidis
Disease caused by B. dermatitidis
Blastomycosis/Gilchrist’s disease
2 types Blastomycosis
- chronic cutaneous blastomycosis
- systemic blastomycosis
Most common manifestations of systemic blastomycosis
- bone lesions
- osteomyelitis
After how many days will yeast forms of B. dermatitidis appear on enriched media?
After 10-15 days
Associated with Valley fever
Coccidioides immitis
The most virulent of all agents of human mycoses
Coccidioides immitis
Disease caused by C. immitis
Primary pulmonary coccidiodomycosis
After how many days will C. immitis appear on SDA/SABHI?
3-5 days
Arthroconidia of C. immitis appear on SDA/SABHI after
7-10 days
Has whote and cottony colonies (cobwebs)
C. immitis
Has barrel-shaped arthroconidia
C. immitis
Associated with disjuncture cells
C. immitis
A soil saprobe with high nitrogen content
Histoplasma capsulatum
Associated with Spelunker’s disease
H. capsulatum
Disease caused bu H. capsulatum
Histoplasmosis
Cell where H. capsulatum organisms can be found
Inside macrophages (histiocytes)
After how many days will the yeast form of H. capsulatum appear?
After 10-15 days
Has macroconidia that become tuberculate with age
H. capsulatum
A soil saprobe of acid soil
Paracoccidioides brasiliensis
Disease caused by P. brasiliensis
Paracoccidioidomycosis
Mold colony of P. brasiliensis mature in
2-3 weeks
Has a mariner wheel-shaped yeast form
P. brasiliensis
Associated with Rose gardener disease
Sporothrix schenckii
Disease caused by S. schenckii
Sporotrichosis
Mold form of S. schenckii develops in
3-5 days
Has hyphae frequently found as ropes
S. schenckii
Has conidiophores that produce multiple conidia in flowerets arrangement
S. schenckii
Has a yeast form that is cigar-shaped
S. schenckii
Enumerate the thermal dimorphs
- Blastomyces dermatitidis
- Coccidioides immitis
- Histoplasma capsulatum
- Paracoccidioides brasiliensis
- Sporothrix schenckii
- Penicillium marneffei