ASPERGILLUS (SYSTEMIC MYCOSES) Flashcards
Describe aspergillus.
Ubiquitous saprophytic molds with opportunistic pathogenic patterns
What is the pathogenic specie of Aspergillus?
A. fumigatus
What is the morphology of Aspergillus spp.?
Fungi with swollen expansion at the tips of aerial hyphae
Aspergillus grows at what temp. ?
40 - 50 C
What are the reservoirs for Aspergillus?
- Soil
- Vegetation
- Feed
- Air
- Water
What are the transmission routes of Aspergillus spp.?
- Inhalation/ingestion
- Intramammary inoculation
- Intrauterine infection
What is the disease induced by Aspergillus fumigatus in poultry?
- Aspergillosis - disease of respiratory system characterized by granulomatous lesions or plaques
- Brooder pneumonia
- Encephalitic aspergillosis (in young poults)
Aspergillus can invade the eggs. True or False?
True
What are the diseases induced by Aspergillus fumigatum in bovine?
- Mycotic abortions in mammals in late pregnancy
- Note: A related fungus (Mortierra wolfi) is responsible for mycotic placentitis
What are the diseases induced by Aspergillus fumigatum in canine?
- Dog aspergillosis - infects nasal passages and paranasal sinuses (common in German shepherd)
What are the postmortem findings in animals infected by A. fumigatum?
- Presence of bright, greenish yellow caseous exudates in the lungs and air sacs
With characteristic inflammatory nodules referred to as “button ulcers”
What are the diseases induced by Aspergillus fumigatum in calves, foals, and cats?
- Intestinal aspergillosis - induces diarrhea
What are the diseases induced by Aspergillus fumigatum in horses?
- Keratomycosis - corneal infection
What are the virulence factors of Aspergillus spp.?
- Endotoxins
- Elastase
- Hemolysins
- Proteolytic enzymes
- Galactomannan (stimulates immediate and delayed type of hypersensitivity
- Polysaccharides
- Lipids (induce monocytosis and tubercle formation)
- Nephrotoxin
- Dermonecrotic toxins
- Aspergillin O (fibrinolytic and anticoagulant properties)
- Henrici’s cell sap toxin with (precipitin and antihemolysin reactions)
- Allergenic factors
What are the diagnostic methods for Aspergillus spp.?
Sample from tissue exudates
What is the preferred culture media and substrates for Aspergillus spp.?
- SDA
- PDA
How do you ID Aspergillus spp.?
- Direct microscopic exam using scrapings from air passages of birds at necropsy
- Cultivation in SDA
- Use of skin test antigens
What are the treatment agents for Aspergillus infections?
- Amphotericin B
- Ketaconazole
How do you control and prevent infection against Aspergillus?
Avoidance of massive exposure
