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Opportunistic fungi
Phaeohyphomycosis, Hyalohyphomycosis, & Zygomycosis
Question | Answer |
---|---|
Name the 4 Aspergillus organisms. | A. fumigatus A. flavus A. niger A. terreus |
What is the difference between uniseriate and biseriate fungi? | Uniseriate - phialides are directly attached to the vescicle Biseriate - Phialides are attached to the metula which sit on the phialides |
What is the general growth rate of Aspergillus species? | Rapid - 7 days |
Describe the hyphae of Aspergillus. | Septate and hyaline |
Which Aspergillus species has a blue to green suede colony and is the most important pathogen in the Aspergillus family? Where does this organism come from? | A. fumigatus - found in soil and dust. Usually associated with construction. |
Describe the microscopic appearance of A. fumigatus. | Uniceriate Columnar conidia covering top of vesicle Smooth conidiophore |
What is the second most common Aspergillus species? What is the colony's appearance of the organism? | A. flavus - lime green colony |
This Aspergillus species has a rough conidiophore, is biseriate, completely covered vesicle, and lime-green conidia. | A. flavus |
Which Aspergillus species has a salt & pepper colony appearance? | A. niger |
What is the microscopic appearance of A. niger? | Smooth hyaline conidiophore Biseriate with entire covering of vesicle Dark conidia Sometimes dark metula |
Which Aspergillus species is most commonly associated with ear infections? | A. niger |
This Aspergillus species is resistant to normal treatment for fungus like Amphitoceran B. | A. terreus |
What is does the colony of A. terreus look like? | Tan,cinnamon-colored appearance |
This Aspergillus species microscopically has smooth conidiophores, is biseriate with multiple phialides on each metula, and slightly yellow conidia. | A. terreus |
What is the route of transmission for Aspergillus species? | Airborne transmission usually associated with construction or renovations |
How do Aspergillus species cause disease? | Conidia invade pulmonary cavities to become invasive. Granulocytopenia is the biggest risk for invasive disease especially in bone marrow patients. |
What are 3 clinical manifestations in the form of hypersensitivity lung disease? | 1. Asthma 2. Alveolitis "farmers' lung" 3. Bronchopulmonary Aspergillosis |
What are other clinical manifestations that may occur from Aspergillus species? | 1. Mycetomata "fungus balls" 2. Dissemination to CNS and organ systems 3. Eye infection secondary to trauma 4. Ear infection 5. Sinus infection 6. Osteomyelitis |
Which opportunistic fungi is a common contaminant? | Penicillium |
Penicillium commonly causes which 2 diseases? | Keratitis and endocarditis |
What are the general characteristics of a Penicillium colony? | Fast growing Shades of green |
Describe the microscopic appearance of Penicillium. | Conidiophore are rough or smooth Phialides are slightly elongated Conidia are variable: Round to eliptical Smooth to rough May have greenish-blue coloring or may be hyaline |
True or False: Paecilomyces lilacinus causes problems in healthy individuals. | False - this can easily cause deadly diseases in immunocompromised patients. |
This organism is resistant to nearly everything except ketoconizole. | Paecilomyces lilacinus |
This is a non-dermatophyte that may cause nail diseases. | Paecilomyces lilacinus |
What are 3 complications associated with Paecilomyces lilacinus? | 1. Keratitis 2. Endocarditis 3. Sinusitis |
Is Paecilomyces lilacinus a fast or slow growing fungus? | Fast |
What organism has phialides with tapered or a long neck appearance, long chains of oval conidia, with some rough walled conidiophores? | Paecilomyces lilacinus |
Keratitis, osteomyelitis, and infections in bone marrow transplansts are complications caused by what fungus? | Fusarium |
Describe the colony characteristics of Fusarium. | Fast growing pale or brightly colored cottony colony. |
Which organism has macroconidia with a green bean appearance? What do the microconidia of this organism look like? | Fusarium. Microconidia are short with 2-3 cells. |
In what culture do we usually find Fusarium species? | Blood culture |
People who wear extended wear contacts may be at higher risk of this fungus. | Fusarium |
Which organism appears as a yeast but has no true yeast form? | Fusarium |
This disease is caused by inhalation of the organism. Dissemination occurs rapidly to eyes and sinuses and skin lesions form all over the body. | Fusariosis |
True or False: Pythiosis occurs only in humans. | False - this is commonly found in animals that graze in swamp lands |
Where is Pythium insidiosum found and how does it gain access to the body? | Stagnant water, gaining access through the sinuses |
General characteristics of this group of organisms includes: Sparsely septate ribbon like hyphae, rhizoids, and sporangiophores. | Zygomycetes |
What to Zygomycete colonies look like? | Rapid growing Lid-Lifters Cotton-candy like White to grey coloration |
What population is most supsceptible to Zygomycete infections? | Diabetics - particularly those in ketoacidosis or those who do not manage their insulin levels |
This organism can grow within 24 hours and likes higher temps affecting the brain. | Zygomycete species. |