Hyaline Opportunists Flashcards
Natural habitat for hyaline opportunists
Nature
Which type of patient is typically infected w/ hyaline opportunists?
Immunocompromised
Mode of transmission for most fungal infections
- Most often inhaled
- Ingestion or direct inoculation is less common
Four conditions (defects in immune system) that commonly predispose individuals to opportunistic fungal infections
- Diabetes
- Granulocytopenia
- Absence of cellular immunity
- AIDS
Most common patient population that acquires mucormycoses
Type I diabetics (poorly controlled or in ketoacidosis)
What is the name for aseptate, hyaline fungi?
Mucorales (formerly Zygomycetes)
List the four organisms that are agents of mucormycoses
- Rhizopus
- Mucor
- Rhizomucor
- Lichtheimia (formerly Absidia)
Most common agent of mucormycoses and is difficult to treat?
Rhizopus
Mucorales
- Most common route of infection
Inhalation
Mucorales
- More common clinical presentations observed in patients
- Rhinocerebral → nasal sinus infection that spreads to orbits or the brain
- Pulmonary and systemic infections (esp. in BM transplant patients)
- Predilection for invading blood vessels (infarctions)
Mucor
- Microscopic morphology
NO RHIZOIDS`
Rhizopus
- Microscopic morphology
- Usually unbranched sporangiophores
- Distinct rhizoids at base of sporangiophore (collapsed umbrellas)
Rhizomucor
- Microscopic morphology
- Usually branched sporangiophores
- Rhizoids
Lichtheimia
- Microscopic morphology
- Usually branched sporangiophores
- Delicate (and often difficult to find) rhizoids appear at points BETWEEN sporangiophores (internodal)
What is the name for septate, hyaline fungi?
?
Aspergillus fumigatus
- Colony morphology
Blue-gray/blue-greenish colonies
Aspergillus fumigatus
- Microscopic morphology
- Conidia cover only 1/2 of the vesicle
- Uniserate (one row of phialides)
Aspergillus flavus
- Colony morphology
Yellow/brown colonies
Aspergillus flavus
- Microscopic morphology
- Conidia cover most of the vesicle
- Biserate or uniserate
- Rough (spiny) conidiophores
Aspergillus terreus
- Colony morphology
Cinnamon-colored colonies
Aspergillus terreus
- Microscopic morphology
Biserate phialides covering upper half of vesicle
Aspergillus niger
- Colony morphology
Black dots on white
Aspergillus niger
- Microscopic morphology
Biserate phialides covering the entire vesicle
Penicillium
- Colony morphology
Greenish or yellow-green colonies
Penicillium
- Microscopic morphology
- Brush-like appearance of phialides (no vesicle)
- Round conidia in chains
Paecilomyces
- Colony morphology
Colonies are often light pastel colors
Paecilomyces
- Microscopic morphology
- Long, tapered phialides
- Oval conidia
Scopularioposis
- Colony morphology
Buff to brown colonies
Scopularioposis
- Microscopic morphology
Conidia represent a long “string of light bulbs”
Acremonium
- Colony morphology
Fuzzy
Acremonium
- Microscopic morphology
Oval conidia in clusters
Sepedonium
- Microscopic morphology
- Macroconidia resembles Histoplasma capsulatum
- Cigar-shaped macroconidia
Pseudallescheria boydii/Scedosporium boydii
- Microscopic morphology
Single conidia on ends of conidiophores (“lollipop”)
Fusarium
- Colony morphology
Lavendar to rose-colored clonies
Fusarium
- Microscopic morphology
Sickle-shaped macroconidia
Sepedonium macroconidia resembles Histoplasma. How do they differ based on pathogenicity?
- Histoplasma is pathogenic
- Sepedonium is non-pathogenic
Aspergillus
- Clinical presentations
- NEUTROPENIA!!!!
- Allergic aspergillus
- Fungus ball
- Disseminated aspergillosis
This is an overgrowth in an old TB or Histoplasma cavity; noninvasive; tangled masses of septate hyphae are present
Fungus ball
How does Aspergillus become disseminated?
- It produces elastase allowing it to invade and destroy blood vessels
- Surrounding tissue undergoes infarction
Fusarium
- Clinical presentation
Keratitis
Aspergillus spp
- How is it acquire?
Inhalation
Fusarium
- How is it acquired?
Found in ReNu contact solution
