Opportunistic Flashcards
Where is candida albicans normally found?
Skin, mouth, and GI tract. NEVER should be in blood!
What does candida albicans look like histologically?
pseudohypahe and budding yeasts at 20degrees, germ tubes at 37
What disease manifestations can candida albicans cause?
- Oral/esophageal thrush in immunocompromised (neonates, steroids, DM, AIDS)
- Vulvovaginitis (DM, abx use)
- Diaper rash, rash in skin folds of obese individuals
- Disseminated disease, endocarditis in IV drug users
What is the treatment for vaginal candidiasis?
Topical -azole
What is the treatment for oral/esophageal candidiasis?
Nystatin swish&swallow, fluconazole or caspofungin
What is the treatment for systemic candidiasis?
Fluconazole, caspofungin, or amphotericin B.
Where is aspergillus normally found?
Everywhere, frequent lab contaminant.
What does aspergillus look like histologically?
1) Branching septated hyphae - acute angles, 45 degrees.
2) Conidiophore w/ radiating chains: broom-like
What disease manifestations does aspergillus cause?
- Allergic bronchopulmonary pneumonia - IgE mediated, associated with cystic fibrosis and asthma. May cause bronchiectasis and EOSinophilia.
- Aspergilloma = fungas ball in lung cavity, esp after TB infxn
- Aspergillus flavus can produce aflatoxins, associated with hepatocellular carcinoma
- Invasive aspergillus (hematogenous spread) can cause necrotizing pneumonia and disseminate to other organs.
In what patient population is invasive aspergillus more common?
immunocompromised and those with CGD.
How is allergic bronchopulmonary aspergillosus treated?
Corticosteroids
How is aspergilloma treated?
Removal via surg
How is invasive aspergillosis treated?
treat w/ voriconazole, amphotericin B or caspo.
Where is cryptococcus neoformans found?
Pigeon droppings, soil, respiratory transmission
What does cryptococcus look like histologically?
Heavily encapsulated (polysaccharide) yeast. Not dimorphic! Culture on Sabourad agar, stain w/ India Ink and is mucicarmine.