Flashcards in Yeast-like Fungi Deck (22)
Describe the Germ Tube Test.
2-3 hour incubation in rabbit plasma
What does a germ tube look like and indicate?
No constriction at base the germ tube and positive indicates Candida albicans and Candida dubliniensis
Fermentation is _______ and requires gas production. Tubes must be acidic (yellow) AND produce gas to be considered positive.
What must be done to CHO tubes when testing for fermentation?
Tubes contain Durham tubes and must be oiled before incubating
Assimilation is ________ and commercial system used is the API 20C. CHO is used as a sole carbon source.
What four yeasts do NOT have pseudohyphae on cornmeal?
Cryptococcus, Candida glabrata, Rhodotorula, and Saccharomyces
This is the #1 cause of yeast infections.
This yeast is germ tube positive and has chlamydoconidia on cornmeal.
This yeast has pseudohyphae on cornmeal and has a starburst appearance on the colony
This yeast has dry colonies and show elongated blastoconidia (logs in the stream) on cornmeal agar.
This yeast shows pseudohyphae on cornmeal and have a tangled, crooked appearance.
This yeast is common in diabetic urinary infections; often aggressive and difficult to treat due to resistance; no pseudohyphae; Trehalose positive.
This yeast is common in pulmonary and CNS infections (meningitis); associated with soil contaminated with pigeon, turkey, or chicken droppings (inhalation)
What is a major pathogen in AIDS patients (CNS)?
Describe the appearance of Cryptococcus.
Thick mucopolysaccharide capsule gives the appearance of mucoid colonies; yeast cells appear larger and irregularly sized
What is used to detect cryptococcus?
Antigen detection (more sensitive than India Ink); urease positive; melanin positive (brown on birdseed); no pseudohyphae
Saccharomyces is ascospore _________. pos or neg?
This yeast requires fatty acids (virgin olive oil) for growth; looks like spaghetti and meatballs; associated with systemic infections such as hyperalimentation (patients getting nutrients containing high amount of lipids)
What two yeasts are arthroconidia?
Trichosporon (white piedra) and Geotrichum
These colonies have a red or orange/red pigmentation and are seen where fluids are present or in moist environments.
What kind of reaction are you looking for on an API strip?
Cloudiness or turbidity