Lab Exam 1 Flashcards
What part of the body does tinea ungium affect?
nails
What part of the body does tinea corprus affect?
body
What part of the body does tinea pedis affect?
foot
What part of the body does tinea barbay affect?
beard
What part of the body does tinea cruris affect?
groin
What part of the body does tinea capitis affect?
scalp
What does the word “tinea” mean?
ringworm
What is the short lateral structure that will develop when certain yeast are incubated at 37C in a rich medium?
germ tube
What is one yeast that is germ tube positive?
Candida albicans
At what temperature should chlamydospore agar be incubated?
25C or room temperature
Where should the technologist look for spores on a chlamydospore agar plate?
on the edge of the cover slip
What color and shape are the spores on a chlamydospore agar plate?
blue and round
What is the principle of the India ink preparation?
India ink particles bounce off the capsule so that you can see a clear halo of the organism under high power
What organism is India ink especially used for?
Cryptococcus neoformans
What type of specimen is most frequently used in an India ink prep?
spinal fluid
What reagent should be used for the examination of the reproductive structures of molds that are already growing in a culture?
lactophenol cotton blue
What technique can be used to “save” wet preps for future use?
clear fingernail polish around the edge of the coverslip to keep it moist
Name several media used for the primary isolation of fungi.
Sabs, SabsC, BHI, SDA, mycosel, mycobiotic
Why would you incubate a culture for fungi at 25 and 37?
fungus is dimorphic; grows as a mold at 25C and a yeast at 37C
What term is used for fungi that grow differently at 25 and 37?
dimorphic or diphasic
Why do mycologists use KOH?
used on a specimen directly from the body because it will dissolve the keratin material of the skin, hair, or nails
What specific protein does KOH affect?
keratin
Name some fungal elements that could be seen in a KOH prep.
hyphae, pseudohyphae, blastospres, arthrospores, budding yeast
What does ectothrix hair invasion mean?
invasion outside of the hair shaft
What does endothrix hair invasion mean?
invasion inside the hair shaft
Name some genus of fungus which cause ringworm.
Microsporum, Epidermophyton, and Trichophyton
Name some genus of fungus which exhibit dimorphism
Blastomyces, Coccidioides, Histoplasma, Sporothrix, and Paracoccidioides
Name some genus of fungus that is a frequent contaminant.
Aspergillus and Penicillium
What is a slide culture?
piece of agar is inoculated on four corners then a coverslip is placed on it and incubated.
What is the best way to observe fungal cultures in their natural morphology?
slide culture
Mucor
Penicillium
Cladosporium
Aspergillus
Microsporum
Trichophyton
