Term
Which yeast are germ tube positive? |
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Definition
C. albicans and C. dublinenses |
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Term
Which yeast is germ tube negative? |
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Definition
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Term
Which yeast is India Ink positive? |
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Definition
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Term
What makes C. albicans/dublinenses germ tube positive? |
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Definition
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Term
What makes C. neoformans India Ink positive? |
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Definition
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Term
What differentiates Epidermophyton from the other dermatophytes? |
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Definition
Epidermophyton has thin and smooth macrocondidia growing directly from septate hyphae |
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Term
What differentiates Microsporom from the other dermatophytes? |
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Definition
Microsporum has rough and turbulent macrocondidias with a spindle shape, growing from multiseptate hyphae |
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Term
What differentiates Trichophyton from the other dermatophytes? |
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Definition
Trichtophyton have microcondidia growing directly from the hyphae |
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Term
What differentiates Penicillium from Aspergillus? |
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Definition
Penicillium has a condidiaphore which gives rise to thin finger-like phialides |
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Term
What differentiates Aspergillus from Penicillium? |
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Definition
Aspergillus has condidiaphores which give tise to a vesicle which has phialides on top of it |
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Term
What are the names of the three dimorphic fungi? |
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Definition
Blastomyces dermatitdis, Coccoidiodes immitis, and Sporothrix schenkeii |
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Term
What makes the yeast form of Blastomyces dermatitdis special? |
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Definition
grows at 37 C, large, broad-based, unipolar yeast-like cell |
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Term
What makes the yeast form of Coccoidiodes immitis special? |
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Definition
grows at 37 C, large, thick, contains endospores |
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Term
What makes the yeast form of Sporothrix schenkeii special? |
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Definition
grows at 37 C, oval to cigar shaped yeast cells, single-multiple buds from one cell |
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Term
What makes the mold form of Blastomyces dermatitdis special? |
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Definition
grows at 25 C, septate hyaline hyphae, unbranched, short condidiophores at right angles |
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Term
What makes the mold form of Coccoidiodes immitis special? |
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Definition
grows at 25 C, barrel-like anterospores with thin septate hyphae |
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Term
What makes the mold form of Sporothrix schenkeii special? |
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Definition
grows at 25 C, septate hyaline hyphae, condidiophores and conidia, looks like roses growing off the hyphae |
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Term
Name the dematiacious molds |
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Definition
Alternaria spp. and Curvularia spp. |
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Term
What differentiates Alternaria spp. from Culvularia spp.? |
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Definition
Alternaria spp. appears with transverse and longitidinal sepations in the condidia |
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Term
What differentiates Culvularia spp. from Alternaria spp.? |
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Definition
Culvularia spp. appears with curved macrocondidia |
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Term
What color is a positive modified kinyoun stain? |
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Definition
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Term
What color is a positive kinyoun stain? |
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Definition
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Term
What color is a positive fluorescent stain? |
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Definition
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Term
What color is a negative modified kinyoun stain? |
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Definition
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Term
What color is a negative kinyoun stain? |
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Definition
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Term
What color is a negative fluorescent stain? |
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Definition
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Term
Why do we use Kinyoun stains? |
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Definition
Kinyoun stains are used for bacteria which do not take up the Crystal Violet stain well |
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Term
Why do we use modified kinyoun stains? |
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Definition
some bacteria do not take up the crystal violet well, and do not have enough mycolic acid in their walls to hold the primary stain during decolorization, the decolorizer in modified kinyoun is less potent |
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Term
How do you do a modified kinyoun? |
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Definition
3 minutes with carbol fuchsin
rinse
decolorize with 1% sulfuric acid
rinse
Counter stain for 30 seconds with methylene blue, malachite green or brilliant green
rinse
air dry |
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Term
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Definition
endogenous strain, obligate anaerobe, causes lumpy jaw and IUD infections, sulfur granules present in tissue, molar tooth colony, modified kinyoun negative |
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Term
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Definition
obligate aerobe, causes pulmonary and skin/tissue infections (mycetomas), colonies appear white, tan, orange, dry, wrinkled, and chalky, modified kinyoun positive |
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Term
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Definition
causes skin infections (mycetomas) and pulmonary diseases, colonies appear waxy, modified kinyoun negative |
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Term
How do you do a kinyoun stain? |
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Definition
5 minutes with carbol fuchsin rinse with tap water 2 minutes with 3% decolorizer rinse 1-3 minutes with methylene blue rinse air dry |
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Term
How do you do a fluorescent stain? |
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Definition
15-20 minutes with auramine-rhodamine stain rinse 2-3 minutes with 3% HCl decolorizer rinse 2-4 minutes with potassium permanganate rinse air dry |
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Term
Describe mycobacterium tuberculosis |
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Definition
slow grower, nonpigmented, tan, buff, dry and rough on plate, cord formation on stained smear, niacin positive, fluorescent and kinyoun positive |
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Term
Which mycobacterium are photochromagens |
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Definition
M. kansasii and M. marinum |
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Term
When does a photochromagen produce pigment? |
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Definition
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Term
Which mycobacterium are scotochromagens? |
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Definition
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Term
When does a scotochromagen produce pigment? |
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Definition
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Term
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Definition
rapid grower, buff, moist colonies |
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Term
Describe M. avium-intracellulare |
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Definition
rapid grower, nonphotochromagen |
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Term
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Definition
no growth in routine agar, found on foot pads of armadillos |
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Term
Which other organisms can positive false positives in AFB cultures? |
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Definition
bacteria, nocardia, and yeast |
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Term
What is the general description of mycobacterium? |
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Definition
pleomorphic beaded gram positive rods, non motile, non branching, non spore forming, strict aerobes, varying growth rate, environmental contaminants (except MTB) |
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Term
What are the staining methods for AFB? |
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Definition
Ziehl Nelson, Kinyoun, and Fluorescent |
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Term
What is different between the light microscope and the fluorescent microscope? |
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Definition
Light source comes from above (fluorescent) and below in the light. The fluorescent light hits the molecules and excites them which causes them to give off light as they come back down to ground state |
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Term
What media is mycobacterium cultured on? |
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Definition
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Term
What precautions should you take when working with AFB? |
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Definition
Negative pressure room, biological safety cabinet and face mask, saftey cups for centrifugation, splash-proof discard containers, disposable inoculating needles, disposal of waste |
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Term
What are acceptable specimens for AFB culturing? |
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Definition
respiratory specimens (3 days worth), urine (centrifuge before processing), stools (direct smear screen), bone and tissue (ground up), blood and fluid (mycolyic bottle or isolator tube) |
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Term
What do you use to decontaminate AFB specimens? |
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Definition
1:1 ratio of specimen to NALC with NaOH |
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Term
Describe the steps in processing AFB specimens? |
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Definition
add NALC and NaOH Vortex, let sit for 20 min add phosphate buffer concentrate with centrifugation for 15 min pour off supernatent inoculate media, make 2 smears, heat fix to slide |
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Term
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Definition
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Term
Describe Middlebrook agar? |
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Definition
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Term
In which environment do you incubate LJ slants? |
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Definition
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Term
4 ways of identifying mycobacteria |
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Definition
runyoun classification (growth rate), chromagen (pigment), biochemical testing, or DNA probes/PCR |
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Term
How does Mass Spectrophotmetrey identify mycobacteria? |
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Definition
analysis of proteolytic peptides |
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Term
How does HPLC identidy mycobacteria? |
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Definition
quantification of mycolic acids |
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Term
What are the 5 primary anti-TB drugs? |
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Definition
Isoniazid, Rifampin, Ethambutol, Streptomycin, and Pyrazinamide |
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Term
What are the 3 methods of susceptiblity testing for multi-drug resistant TB |
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Definition
agar with antibiotics, broth dilution (MIC) and PCR |
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Term
What is the general description of Actinomycetes? |
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Definition
beaded, branching, filamentous, gram positive rods |
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Term
5 ways to identify actinomycetes |
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Definition
gram positive rod, branched filaments, grows on BAP, CAP, LJ and SAB (3-6 days), decomposition of casein and DNA sequencing |
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Term
Yeast on a gram stain are |
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Definition
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Term
What is KOH prep used for? |
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Definition
breaks down keratin and releases it into solution |
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Term
How do you identify C. neoformans? |
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Definition
india ink positive, urease positive on urea slant or rapid latex antigen test on CSF or serum |
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Term
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Definition
long structures, intertwined on SAB agar, characteristic of fungal cultures |
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Term
How do you identify C. glabrata? |
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Definition
RAT test positive (rapid assimilation trehelose) |
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Term
How do you identify yeast? |
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Definition
Rapid ID or automated ID based on sugar assimilation |
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Term
How do you identify mold? |
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Definition
Structures and touch prep |
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Term
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Definition
lactophenol cotton blue stain |
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Term
how do perform a slide culture? |
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Definition
Take a circle of sab dex agar set on glass side in petri dish (with toothpicks and moist towel) inoculate agar with mold via notches on side corners place cover slip on top incubate remove cover slip, stain and look for structures |
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Term
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Definition
peptide nucleic acid FISH, tag and attach probe to molecular structure |
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Term
What is unique about the structure of C. albicans? |
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Definition
chlamydospores and psuedohyphae |
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Term
How do you differentiate between Geotrichum spp. and trichosporon spp? |
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Definition
Geotrichum shows individual artherospores with septate hyphae, Trichosporon shows blastocondidia |
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Term
What are the three Zygomycetes? |
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Definition
Rhizopus, Mucor and Absidia |
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Term
What is characteristic of Rhizopus? |
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Definition
rhizoids at the bottom of sporeangiophores |
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Term
What is characteristic of Mucor? |
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Definition
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Term
What is characteristic of Absidia? |
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Definition
Rhizoids in between sporeangiophores |
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Term
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Definition
Cryptococcus neoformans, india ink |
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Term
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Definition
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Term
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Definition
Geotrichum spp. Touch Prep |
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Term
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Definition
Trichosporon sp. Touch prep |
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Term
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Definition
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Term
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Definition
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Definition
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Definition
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Definition
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Definition
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Definition
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Term
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Definition
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Term
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Definition
Blastomyces dermatitidis, yeast |
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Term
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Definition
Blastomyces dermatitidis, mold |
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Term
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Definition
Sporothrix schenkeii - mold |
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Definition
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Definition
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