A disease caused by fungi; a fungal infection in or on a part of the body.
Mycosis
A kingdom of plantlike spore-forming organisms that grow in masses with out roots, stems, leaves, or photosynthetic pigments.
Fungi
A closed sac-like structure where sporangiospores are formed. (Large sac-like structure).
Sporangium
A single celled or multicellular organism whose cells contain a distinct membrane-bound nucleus.
Eukaryotic
A spore formed by budding, as in yeasts; thin-walled and water-balloon-like.
blastoconidia/blastospores
a spore formed by the rounding-up of a cell; thick walled; intercalary or terminal postion; it is not shed.
chlamydoconidia/chlamydospore
an organism that cannot synthesize its own food and is dependent on complex organic substances for nutition.
hetrotrophic
A plant that derives its nourishment from dead or decaying organic matter.
saprophytic
hyphae that are subdivided into individual cells by transverse walls.
septate
those without walls.
aseptate
basic structural unit of mold, tube like projections.
hyphae
elongated buds that have failed to separate and are connected together to form a link-of-sausage appearance.
pseudohyphae
loose network of hyphae.
mycelium
what are the two types of mycelium?
vegetative
aerial
This type of mycelium is the nutrients absorbing and water exchanging portion.
vegetative
This type of mycelium extends above the substrate.
aerial
Unicellular fungus that reproduce by budding.
yeast
What is the size of yeast?
2.5 to 6 mircrons
what CDC biosafety levels should be used when handling fungi?
II
III
What class of saftey cabinet should be used when handling fungi?
2 or 3
These are single cell forms of fungi.
yeast
These are multiple cells of fungi that form filaments.
molds
true or false
Fungi lack chlorophyll.
true
These are hetrotrophic, saprophytic and/or parasitic organisms that reproduce by spores, either sexually or asexually.
fungi
Tubular filaments or threads that are branched or unbranched.
hypha/hyphae
this is a mass of hyphae.
mycelium
these mycelium project above the substrate and may be comprised of or support elaborate spore bearing, fruiting bodies.
Aerial or reproductive mycelium
True hyphae are filamentous, flat-ended cells that form __________ cells, do not show points of constriction.
transitional
Pseudohyphae have regular points of _________ (link sausages)
constriction
Pseudohyphae are produced in nutritionally _____ environments.
poor
Pseudohyphae may bud to form _________ (yeast cells) with lesser diameter than true hyphae.
blastospores
What are the three types of clinically significant hyphae, and their characteristics?
coenocytic: sparsely septate
pigmented/dark: septate of the dematiceous fungi
Septate: non pigmented hyphae of the hyaline molds
These fungi are cottony, wooly, powdery, or fluffy and have an optimum temperature of 25-30oC.
molds
These fungi are smooth, pasty, mucoid, and butyraceous, they have an optimum temperature of 35-37oC.
yeasts
these fungi possess both mold and yeast phases.
dimorphic fungi
What are the six medically important dimorphic fungi?
H. capsulatum
B. dermatidis
P. marneffei
C. immitis
P. brasiliensis
S. schenkii
Which medically important dimorphic fungi is thermally dimorphic?
C. immitis
Dimorphic fungi in this phase produce delicate hyphae, <1-2 mm, this form of colonies have cobwebs or hair like appearance.
mold/mycelial/saprophytic phase
Dimorphic fungi in this pahse can grow on media with cyclohexamide or antifungal.
yeast/tissue/parasitic phase
This is when fungi have a dark pigment.
dematiacious
This is when fungi have an absence of color.
hyaline
Battery recommendations for growth of fungi is with or without ________, with or without __________, and antibacterial agents.
blood
cycloheximide
What size culture tubes are recommended for growth of fungi?
large culture tubes (150x25mm)
What are three advantages of large culture tubes?
easily stored, less space
easily handeled, less hazardous
lower dehydration
What are two disadvantages of large culture tubes?
poor isolation
reduced surface for growth
______ plugged tubes are unsatisfactory for growth of fungi.
cotton
what are three advantages of petri-dishes for growth of fungi?
provide larger surface of growth
mixed culture easier to separate
provide maximum aeration
what are two disadvantages of petri-dishes for growth of fungi?
tendency to dehydrate during incubation
hazardous for cultivation of certain systemic mycoses
What are the three systemic mycoses that are hazardous for cultivation on petri-dishes?
histoplasma
blastomyces
coccidioides
what is the BHI agar used for primary recovery of fungi?
BHI agar w/out and with antibiotics
What are the two antibiotics added to make media selective for fungi?
Chlorampenicol
Cycloheximide
What is the broad spectrum, bacteriostatic antibiotic used to make media selective for fungi?
Chloramphenicol
What is the inhibitory antibiotic that also inhibits saprophytic fungi?
cycloheximide
mold/fungi should be incubated at what temperature on the BHI agar?
20oC
yeast should be incubated at what temperature on the BHI agar?
350C
BHI agar is used for recovery of _________ and _________ fungi.
saprobic
pathogenic
SABHI agar is used for isolation of significant fungi from __________ specimen (i.e. sputum)
mixed flora
SABHI agar is used for isolation of _________ and pathogenic fungi.
saprobic
This fungus selection agar is also used for isolation from specimen with normal flora for _________.
dermatophytes
this medium is selective for dermatophytes for screening purposes only.
dermatophyte test medium (DTM)
Dermatophytes infect what three parts of the body?
skin
hair
nails
this agar is used for nutritionally deficient C. albicans which produce chlamydospores.
corn meal agar
This agar is used for differential ID of aspergillus species.
Czapek's agar
All mold cultures and clinical specimens must be handled in what class BSC?
class II
Spore and hyphae stain gram ________.
positive
Candida albicans appear as what color in grams stain?
black
what percent KOH is used for direct microscopic examination of fungi?
40%
this is used for demonstrating fungal hyphae and spores in clinical material.
Potassium hydroxide (KOH)
KOH clears opaque material and hydrolyzes the _________ in epithelium.
keratin
This is used to detect mycoses in infected hairs by fluorescing a bright, yellow-green light
Wood's black light
before using a wood's black light the affected skin should be washed with what?
70% isopropanol
_____ may accelerate clearing process in KOH (may be overdone).
heat
under KOH examination hyphae demonstrate what?
uniformity in size and symmetry
these appear as branching hyphae, occasional arthrospores in KOH.
dermatophyte
These appear as short, stubby hyphal elements and grape-like clusters of spores in KOH.
Tinea versicolor
This appears as pseudohyphaer and chlamydospores/blastospores in KOH.
Candida
Hyphae do not grow __________ (e.g. sharp acute or right angles)
geometrically
Fungal morphology using ______ mounts is the basis of textbook descriptions of fungi.
LCB
This stain, used for fungi, is fungicidal and sporicidal
Lactophenol Cotton Blue (LCB) stain
Fungal mycelium and fruiting structures take on what color in the LCB stain?
delicate light blue color
What are the two types of negative stains?
india ink
nigrosin stain
Negative stain is routinely utilized for staining what?
CSF
Negative stain demonstrate large capsules enveloping bastospres of what organism?
Cryptococcus neoformans
The germ tube test is used to ID what organism?
Candida albicans
What is the reagent used in the germ tube test?
0.5 ml serum (human, rabbit, bovine)
the germ tube test should be incubated for how long at 35oC.
2 hours
the germ tube test is not valid if examined after __ hours.
2
in this test yeast species are differentiated based on carbon and nitrogen usage.
Yeast assimilation test
if the yeast assimilation test is positive it will show what?
growth or turbidity
what are the three commercial kits used for yeast assimilation test?
API 20C
Vitek yeast card
YT microplate
This fungi test consists of an organism suspension plus carbohydrate, if positive it will show gas bubbles.
yeast fermentation test
This test is rarely used because it has a long incubation and has been replaced with the assimilation test, used as a backup.
Yeat fermentation test.
this test was designed for microscopic examination of fungi in its natural state, dermatophytes only.
Slide technique
What are the two materials used in the slide technique for fungi?
SAB-DEX medium
Long coverslip (sterile)
What is the fungi stain used for the slide culture procedure?
LCB stain
This fungi procedure uses dissecting needles or pointed applicator sticks to dig out small portion of colony to be examined and tease it apart.
tease mount
doing this to colonies disrupts delicate fruiting structures of filamentous molds.
teasing
This fungi preparation is better suited to preserve spore arrangements, especially delicate filamentous molds.
scotch tape preparation
The scotch tape prepartion procedure can be used from what two sources.
culture
skin
the scotch tape prepartion can be used from skin for the diagnosis of what?
tinea versicolor
this stain is used to detect fungi and fungal elements, nocardia spp. do not stain well.
periodic acid schiff (PAS)
This stain is used with a fluorescence microscope along with KOH. fungal elements show apple-green or blue-white fluorescence.
calcocluor white
This type of mycoses causes superficial scaling and rarely invades depper tissues.
Cutaneous mycoses (sperficial)
Cutaneous mycoses demonstrate __________ and _________ only.
hyphae
arthrospores
clinical types of cutaneous mycoses are designated by __________ binomia.
latin (tinea capitis)
This is the most important cause of tinea capitis in school children.
Microsporum audounii
This is spread by direct contact with infected haris on caps, hats, combs, clippers, causes hair to fluoresce.
Tinea capitis
This causes an inflammatory Tinea capitis, zoophilic, ususally acquired from puppies and kittens.
Microsporum canis
This is the most common species of fungi isolated, causes T. barbae, T. capitis, T. corporis, T. pedis, and onychomycosis.
Trichophyton mentagrophytes
This is the second most common fungal species isolated, causes T. pedis, T. corporis, T. cruris, onychromycosis.
Trichophyton rubrum
This is the causative organism of Tinea versicolor.
Malassezia furfur
This causes T. corporis and T. capitis recovered from hair and skin.
Microsporum gypseum
This organism is associdated with tinea cruris and Tinea pedis.
epidermophyton flocossum
This organism is associated with cutaneous candidiasis/moniliasis, systemic dx in immune compromised, and Thrush.
Candida albicans
this type of mycoses is caused by fungi inhabiting soil/decaying vegetation, usually induced by trauma. Some individuals predisposed to systemic infections.
Subcutaneous mycoses
This organism is hazardous to gardeners, florists, causes sporotrichosis or "rose gardener's dx"
Sporothrix schenckii
This type of mycoses is soid fungi involved, and causes infections due to inhalation of spores, disseminated forms invade organs.
Systemic (deep) mycoses
This is the causative organism of coccidiomycosis or "Valley fever".
Coccidioides immitis
This is the causative organism of histoplasmosis, or "Spelunker's dx," found in bat and pigeon droppings.
Histoplasma capsulatum
This organims is often confused with Leishmania because it has a similar morphology and found in RE system.
Histoplasma capsulatum
This organism causes blastomycosis.
Blastomyces dermatitidis
This organism causes paracoccidiomycosis.
Paracoccidoides brasiliensis
These are nonpathogenic fungus that cause subcutaneous and disseminated infection in immunosuppressed or debilitated patients.
opportunistic mycoses
What is the treatment for opportunistic mycoses?
corticosteroids
cytotoxic drugs
antimicrobials
This is an opportunistic mycoses that produces large, ribbon-like hyphae, ID by presence/absence of rhizoids, structure and position.
Zygomycetes
What are the three commonly encountered zygomycetes?
Rhizopus
mucor
absidia
this opportunistic mycoses caues cryptococcosis.
cryptococcus neoformans
This opportunistic mycoses causes aspergillosis, and is the most frequently encountered fungus in the lab.
Aspergillus
What is the most common species of Aspergillus?
A. fumigatus
this opportunistic mycoses is isolated from mucocutaneous infection to disseminated infection.