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138 Cards in this Set

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Fungi General Characteristics

  • Eukaryotic
  • Heterotrophic
  • Polymorphic

Cell wall contains

chitin

Cell membrane contains

  • egosterol
  • mannans
  • glucans

Phyla

  • Ascomycota
  • Basidiomycota
  • Zygomycota
  • Deuteromycota "Fungi imperfecti"- no sexual form
  • Chytridiomycota- agriculture, cold blooded animals

Classes

  • Ascomycetes- Saccharomyces, Candida, Coccidiodies, Aspergillus, Fusarium, Curvularia
  • Basidiomycetes- Cyrptococcus, tirchosporon, Malesezzia, Rhodotorula
  • Zygomycetes- Order- Mucorales- Mucor, Rhizopus, Rhizomucor, Cunninghamella

Yeast

  • Candida

  • Cryptococcus

  • Malasezzia

  • Trichosporon

  • Rhodotorula

  • Geotrichum

Dimorphic

  • B. dermatitidis

  • H. capsulatum

  • C. immitis

  • P. brasilensis

  • S. schenkii

  • P. marneffi

Hyaline


  • Aspergillus
  • Fusarium
  • Gliocladum
  • Paecilomyces
  • Penicillium

Zygomycete

  • Scedosporium
  • Scopulariopsis
  • Trichoderma
  • Absidia
  • Cunninghamella
  • Mucor
  • Rhizopus
  • Rhizomucor

Dematiaceous

  • Alternaria
  • Bipolaris
  • Cladosporium
  • Curvularia
  • E. jeanselmei
  • Foncea

Dermatophytes

  • Microsporium
  • Trichophyton
  • E. floccosum

True Hypae

  • Parallel sides
  • Non septate
  • no constrictions

Pseudohyphae

  • not necessarily parallel
  • maybe septate
  • constricted

Chromagar C. ablicans

green

Chromagar C. tropicalis

steel blue

Chromagar C. krusei

dark purple

Chromagar C. glabrata

light pink

How to ID Candidiasis

Find pseudohyphae and blastoconidia

Candidiasis

  • Normal floraPerson-to-person, Exogenous/endogenous
  • Superficial to desseminated, hemotogenous route
  • Erythematous, diaper rash, onychomycosis, thrush, cheilitis
  • Pregnant, DM, antibiotics, HIV, steroid use
  • Initiates inflamm. and cell-med immunity

Yeast with growth at 42C


  • C. ablicans
  • C. krusei

Yeast that grow in the presence of cycloheximide

  • C. albicans
  • C. dublinensis
  • C. tropicalis
  • C. parapsilosis
  • C. keyr
  • C. guilliermondii

Germ tube positive


  • C. albican
  • C. dublinensis

Candida negative for Cycloheximide, growth at 42, and germ tube

C. lusitaniae

Differentiate C. dublinensis and C. albicans

  • C. albicans Methy-D-glu +

  • C. dublinensis: more chlamydospores than C. albicans

C. albicans Characteristics

  • Macro: smooth white colonies with feet like extensions
  • Micro: sparse hyphae, 90 deg branching, terminal chlamydospores
  • 50% of candidiasis cases

C. glabrata characterisitics

  • Grows better on EMB than SBA
  • Resistant to azole antifungals
  • UTIs
  • Small ovoid yeast

C. tropicalis characteristics


  • Candidemia in oncology patients
  • Leukemia patients
  • Sparse single or short chained blastoconidia
  • Between septa of pseudohyphae

C. parapsilosis characterisitics

  • High MIC for echinocandins

  • Candidemia in pediatrics

  • fake fingernails

  • short much branched pseudohyphae

  • Spider like/tree like pattern

  • 2-3 blastoconidia in small clusters

  • Endocarditis/Endophalitis

C. krusei characterisitics

  • Resistant to fluconazole
  • Fallen tree or matchstick hyphae
  • Blastoconidia large and oval
  • Granulopenia
  • BM transplants

C. keyfr (pseudotropicalis) characteristics

  • Resistant to antifungals
  • Cigar shaped highly branched pseduohyphae
  • "logs in a stream"
  • Catheter related

C. guilliermondii characterisitic

  • Cutaneous infections
  • Short pseudohyphae
  • Small groups of blastoconidia at septate

C. lusitaniae characterisitics

  • Develops resistance to Ampho. B
  • pseudohyphae slenders branched and curved
  • Short chains elongate blastoconidia
  • Hospitalized/opportunistic infection

C. neoformans

  • Serogroups A and D

  • Pulmonary can desseminated to CNS

  • Associated with pigeons, chickens, or turkey

  • HIV pts with CD4 counts less than 100

  • Basidiomycete: resistant to echinocandins

  • Lateral budding no pseudohyphae

  • +: inositiol, urea, india ink, caffeic acid

  • =: cycloheximide, CGB

C. gatti

  • Associated with eucalyptus in India
  • Canavanine glycine bromothymol blue +
  • non-immunocompromised can be affected

Dimorphic fungi are all

  • Pathogens
  • Slow growers
  • Evade the immune system by phase shift

Culture considerations for Dimorphic yeast


  • Yeast: 24-48hrs, 37C
  • Mold: LCB stain, tease prep, Agar slide, Growth at Room temp.

Blastomyces dermatitidis / Blastomycosis

  • Inhalation 50% asymptomatic
  • Resembles TB; abcess with granuloma can become chronic
  • Yeast: broad based budding yeast yellow to buff
  • Confuse with T. rubrum, Scedosporium apiospermum
  • Mold: grey white light buff, hyaline hyphae delicate, condiophore at right angles, conidia: unicelllular oval pyriform "lollipops"

Histoplasma capsulatum/Histoplasmosis

  • 95% asymp.
  • dubosii- Africa no pulmonary
  • Soil rich in bird/bat droppings
  • RES/thyroid, can be found in blood (mononuclear cells)
  • Calcifications in liver, lungs, spleen can detect capsular Ag
  • Yeast: narrow based budding yeast yellow white
  • Mold: white turns grey to grey brown, macro(large tuberculate with fingerlike projections) and microconidia(short lateral pegs)

Coccidioides immitis

  • Virulent, no yeast at 37C, windborne in dust
  • 60% + skin test
  • Chronic coin lesions
  • Systemic pulmonary to lung, skin, bones, meninges
  • Spherule: granulomatous
  • Mold: grey white, barrel shaped arthroconidia with disjunctor cells

Paracoccidioides brasiliensis/Paracoccidioidomycosis

  • In soil, fruit bats, armadillos
  • South and Central america
  • Pulmonary, tooth loss, cervical lymphoadeno.
  • can surface 10-20 years after exposure
  • disseminates to lymph nodes, skin, mucous membranes
  • Yeast: mariners wheel
  • Mold:BHI agar 10-20 days, R: yellow brown

Penicillium marneffei

  • Opportunisitic/inhalation pulmonary
  • Acne-like pimples
  • Mold: bluish-grey green with white edges, R: red pigment, resemble penicillium
  • Yeast: slightly pink glabrous, round to oval yeast fission

Sporothrix Schenckii/Sporothrichosis

  • Tropics/Subtropics
  • Direct inoculation
  • Subacute to chronic cutaneous/subcutaneous
  • osteoarthritis
  • Mold: grey whit turns brown/brown black, delicate conidiophores rosettes
  • Yeast: white turn buff brown to brown black, oval to elliptical single bud, cigar shape

Anamorph


  • asexual stage
  • hyphae
  • arthroconidia
  • spherules

Telomorph


  • sexual form

Hyaline general characteristics

  • Saprophytic
  • slow growers
  • cycloheximide =

Hyalohypomycosis

  • Tissue morphology is mycelial

  • Acute invasive illness in immunocomp.

  • prolonged granulocytopenia

  • receiving antibiotics for fever

  • Hyphae irregular branch at 45 and 90

  • Phialides conidia in closed lesions

Mycetoma

  • Tumefaction

  • Draining sinuses

  • Sclerotic granules

  • Hyaline and dematiaceous

Aspergillosis


  • Fungus ball (Aspergilloma_
  • Allergic rhinitis
  • Nail infection
  • Mycotoxiosis: A. flavus, A. versicolor, A.nidulans
  • dichotomous branching 45
  • Radial pattern
  • Hyphae parallel

Hyaline cutlure


  • Sputum, BAL
  • Lungs, sinus, skin, heart,
  • No blood culture
  • Media: SAB, BHA, IMA
  • Differential: Tryptone, Ferric ion (yellow pigment), rapid growth

Scedosporium boydii

  • Asexual: mycetoma hand or feet, cycloheximide +
  • Phaeohyphomycosis
  • Sexual state: Pseudoallescheria boydii

Aspergillus fumigatus

  • Respiratory sinusitis
  • Most common aspergillosis. Will grow at 45
  • Rapidly growing granular: blue green slate grey R: white to yellow
  • Conidiophores: short colorless
  • Uniseriate
  • Philaides 3/4 around
  • Chains of round conidia

Aspergillus flavus

  • Aflatoxin, liver damage liver caner
  • Rapidly growing granular yellow olive-green R: white-yellow
  • Rough round conidiophore
  • vesicle: Biseriate/Uniseriate
  • Entire vesicle round smooth or rough

Aspergillus niger

  • ear infections
  • black powdery
  • R: cream
  • Conidiophore: long smooth
  • Round vesicle Biseriate
  • philalides around entire vesicle

Aspergillus terreus

  • nail, skin, eye, systemic
  • Amphotericin B resistnat
  • Cinnamon-tan R: white to tan
  • Short compact columnar heads
  • Biseriate phialides cover top half of vesicle
  • round chains of conidia

Aspergillus ustus

  • Rare cutaneous pathogen
  • Infection in solid organ transplant
  • decreased susceptibility to anitfungals
  • Grow on 25C potato
  • Yellow diffusing pigement Exudate: clear-yellow to purple bronw
  • Hulle cells: sexual state

Acremonium

  • Mycetoma, corneal, nail infection, rarely invasive
  • compact surface folded; overgrown whitel cottony aerial
  • White grey or rose in color R: colorless
  • Delicate fine narrow hyphae septate unbranched
  • Tapered phialides small oblong 1-celled conidia in clusters at tips of phialides

Penicillium

  • Most don't grow at 37C

  • Cycloheximide =

  • initially white to blue-green, grey-green olive R: white

  • Simple/branched conidophores

  • Flask shaped phialides form brush like clusters conidia round unicellular in chains

Gliocladium

  • Contaminant rarely a disease

  • Fluffy white pinkish green at center R: white

  • Similar to penicillium conidia clump forming balls

Paecilomyces variottii

  • cycloheximide =
  • conidia elliptical
  • tan yellow brown to olive green R: white
  • 2-7 long flask shaped phialides in clusters
  • grows in less than equal to 50C

Paecilomyces lilacinus


  • cycloheximide =
  • conidia elliptical
  • pink mauve or lilac R: white
  • Flask shaped phialides
  • Chains of conidiophores at tip of phialides
  • grows in less than or equal to 37C

Fusarium

  • Fusariosis

  • Ocular infections, Fungal blood culture

  • wooly to cottony white to pink to purple R: white to pink

  • Phialides branched/unbranched

  • Macroconidia 2 or more celled thick walled canoe shape, Micro: arranged in balls on simple conidiophores

Scopulariopsis

  • Nail infections/BM transplant pts
  • Cinnamon brown grey or creamy
  • Chains of single anneloconidia basiptal succession in groups or alone
  • Conidia: round to lightbulb shape usually truncate
  • Smooth to rough hyaline to brown in color
  • Brumptii: chains, Brevicalus: fans

Processing Superficial/Cutaneous

  • Hair (base), skin (margins), nails (nail beds)

  • KOH/calcofluor

Processing tissue

  • can add saline or broth
  • Mincing: zygomycetes
  • Grinding: H. capsulatum

Processing blood/Bone marrow

  • blood culture bottle
  • Lysis centrifugetion system: Wampole isolator
  • Biphasic blood culture (liquid agar)

Processing CSF


  • Centrifuge to concentrate
  • Incoulate microscopically examine
  • India ink
  • CALAS
  • can follow quantitatively over time

Processing sputum

  • No NALC/NaOH (reserve for Mycobacterium)
  • Select blood, pus, or caseous material since dimorphic yeast can grow in TB agar

Periodic Acid-Schiff

  • Color of Fungi: Magenta (must be alive)
  • Background: pink or green
  • Detects glycogen

Gomori Methenamine silver

  • Color of fungi: black

  • Background: green

  • Detects: carbohydrates

  • Dead or alive and Pneumocystic

Giemsa


  • Yeast: Purple-blue , halo for capsule
  • Background: pink-purple
  • Detect: A-T

India Ink


  • Yeast with clear halo
  • Background: black

KOH

  • Refractile
  • Background: Clear

KOH-Calcofluor white

  • Fluorescent

  • Background: Dark

  • Chitin and Cellulose

Masson-Fontana

  • Fungi: Brown

  • Background: pink-purple

  • Melanin

  • Dematiaceous

  • Cryptococcus

H&E


  • Aspergillus and Zygomycetes use with GMS
  • Fungi: Pink-red
  • Background: Pink
  • Visual of host response to organ

Funigflour wet mounts

  • Can't determine pigment

  • Yeast, mold, pneumocytosis

  • beta-linked polysaccharide in cell wall of fungi

Plates for yeast

  • BAP
  • CNA
  • SDA
  • Emmon's Agar decrease glucose, more neutral pH

Plates for mold

  • SDA/SAB

  • Potato- enhance reproductive structures

  • BHI-dimorphic

  • Inhibitory- chloraphenicol+gentamicin

  • Mysocel- chloraphenical+ cycloheximide

  • RT or 37C dimorphic 4-6 weeks

Microscopic Exam Fungal Growth

  • Scotch tape
  • Slide
  • Tease
  • Use lactophenol blue

Zygomycetes General Characteristics

  • Rapidly growing
  • lid-lifters
  • steel wool appearance
  • fast progressing disease: tissue destruction eventual dissemination
  • Large aseptate hyaline hyphae

Rhinocerebral


  • sinus/brain
  • pulmonary
  • cutaneous

At Risk for zygomycetes

  • DM
  • HIV
  • immunocompromised
  • hematological malignanices
  • transplant patients

Rhizopus

  • Most common isolates
  • Macro: white grey R: white
  • Sporangiophores: long unbranched
  • Rhizoids: nodal
  • Sporangium: round sproangium
  • Columella: spherical or elongated
  • Best growth at 45C

Absidia

  • Macro: white R: grey
  • Sporangiophores: branched
  • Rhizoid: internodal/sparse
  • Sporangium: present
  • apophysis: funnel shaped

Mucor

  • Macro: flat growth R: white
  • Sporangiophores: short-curved, long-straight, branched or unbranched
  • Sporangium round hyaline or dematiaceous round
  • grows best <37C

Rhizomucor

  • Zygomycosis in leukekmia patients
  • inhibited by cycloheximide
  • Sporangiophores: long branched, internodal branched irregular short
  • Sporangium: round

Cunninghamella

  • Rare
  • aggressive zygomycetes
  • Macro: grey R: white
  • Micro: long branched-sporangiophore end in swollen vesicles covered in spine like dentricles contain sporangiolum

Syncephalastrum

  • Contaminant, dark grey R: white

  • Sporangiophores: short branched sporangiophores terminate in round vesicles each covered in chains of round spores enclosed in tubular sporangia

Dematiaceous General Characteristics

  • Darkly pigmented
  • Produce melanin
  • Wet mount: pinched sausage shaped hyphae
  • Opportunisitic
  • Contaminate puncture wounds
  • Can lead to pneumonia
  • Macroscopic: dark colored reverse
  • Microscopic: Pigmented septate microcondia

Dematiaceous Disease states

  • Chromoblastomycosis
  • Phaeohyphomycosis
  • Eumycotic mycetoma

Chromoblastomycosis

  • Cutaneous/Subcutaneous tissue

  • Sclerotic bodies (copper pennies); binary fission

  • Chronic slowly progressive

  • crusted, verrucose, wart-like lesion

  • bare foot population tropics, decaying vegetative soil

  • F. pedrosoi, P. verrucosa, E. jenaselmei, Cladiophora, Rhinocladiella

Phaeohyphomycosis

  • Fungal sinusitus

  • granulomas (no granules)

  • primary cutaneous in immunocompromised

  • subcutaneous infections

  • BRAIN ABSCESS (systemic)

  • "string of beads"

  • worldwide

  • Alternaria, Bipolaris, Edermatididitis, E. jeanselmei, Black piedra, Tinea Nigra

Eumycotic Mycetoma

  • Subcutaneous infection
  • Tumor like lesions w/ granules
  • Fibrosis: long standing infection
  • Tropics
  • Can be caused by hyaline infections
  • Nocardia, Streptomyces, Actinomadura, P. boydii, Rhinocladiella, Madurella, E. jeanselmei, Curvularia, Phialophoria

Molds with yeast like colonies

  • Black yeast like
  • Exophila jeanselmei
  • Exophilia (Wangiella) dermatitidis
  • Hortae werneckii

Molds with multi-celled conidia


  • Muriform: transverse and vertical septate: Alternaria, Ulocladium (contaminant)
  • Transverse: Bipolaris, Curvularia, Exserohilum

Molds with single cell conidia

  • All types: Fonsecaea
  • Single: Rhinocladiella
  • Chains: Cladosporium, Cladophialophora
  • Clusters: Phialophore

Exophiala jeanselmei

  • Mucoid olive brown R: dark brown
  • Slow grower 25-37C
  • brown septate hyphae
  • brown phialides cylindrical
  • oval brown unicellular conidia in clusters
  • Chlamydospores may be present

Exophila (Wangiella) dermatitidis


  • Mucoid olive brown R: dark brown
  • Slow grower 25-37C
  • brown septate hyphae
  • Young: budding yeast Older: hyphae phialides
  • Phialides brown, flask shaped lack collarettes
  • brown conidia clusters at ends of phialide and down side of conidiophore

Alternaria

  • Muriform
  • Multi-celled
  • brown simple conidiophores
  • chains of beak like apical cells
  • angular cross wall tapered at distal end

Bipolaris

  • Multi-celled
  • transverse septate
  • Allergic sinusitis
  • brown geniculate conidiophores
  • brown conidia fusoid 3-6 cells

Curvularia

  • Multi-cells
  • transverse septate
  • eyes and sinuses
  • brown simple or branched conidiophores
  • slightly curved conidia
  • central cell grows faser, sympoidal conidiophores (boomerang)

Exerohilum

  • nasal, sinus, skin cornea
  • pencil shaped smooth walled macroconidia
  • thickening of the outer wall
  • nipple like extensions

Fonsecaea pedrosoi

  • conidiophores cylindrical inflated tip
  • conidia unicellular ellipsoid to round, formed sympodially in successive rank
  • chains longer than 5 cells
  • chromoblastomycosis in South America

Phialophora verrucosa

  • 2nd most common agent of chromoblastomycosis
  • can cause phaeohyphomycosis
  • phialides vase shaped with cup like collaretted
  • round to oval conidia at tip of phialides

Cladophialophora carrionii

  • olivaceous-black in color chains
  • single cell clusters

Rhinocladiella

  • singular cell clusters

Tinea nigra Hortae

  • Mold
  • Phaeoannellomyces werneckii
  • palms of hand, soles of feet
  • outermost layer of skin hyper keratosis

Black piedra

  • Piedraia hortae
  • Dematiaceous fungi
  • Hard black nodules outside scalp hair

White piedra

  • soft white nodules shaft of hair
  • Trichosporon ovoides (scalp)
  • Trichosporon inkin (pubic)

Trichosporon

  • Yeast like, superficial cutaneous infections
  • Hyphae, blastoconidia, arthroconidia
  • Urea +
  • Cycloheximide -
  • Non-fermenter
  • Resistant to ecchinocandins
  • Cross reacts with ELISA for cryptococcal Ag test

Geotrichum

  • Yeast like colonizes human respiratory/GI tract
  • Rare/opportunistic infections
  • Geotrichosis
  • Optimal growth at 25C
  • Non fermenter
  • Urea: variable
  • consecutive formation of rectangular hyphae, no blastoconidia

Malassezia furfur

  • Tinea versicolor

  • Spaghetti/meatballs

  • superfical infection, hypopigment

  • requires long chain fatty acid, overlay SAB with olive oil

  • daughter cell from collarettes (bowling pins)

Saccharomyces cerevisae

  • intestinal tract
  • Rarely cause infection
  • Acid fast: ascospores
  • urease =
  • large oval blastoconidia
  • multipolar budding
  • no hyphae/pseudohyphae

Rhodotorula

  • Yeast associated with water source
  • Rarely causes infection
  • Basidiomycete
  • Red, pink, orange yeast
  • Grows at RT
  • Urease +
  • Non fermenter
  • No hyphae/pseudohyphae

Tinea/Ringworm

  • Fungal infection of the skin/hair/nails
  • ring-shaped may be raised itchy
  • person to person contact, fomites, animals

Dermatophytes

  • Microsporum, Trichophyton, Epidermophyton

  • no living tissue invaded

  • extracellular enzymes hydrolyze keratin

  • allergic and inflammation response to host

  • Endothrix- in the hair shaft

  • Ectothrix-form a sheath of spores on the outside of the hair as well as with in

Geophilic

M. gypseum

Zoophilic

M. canis

Antrhopophilic

Trichophyton tonsurans

Dermatophytosis

  • Symptoms 4-14 days itching, redness, scaling, ring shaped rash
  • abcess, cellulitis, hair falls out
  • Diagnosis: Wood's lamp, skin scrapings treated with KOH/fungal culture
  • Culture: 7-14 days must hold 21 days for negative

Trichophyton

  • Macroconidia: rare
  • Microconidia: abundant
  • Hair, skin, nail

Microsporium

  • Macroconidia: abundant
  • Microconidia: rare
  • Hair, skin

Epidermophyton

  • Macroconidia: abundant

  • Microconidia: never

  • skin, nails

Urease

  • Neg: T. rubrum
  • Pos: T. tonsurans, T. mentagrophytes

Hair perforation


  • Neg: T. rubrum
  • Pos: T. tonsurans, T. mentagrophytes
Woods lamp

  • Tinea (pityriasis) versicolor, fluoresces pale yellow/white
  • M. microsporum- blue-green

Head


  • Tinea capitis
  • Tinea favosa

Beard

Tinea barbae

Body

Tinea corporis


Tinea imbricata

Hand

Tinea manum

Nails

Tinea unguium

Groin

Tinea cruris

Feet

Tinea peds

T. rubrum

  • Most common dermatophyte

  • Skin, nails

  • anthropophilic

  • Urease/ Hair perforations:=, N/A nutrients

  • Slow growing white cottony R: water soluble red pigment

  • septated non pigmented hyphae

  • Micro egg shaped "birds on a fence"

  • macro-rare pencil shaped elongated

T. tonsurans

  • Most common cause of tinea capitis
  • Hair and skin
  • anthropophlic
  • Urease, Hair perf. +, thiamine
  • seude like folded center pale butt yellow brown R: deep mahogany
  • Elongated club shaped balloon shaped, small tear drop right angle to hyphae
  • Thin wall, clavate rare

T. mentagrophytes

  • sink, nails
  • zoophilic
  • Urease +
  • mod growing powdery white to cream R: yellow-brown to reddish brown

M.canis

  • woods lamp+
  • hair, skin
  • zoophilic
  • ectothrix
  • flat wooly to cottony white R: deep yellow
  • occasional club shaped
  • numerous thick wall spindle shaped multicelled knob like ends

E. floccosum

  • "jock itch"
  • onychomycosis of big toe nail
  • antropophilic
  • yellow- yellow tan raised and folded in center
  • many chlamydospore present
  • Beaver tails 2-6 cells single or clusters