Microbiology - Fungus

Front 1

Diagnostically useful fungal antigens:
Galactoxylomannan
Histoplasma capsulatum surface antigens
Candida albicans enolase
Galactomanna

Back 1

Diagnostically useful fungal antigens:
Galactoxylomannan: Cryptococcus neoformans
Histoplasma capsulatum surface antigens: Histoplasma capsulatum
Candida albicans enolase: Candida albicans
Galactomanna: Aspergillus fumigatus

Front 2

Diagnostically useful fungal antigens:
Cryptococcus neoformans
Histoplasma capsulatum
Candida albicans
Aspergillus fumigatus

Back 2

Diagnostically useful fungal antigens:
Cryptococcus neoformans: Galactoxylomannan
Histoplasma capsulatum: Histoplasma capsulatum surface antigens
Candida albicans: Candida albicans enolase
Aspergillus fumigatus: galactomannan

Front 3

Name 3 pathogenic species of Aspergillus.

Back 3

A. fumigatus
A. flavus
A. niger

Front 4

Morphology of Aspergillus?

Back 4

Narrow septate hyphae branching at acute angles.

Front 5

This condition, in which Aspergillus mold colonizes the airway wihtout invasion, is characterized by marked allergic response (mucus impaction, peripheral eosinophilia, and reactive airways.) The inflammaotry response can be sufficiently severe to cause hemoptysis and eventaul bronchiectasis. This is often seen in patients with ectopic history or patients with cystic fibrosis. The diagnosis can be supported with tests for serum anti-Aspergillus IgE.

Back 5

Allergic bronchopulmonary aspergillosis

NOTE: In addition to A. fumigatus, A flavus is a common cause of ABPA.

Front 6

What is the colon color?
- A. fumigatus
- A. flavus
- A. niger

Back 6

- A. fumigatus: dark green
- A. flavus: yellow
- A. niger: black (only on top, white on bottom)

Front 7

Name 3 pathogenic Zygomycetes.

What are the common properties of Zygomycetes?

Back 7

Pathogens:
1. Rhizopus
2. Mucor
3. Absidia

Common properties: Broad, aseptate hyphae, branching at 90 degree angles

Front 8

Name 3 major genera of dermatophytes.

Back 8

Trichophyton
Epidermophyton
Microsporum

Front 9

This Aspergillus species has circumferential phialides and resembles a lollipop.

Back 9

A. flavus

Front 10

This Aspergillus species has a single row of phialides, each of which gives rise to a chain of coniia that cover only the top of the vesicle.

Back 10

A. fumigatus

Front 11

This Aspergillus species has heavily pigmented conidia.

Back 11

A. niger

Front 12

This Zygomycete produces rhizoids and sporangiophores that arise nodally (directly over the rhioids). Their sporangia are prominent shperical strucutres full of tiny spores which tend to colapse when mature resembling a collapsed umbrella.

Back 12

Rhizopus

Front 13

This Zygomycete produces rhizoids but its sporangiophores arise internodally (between rhizoids). Their sporangia are prominent spherical structures.

Back 13

Absidia

Front 14

This Zygomycete does not produce rhizoids. Their sporangia are large spherical structures that tend to fall apart, releasing their numerous spores.

Back 14

Mucor

Front 15

What is the medical treatment for mucormycosis? (Infection with a Zygomycte)

Back 15

Amphotericin B

Front 16

This dermatophyte has macroconidia which are spindle-shaped structures with pointed and somewhat upturned ends and transverse septae.

Back 16

Microsporum canis

Front 17

This dermatophyte has oval macroconidia with plunt ends and transverse septae.

Back 17

Microsporum gypseum

Front 18

This dermatophyte has macroconidia which are club-shaped with transverse septae. Microconidia are never produced.

Back 18

Epidermophyton flocosum

Front 19

This dermatophyte has tear-shaped microconidia spaced along the hyphae, giving a birds-on-a-wire appearance.

Back 19

Trichophyton rubrum

Front 20

This dermatophyte has microconidia arranged in grape-like-clusters and occasional spiral hyphae.

Back 20

Trichophyton mentagrophytes

Front 21

This dermatophyte has marked size and shape variability in microconidia.

Back 21

Trichophyton tonsurans.

Front 22

Which Candida species is fluconazole susceptible?

Back 22

Candida albicans. Most other Candidas are resistant to fluconazole.

Front 23

This Candida species has characteristic blastoconidia and chlamydospores. The tight clusters of blastoconidia are arranged at set intervals along the length of pseudohyphae, and chlamydospores are found at the termini of pseudohyphae.

Back 23

C. albicans

Front 24

This Candida species does not produce pseudohyphae.

Back 24

Candida glabrata

Front 25

This Candida species has short, curving pseudohyphae with round to oval blastoconidia.

Back 25

C. parapsilosis

Front 26

This Candida species has multibranched pseudohyphae, blastoconidia borne singly or in chains form along pseudohyphae.

Back 26

C. tropicalis

Front 27

This Candida species has short, curved pseudohyphae with blastoconidia at or between septae.

Back 27

C. lusitaniae

Front 28

This Candida species has branching pseudohyphae with elongated blastoconidia.

Back 28

C. krusei

Front 29

Which Candida species is positive for the germ tube test?

Back 29

C. albicans

Front 30

What are the two main pathogens in the Cryptococcus genus?

Back 30

C. neoformans
C. gattii

Front 31

India ink is used to show the polysaccharide capsule of this organism.

Back 31

Cryptococcus

Front 32

Is Cryptococcus budding narrow or broad based?

Back 32

Can be interpreted as either due to the polysaccharide capsule. The key feature to observe in tissues is the size variability of Crypotococci. Small ones can be as small as Histoplasma capsulatum and large ones can be as big as Blastomyces dermatitidis. In cultures the organisms grow as yeasts surrounded by even spaces (due to the capsule)

Front 33

Which Cryptococcus is associated with pigeon droppings and soil?

Back 33

Cryptococcus neoformans

Front 34

Which Cryptococcus is associated with Eucalyptus trees in Australia, Southern California, and Pacific Northwest.

Back 34

Cryptococcus gattii

Front 35

Which fungus has a "spaghetti and meatballs" morphology?

Back 35

Malassezia furfur

Front 36

Name 6 clinically significant dimorphic fungi.

Back 36

Coccidioides immitis
Blastomyces dermatitidis
Histoplasma capsulatum
Sporothrix schenckii
Paracoccidioides braziliensis

Front 37

This dimorphic fungus has a worldwide distribution, most frequently found in gardens and plant material. Inoculation occurs via trauma resulting in local inflammation and spread via lymphatics.

Back 37

Sporothrix schenckii

Front 38

This dimorphic fungus grows as black mold. Microscopically the mold form is characterized by "florettes" of conidia. The yeast form is composed of 2-5 micrometer elongated cigar shaped forms with narrow-based budding.

Back 38

Sporothrix schenckii

Front 39

This dimorphic fungus can be seen as small intracellular organisms with narrow-based budding in histiocytes.

Back 39

Histoplasma capsulatum

Front 40

This dimorphic fungus is most commonly found in the Ohio and Mississippi River valleys where it is found in soil contaminated by feces from chickens, birds, and bats.

Back 40

Histoplasma capsulatum

Front 41

The geographic region for Histoplasma capsulatum?

Back 41

Ohio and Mississippi River Valleys

Front 42

The mold form of this dimorphic fungus has spiked macroconidia with mariner wheel morpholgoy.

Back 42

Histoplasma capsulatum

Front 43

This dimorphic fungus is found in dogs of the Eastern US, eastern Midwest, and Africa.

Back 43

Blastomyces dermatitidis

Front 44

This dimorphic fungus appears as fairly uniform, 8-12 micrometer yeasts with broad-based budding.

Back 44

Blastomyces dermatitidis

Front 45

This dimorphic fungus initially affects lungs, but can disseminate and preferentially involves skin and bone.

Back 45

Blastomyces dermatitidis

Front 46

Which is the most dangerous dimorphic to have in the lab?

Back 46

Coccidioides immitis

Front 47

This dimorphic fungus is found in California, Texas, and Arizona.

Back 47

Coccidioides immitis

Front 48

What is the geographic distribution of Coccidioides immitis?

Back 48

California, Texas, and Arizona

Front 49

People with what ABO blood group are more at risk for disseminated Coccidioides immitis infection?

Back 49

Type B

Front 50

This dimorphic fungus has a mariner's wheel appearance of yeast forms.

Back 50

Paracoccidioides brasiliensis

Front 51

This dimorphic fungus is endemic to Central and South America.

Back 51

Paracoccidioides brasiliensis

Front 52

What is the geographic distribution of Paracoccidioides brasiliensis?

Back 52

Central and South America