Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

DWT Exam 4 > Bacteriology: Mycology > Flashcards

Bacteriology: Mycology Flashcards

1
Q

What is the cell membrane and cell wall of fungus made of?

A

Cell membrane has ergosterol rather than cholesterol
Cell wall made of chitin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What characteristic of chitin makes it easy to infect animals?

A

It is difficult to digest but it cannot make their own energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is yeast?

A

unicellular form of a fungus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is hyphae?

A

filamentous form of fungus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are pseudohyphae?

A

chains of yeast that look like hyphae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is mold?

A

a fungus that grows as a mass of hyphae (mycelium)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are dermatophyte?

A

fungal organism that causes ringworm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are endospores?

A

spore contained within a sac

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are dimorphic fungus?

A

fungi that exist as yeast forms in animal tissues & as hyphae in environment due to temperature differences.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 3 main ways that fungi grow?

A

1) budding yeast
2) germinating spore/conidia
3) fruiting body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the characteristics of budding yeast?

A

broad-based
narrow-based
asexual reproduction by budding
the type of budding allows us to differentiate between different oranisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the characteristics of germinating spore/conidia?

A

forms germ tube that can grow into a new organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the characteristics of fruiting body?

A

produce many conidia that are each very tiny & light & can be dispersed through the environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How can fungi spread?

A

locally by the release of conidia
aerosolized by the release of conidia into the air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What gives rise to the patchy appearance of mold?

A

The local and aerosolized spread of conidia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the 2 types of hyphae?

A

Septate & nonseptate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the characteristics of septate hyphae?

A

They have lines (septum) that divide the hyphae into “sections”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the characteristics of nonseptate hyphae?

A

There are no lines that divide the hyphae into section

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What types of conidia do Dermatophytes have

A

Arthroconidia and macroconidia and microconidia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are arthroconidia?

A

observation in patients
spores release during hyphal fragmentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are macroconidia?

A

observed in lab
big
allows for differentiation between dermatophyte species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What types of growth and reproduction do other fungi species have?

A

Fruiting bodies, clusters, small little buds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the factors that affect the development of fungal disease?

A

Virulence factors
Tissue affected
Host immunity
Geographic location
Environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How do we diagnose fungal infections?

A

Presumptive
Direct swab/observation
Culture
Antibody detection
Antigen detection

25
Q

What is the best diagnostic technique for superficial skin samples?

A

wet mount cytology

26
Q

What is the mounting fluid solution used for wet mount cytologies?

A

10% potassium hydroxide which clears cellular debris
New methylene blue
lactophenol cotton blue

27
Q

What types of stain do we use for routine fungal samples?

A

Diff-quick
Wright-Giemsa
H&E

28
Q

What types of stain do we use for special fungal samples?

A

Gamori’s methenamine silver: fungal wall takes up silver in the stain and appear black
Periodic acid-schiff (PAS)

29
Q

What techniques can we use in direct exam/observation?

A

Wet mount cytology
Stain/Reaction
Cytology
Impression smear
Histopathology

30
Q

What is the biggest draw back with fungal cultures?

A

They can take way to long and this can be dangerous with sever infections. Normal fungal culture can take 4 weeks or more

31
Q

What samples can we collect to send OUT and which is the best?

A

Fresh tissue/ fluid–BEST
Swabs– only when you cannot get a better sample

32
Q

What sort of transport conditions are necessary for samples to be sent OUT?

A

Overnight shipping to lab
dermatophytes: hair/nails/scales/ skin in a sterile container @ room temp
Room temperature samples if fungal disease is primary differential
send chilled on ice if bacterial contamination or differential

33
Q

What are the test that can be done IN-HOUSE?

A

DTM: dermatophyte test media
RSM: rapid sporulation media

34
Q

What are the characteristics/ draw backs of DTM?

A

has a pH indicator in media
starts yellow but changes to red/pink with growth of dermatophytes
false positives can occur if you wait to long to read results

35
Q

Why does the DTM media change color?

A

pH change occurs when organism eats protein in agar resulting in an ammonia by product, increasing the pH, allowing the agar to change color

36
Q

What are the infectious species of dermatophytes?

A

Mycosporum spp
Trichophyton spp.

37
Q

What disease does dermatophytes cause?

A

Ringworm

38
Q

What are the clinical signs of dermatophtophytosis?

A

Hair loss
Scales
Crusts
Red skin
Pruritis
Papules/pupstules

39
Q

How can you diagnose Dermatophytosis?

A

Woods lamp
Cytology (wet or dry))

40
Q

What liquid is used typically used for a wet mount dermatophyte cytology?

A

Potassium hydroxide

41
Q

What makes DTM turn red?

A

It has phenol red indicator in it

42
Q

How long does it take for a DTM to become positive?

A

3-7 days

43
Q

What causes false positive readings with DTMs?

A

age– not reading it in the correct time frame

44
Q

What type of mycoses does dermatophytes cause?

A

cutaneous mycoses

45
Q

What type of mycoses does sporotrichosis cause

A

cutaneous mycoses that can become systemic

46
Q

What is the dimorphic fungus that is a sporotrichosis?

A

Sporothrix schenckii

47
Q

What type of fungus is Sporothrix schenckii

A

dimorphic fungus

48
Q

Where does Sporothrix schenckii like to live?

A

soil, dead vegetation, and roses

49
Q

What is the typical host of Sporothrix schenckii?

A

Cats

50
Q

What must a patient have in order to become infected with sporotrichosis?

A

and abrasion or puncture/wound

51
Q

How are sporotrichosis diagnosed and what does it look like?

A

Usually diagnosed through histopathology and there will be macrophages with ovid yeast in them

52
Q

What type of mycoses does blastomyces dermatitidis, histoplasma, cryptococcus, and coccidiodes cause?

A

respiratory mycoses that becomes systemic

53
Q

What are the characteristics of Blastomyces dermatitidis?

A

Yeast stain big and blue with broad based budding and are found in wet environments like river valleys

54
Q

What are the characteristics of Histoplasma?

A

Many yeast inside of macrophages and are a associated with bat dropping and can be found in the midwest

55
Q

What are the characteristics of cryptococcus?

A

Yeast have a big thick capsule and are found all throughout the U.S

56
Q

What are the characteristics of coccidioides?

A

Endospores and are found in the southwestern U.S.

57
Q

What is the pathogenesis of dermatitidis, histoplasma, cryptococcus, and coccidiodes?

A

Starts with inhalation of the spore & goes to the lungs
then from the lung it is picked up and taken to the lymph system
from there the spore can then invade the host cells if they normally do that
then the phagocytic cells then carry it around through the lymph & blood to other sites

58
Q

What are the common sites of systemic infection?

A

Bone & Brain
Eyes
Lymphnodes & lungs
Skin

DWT Exam 4 (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions