Yeasts Flashcards

1
Q

Under a microscope, you see Hyphal structures. What is the causative agent? How would you describe the appearance?

A
  1. Mold
  2. “fuzzy”/wooly appearance
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2
Q

Under a microscope, you see Single cell/budding structures. What is the causative agent? How would you describe the appearance?

A
  1. Yeast
  2. “bacteria like”
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3
Q

List the representative yeasts.

A

Cryptococcus neoformans
Malassezia pachydermatis
Candida albicans

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4
Q

Cryptococcus neoformans is associated with ________ lesions affecting _______ membranes. Examples?

A

ulcerative, mucous
Respiratory tract (including nasal sinuses), central nervous system (meninges), eyes (chorioretinitis)

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5
Q

______ are more severely affected by Cryptococcus neoformans, resulting systemic mycosis.

A

Cats

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6
Q

How does Cryptococcus neoformans affect cattle?

A
  • Cows (mastitis)
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7
Q

How does Cryptococcus neoformans affect horses?

A
  • Horse (endometritis and abortion)
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8
Q

List all the species Cryptococcus neoformans affects?

A

Dogs, ferrets, sheep, goats, llamas, parrots, elk, horses, cats, cows, and humans

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9
Q

How does Cryptococcus neoformans affect humans?

A

(opportunistic pathogen/ immunocompromised patients)

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10
Q
A

Cryptococcus neoformans

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11
Q
A

Cryptococcus neoformans

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12
Q

Cryptococcus neoformans
* Characteristics
* ________ cells
* ____________ fungus
* Contains ____ acids- _____ complement proteins to degradation
* Produces phospholipase which is involved in the membrane _______ in the host cells
* Produces _________, a powerful antioxidant, resist enzyme ________, ______, allows _______ absorption

A

Spherical, Monomorphic, sialic, direct, disruption, melanin, degradation, radiation, nutrient

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13
Q

What is a major virulence factor of Cryptococcus neoformans? What is its purpose?

A
  • It has a very thick capsule
    Capsule, a major virulence factor. Prevents antibody phagocytosis, stimulate T regulatory cells,
    inactivate the alternative complement pathway activation
    Underline characteristics are associated with its pathogenesis in infected animals
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14
Q

Cryptococcus neoformans
* Growth characteristics
- _____ temperature to ___°C
- encapsulation is optimal in _________ agar plates, ___°C, ___% CO2
- produces _______ pigmented colonies
- four antigenic types: ?

A

room, 37, chocolate, 37, 5, melanin, A, B, C, D.

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15
Q

Cryptococcus neoformans
* Ecology
- lives in surface ____ and ___
- present in dried _____ feces up to _____ year (rich in _________)

A

dust, dirt, pigeon, one, creatinine

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16
Q

Cryptococcus neoformans
* Transmission

A
  • respiratory, rarely percutaneous, non- contagiuos
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17
Q

What can be seen in the image below?

A
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18
Q

What can be seen in the image below?

A
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19
Q

Describe the pathogenesis of Cryptococcus neoformanns in the CNS.

A

Meningitis relatively asymptomatic), encephalitis, granuloma

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20
Q

Describe the pathogenesis of Cryptococcus neoformanns in the Pulmonary System

A

Bilateral, miliary lesions, lobar pneumonia

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21
Q

Describe the pathogenesis of Cryptococcus neoformanns in the cutaneous system

A

Traumatic implantation, ulcerative papules in skin
Nodules, granulomas, or ulcers in mucocutaneous tissue
Manifestation of systemic disease

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22
Q

What is the primary site of Cryptococcus neoformans infection in cats?

A
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23
Q

What is the primary site of Cryptococcus neoformans infection in dogs?

A
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24
Q

What is the primary site of Cryptococcus neoformans infection in horses?

A
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25
Q

What is the primary site of Cryptococcus neoformans infection in cattle?

A
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26
Q

What is the primary site of Cryptococcus neoformans infection in koala?

A
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27
Q
A

Cryptococcus neoformans - cat

28
Q
A

Cryptococcus neoformans - cat

29
Q
A

Cryptococcus neoformans - skin

30
Q
A

Cryptococcus neoformans - lung

31
Q
A

Cryptococcus neoformans - horse

32
Q
A

Cryptococcus neoformans - dog

33
Q

Cryptococcus neoformans
Immunity
- Serology: Detection of antibodies to ______
- _____ mediated immunity ( ________ activation)
- _____ cells

A

capsule, Cell, macrophage, NK

34
Q

Cryptococcus neoformans
Laboratory Diagnosis
- ______ examination using _____ ink, from _______, _____________ washes, cerebro-spinal fluids
- Histopathology, _____ and _____ staining
- _________, ______ agar and _____ at room temperature or 30°C

A

Direct, india, exudates, tracheobronchial, Wright, Giemsa, Culture, blood, SDA

35
Q

Cryptococcus neoformans
Treatment?
Control?

A
  • Fluconazole, Itraconazole, 5- fluorocytosine

-Disinfect surfaces (facilities)

36
Q

Malassezia pachydermatis
* Characteristics
- ____, ________ yeast
- ________ are not usually observed
- Culture in ____ agar, colonies with ______ tint seen on the surface
- Range of temperature incubation: ___ to ___°C
- ______ or _______

A

Oval, budding, Filaments, blood, greenish, 25, 41, Aerobic, microaerophilic

37
Q

Malassezia pachydermatitis produces enzymes including?
How many biotypes does Malassezia pachydermatitis have? Name them.

A

proteinase, chondroitin sulfatase, hyaluronidase,
and phospholipase

  • Four genetic biotypes: A, B, C, D.
38
Q

What can be seen in this image?

A

Malassezia pachydermatidis

39
Q

Malassezia pachydermatis normally lives on ___ and ____ _______ of dogs, cats, ferrets, ruminants, horses.

A

skin, ear canal

40
Q

Malassezia pachydermatitis is associated with _____ ________ and _______.

A

otitis externa, dermatitis

41
Q

What are the disease contributing factors that lead to Malassezia Pachydermatitis?

A
  • Immune-mediated hypersensitivity and immunosuppression are
    contributing disease factors
42
Q

How is Malassezia pachydermatis transmitted? Which dog breeds are more susceptible?

A

Transmission
- Opportunistic fungus
- Associated to other skin diseases
- Dog breeds more susceptible: Australian silky terriers, basset hounds,
cocker spaniels, dachshunds, poodles, West highland white terriers.

43
Q

Malassezia pachydermatis: Laboratory diagnosis
- _____ examination, ____-tipped swabs rolled on glass slides and stained with _____ and _____. You will see _____ with characteristic morphology of “ ______-shaped or “ _____ print”.
- Cotton-tipped swabs streaked on ____ at ____°C
- _____

A

Direct, cotton, Wright’s, Giemsa, yeast, bottled, shoe, SAD, 37, PCR

44
Q

How is a case of Malassezia pachydermatis treated?

A
  • Nystatin, clotrimazole, miconazole, ketoconazole, itraconazole

NICKM

45
Q

What can be seen in the image below?

A

Malassezia pachydermatis

46
Q

What can be seen in the image below?

A

Malassezia pachydermatis

47
Q

What can be seen in the image below?

A

Malasseiza dermatitis associated with allergic dermatitis

48
Q

Candida albicans (___________) is apart of ______ flora of mucous membranes of most ________ and ______

A

Candidiasis, normal, mammals, birds

49
Q

How many species of Candida albicans exist? How many cause disease?

A

More than 200 species, few are associated with disease

50
Q

Which species are more susceptible to infection by Candida albicans?

A

Immunocompromised animals (humans) are more susceptible & Overuse of antibiotics, steroids and hormones.

51
Q

Candida albicans
* Oval budding yeast cells sprout _______ _____ that develop into _____-branching mycelium
* ___________
* Chlamydospore is a _____ walled _____ attached to the mycelium (in _____ only)
* _____ sero-groups are recognized: ?

A

germ tubes, septate, Blastoconidia, thick, sphere, vitro, Two, A and B

52
Q

What can be seen in the image below?

A
53
Q

What can be seen in the image below?

A

Pseudomycelium + blastoconidia

54
Q

What are the cellular products produced by Candida albicans? What are their functions?

A
  • Cellular products
  • Adhesin: adhesion to extracellular matrix proteins
  • Proteases and neuraminidases: promote tissue invasion and
    adherence to host cells
55
Q

Candida albicans
* Growth characteristics
- ________, ___ to ____°C, _____

A

Aerobic, 25, 30, SDA

56
Q

Candida albicans
* Ecology
- Present in ____________ areas, ____ and _____ tracts of mammals and birds

A

mucocutaneous, GI, genital

57
Q

How is Candida albicans transmitted?

A
  • Transmission
  • Endogenous infection, C. albicans is a commensal micro-organism
  • Hematogenous spread Systemic infections
58
Q
  1. List the characteristics of Candida albicans that help it carry out its disease pathogenesis.
  2. Candida albicans pathogenesis:
    - Affects _______ surfaces of ____ tract from _____ to ____, ______ to ______ or ____ plaques with areas of _______ and ______
  3. What other areas are affected?
  4. Septicemic infections –> ?
A
  1. See below:
    - Adhesin
    - Cell wall glycoproteins –> Endotoxins
    - Proteases and phospholipases –> virulence factors
  2. mucous, GI, mouth, stomach, whitish, yellow, gray, ulceration, inflammation
  3. Genital tract, skin, claws are affected.
  4. Respiratory and intestinal
59
Q

Candida albicans
Disease effects which species?

A

Birds, swine, equine, cattle, dogs, and cats

60
Q

Candida albicans infection effects what part of the body in birds, swine, and equine?

A

GI tract

61
Q

Candida albicans infection causes what conditions in cattle?

A

Pneumonic, enteric, mastitis, and systemic candidiasis

62
Q

Candida albicans infection causes what conditions in dogs and cats?

A

non-healing ulcerative lesions on the oral,
upper respiratory mucosae, GI mucosae, and genitourinary tract

63
Q

How would you diagnose Candida albicans in a patient?

A
  • Laboratory diagnosis
  • Blastoconidia, pseudohyphae observation
  • Stains: Gram, Wright-Giemsa, periodic acid Shifft, Gomori metheneamine silver
64
Q

How would you treat a patient suffering from Candida albicans ?

A
65
Q
A

Candida albicans

66
Q

How many species of Candida albicans exist? How many cause disease?

A

More than 200 species, few are associated with disease

67
Q

Which species are more susceptible to infection by Candida albicans?

A

Immunocompromised animals (humans) are more susceptible & Overuse of antibiotics, steroids and hormones.