Mycology Flashcards Preview

Bacteriology > Mycology > Flashcards

Flashcards in Mycology Deck (82)
Loading flashcards...
1

Important component in fungal cytoplasmic membranes that is a target for antifungals

ergosterol

2

Basset hound, cocker spaniels, poodles, and west highland terriers are predisposed to infection with what yeast?

Malassezia

3

Associated with greasy lesions that are malordorous and pruritic

Malassezia pachydermatis

4

Prolonged/excessive antimicrobial therapy can predispose for these infections

Candidiasis
Aspergillosis

5

Associated with moist lesions that can be scabbed; "Bed sores"

candida albicans

6

Which of the cutaneous mycoses can disseminate?

Candida albicans

7

How can you confirm invasion by Candida albican?

microscope exam-->presence of pseudohyphae
(isolation alone isn't enough to confirm diagnosis)

8

Organisms that most commonly cause dermatophytosis

Microsporum spp. (usually M. canis)
Trichophyton spp.

9

What type of cells are infected by Microsporum/Trichophyton

dead skin cells (i.e. stratum corneum, hair, claw)

10

T/F: Geophilic dermatophytosis can be transferred from dog to man

False; can affect both dog and man but they can only get it from soil

11

Infective portion of Microsporum/Trichophyton

arthroconidia

12

Where do horses usually get ring worm

in friction area (i.e. halter area)

13

Pseudomycetomas associated with dermatophytosis are common to which spp.? Prognosis?

Cats
Poor (needs surgery)

14

Onchomycosis?

infection of the nail/claw

15

Best way to diagnose dermatophytosis?

Culture! Most definitive and can be done in-house

16

Dermatophilosis is caused by a _______

gram positive bacteria

17

Dermatophilus zoospores are attracted to what

differing levels of CO2

18

"Paint brush lesions" are typical of infection with

Dermatophilus

19

Diagnostic feature of Dermatophilus?

double rows of spores!

20

Important virulence factors of aspergillus

aflatoxins
gliotoxins--immunosuppressant

21

In dogs, this disease can present as a respiratory disease with bloody discharge and necrosis of sinuses

Aspergillosis

22

Female german sherpherds are predisposed to what

disseminated aspergillosis

23

Does disseminated aspergillosis in dogs have nasal involvement?

not usually

24

This infection in cattle can cause a respiratory tract infection with abortion; there will be TB-like lesions on the placenta

Aspergillosis

25

Horses infected with _____ with usually have guttural pouch infection and keratitis

Aspergillosis

26

Though rare in cats, which breed is more commonly infected with Aspergillosis

Persians

27

Sino-orbital disease in cats is associated with

Aspergillosis

28

A microscopic exam of a sample containing Aspergillosis will show

septate hyphae
dichotomous branching

29

Which diagnostic tool is least useful for aspergillosis?

serology
--many strains
--host may not be making markers

30

Causative agents of Entomophthoramycosis and their primary mode of tramission

Basidiobolus spp. (percutaneous and ingestion)

Conidiobolus spp. (inhalation)

31

Ruminants and small ruminant presenting with a blocked nasal cavity are likely infected with

Conidiobolus

32

This fungus is usually associated with insect bites and rarely disseminates

Basidiobolus

33

When diagnosing Entomophthoramycosis, what should you not do with the sample

refrigerate (they don't like cold)

34

On a microscope, this will present as gram positive branching filaments

Norcardia spp. (Nocardiosis)

35

3 disease forms of Nocardiosis

cutaneous to subcutaneous
pulmonary
systemic

36

A cow that presents with watery milk that contain white/yellow flakes and has an enlarged udder with nodules most likely has

Nocardiosis

37

Why isn't systemic therapy enough to treat nocardiosis

they are intracellular

38

Unique feature of dematiaceous fungi?

contain melanin in cell wall

39

A dog presenting with a tumor-like lesion with draining tracts and granules.
Granules on evaluation are a mixture of necrotic debris and hyphae (with brown pigment). Dx?

Mycetoma

40

Chromoblastomycosis produces what unique feature?

sclerotic bodies

41

Dimorphic fungi are usually ________ dependent

temperature

42

Name the 5 systemic mycoses

Blastomyces
Histoplasma
Crytpococcus
Sporothrix
Coccidioides

43

Most commonly infected host of blastomycosis

dogs

44

An outdoor dog presents with harsh lung sounds, proliferative granulomatous lesions, chronic cough, and weight loss. Radiographs reveal a "snowstorm" appearance to the lungs. Likely Dx?

blastomycosis

45

Best way to diagnose blastomycosis? How will it look?

Microscope exam
broad-based budding yeast (diff-quick)

46

T/F: culture for blastomycosis is easy and can be done in house

False... IT'S VERY DANGEROUS

47

this fungus prefers dark locations and lives in close association with bird and bat excrement

histoplasma

48

Incubation period for histoplasma?

short (12-16 days)

49

Infection of the lower respiratory tract is more likely if this form of histoplasma is inhaled

microconidia (vs. macroconidia)

50

Where does histoplama replicate?

intracellularly ("halo" appearance)

51

A dog presents with weepy, ulcerative lesions, as well as large bowel diarrhea (mucous and blood). Likely Dx?

(based on GI involvement)
histoplasma

52

Why isn't serology very useful for histoplasma?

can get false positive and negatives
also shares antigens with blasto (can be positive for both)

53

Which dimorphic mold is capsulated?

Cryptococcus

54

Cryptococcus favors what form?

yeast

55

Size of the capsule of cryptococcus determines what

if it will stay in the nasal cavity or reach the pulmonary tissue

56

3 important things cryptococcus's capsule does in the host

interferes with leukocyte migration
depletes complement
inhibits t-cell response

57

Which spp. is most susceptible to cryptococcus

Cats

58

A dog presents with skin lesions, fever, and neurological signs. The CNS signs point to a potential cervical lesion, but based on the other clinical signs, it's probably

cryptococcus

59

A use for serology with cryptococcus infections?

monitoring response to treatment (one dilution drop per month of treatment)

60

Sporothrix is usually found where

in moss and decaying matter

61

the mold form of sporothrix produces conidia that usually enter the host _________

cutaneously (but can also be inhaled)

62

Unique feature of Sporothrix?

Both the mold and yeast forms are infective

63

a cat presents with multiple lesions that have shallow ulcers and draining tracts; most notably the lesions are found mostly on mucosal surfaces (i.e. eye, nose, genitalia). Likely cause?

Sporothrix

64

Sporothrix rarely disseminates in what spp.

dogs (usually localized to nose and extremities)

65

A horse presents with lesions on the medial portion of the fetlock and up; the horse has access to the woods; you also are able to palpate the lymph nodes and feel cording of the lymphatics. that's diagnostic for

Sporothrix

66

Coccidioides is endemic to the

southwest

67

What causes activation of Coccidioides in the host

the CO2 content

68

Dissemination with this organism can be rapid (10 days)

Coccidioides

69

Which dog breeds are more susceptible to dissemination with Coccidioides

boxers and doberman pinschers

70

Finding spherules with a KOH wet mount is diagnostic for

Coccidioides

71

This presents as a tumor-like polyp in the nasal cavity and grow so large it can occlude the airway

rhinosporidium

72

What is the only way to diagnose rhinosporidium

microscope (will not grow in lab)

73

Spp. most commonly infected with rhinosporidium

dogs and horses (rarely cats)

74

This organism is associated with slow moving water and has a tropism for well-vascularized tissues

Prototheca

75

T/F: hosts MUST be immuncompromised to be infected with prototheca?

True

76

An aquatic pathogen that can cause cutaneous or intestinal infarctions

Pythium

77

How is phythium different from fungus?

cell wall doesn't contain ergosterol

78

Pythium is attracted to what types of tissue

damaged (plant or mammal)

79

A dog presents with lesions on his extremities and ventral abdomen; he is EXTREMELY pruritic; the owners says the lesions have tripled in size over the past week... Dx?

Pythium

80

Unique features that can be used to ID pythium with a microscope

1) irregular, random hyphae
2) will not stain with H&E
3) eosinophilic cuff

81

Kunkers are associated with infection with what organism?

Phythium insidiosum

82

This organism has broad, relatively nonseptate hyphae and will stain with H&E

Langenidium