Brainscape's Knowledge GenomeTM

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


See full index

Bacteriology > Mycoses > Flashcards

Mycoses Flashcards

1
Q

Sporangiospore

A

fungal spore formed by asexual reproduction. formed within a sporangium on an aerial hyphae called a sporangiophore

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

Conidia

A

fungal spore formed by asexual reproduction. formed on conidiophore

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

Zygospore

A

fungal spore from sexual reproduction. Develops in thick-walled zygosporangium, formed from the fusion of side projections of two compatible hyphae

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

Geophilic dermatophyte

A

dermatophyte that inhabits soil in association with decomposing keratinous material

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

Zoophilic dermatophyte

A

obligate pathogen in animals

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

Anthropophilic dermatophyte

A

obligate pathogen of humans

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

Dermatophyte important causal agents

A

Microsporum, Trichosporum, Epidermophyton

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

Microsporum general characteristics

A

invades hair and skin
thick-walled, multi-septated macroconidia
microconidia are stalked, clavate or arranged singly along hyphae
M. canis most common in domestic animals

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

Trichophyton general characteristics

A

Invades hair, skin, nails, horns, claws

Thin walled and smooth macroconidia, cylindrical to cigar shaped. Typically more severe than Microsporum infections

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

Dermatophytosis clinical signs

A

alopecia, erythema, scaling, crusting, annular-ringed lesions, vesicles or papules

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

Dermatophytosis transmission

A
  1. Arthrospores shed by infected animals are viable in the environment (months to years)
  2. direct contact with infected animal
  3. exposure to arthrospores in the environment/fomites
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Dermatophytosis pathogenesis

A

Dermatophytes –> enter stratum corneum –> release proteases –> cause inflammation –> movement away from site of infection to nearby follicle –> central healing causes ringed lesion

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

Canine ringworm genuses

A

M. canis, M. gypseum, T. erinaceid, T. mentagrophytes

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

Canine ringworm lesions

A

brittle hair, dry and scaly skin, crusts and scabs

Kerion –> specific lesion due to T. mentagrophytes (intense inflammation, swelling, ulceration, prurulent exudate)

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

Canine predispositions to ringworm

A

Compulsive diggers (gypseum), good rat catchers (mentagrophytes), avid hedgehod worries (erinaceid)

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

Feline ringworm

A

M. canis –> main genus, cats are reservoir
Often asymptomatic (public health risk)
Lesions: circular areas of stubbed hair, alopecia, mild scaling and folliculitis at the head
Most common in kittens with immature immune systems and adults with immune deficiencies.

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

Feline otitis

A

persistent waxy, ceruminous, otic discharge caused by M. canis

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

Bovine ringworm

A

Trichophyton verrucosum.
Calves are more susceptible and incidence is higher in winter.
Lesions: circular, scattered, accompanied by skin scaling and alopecia, large plaques may develop with the formation of thick scabs and crusts, severe inflammation, pruritus (secondary bacT infections?)
Spontaneous resolution

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

Porcine ringworm

A

Microsporum nanum
Common disease, affects large breeds. Higher incidence with high density and humidity, poor sanitation
Lesions: circular, roughened, mildly inflamed. anywhere on body

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

Equine ringworm

A

T. equinum, M. gypseum
Lesions: multiple, dry, scaly, raised lesions on any body part. Inflammation and exudates cause hair to mat together and enlarged lesions create a moth-eaten appearance
Infections often become chronic and subclinical and recur under stress

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

Avian ringworm/favus/white comb

A

M. gallinae
Lesions: white patches on the comb of infected male birds
Occasionally, disease spreads into the feathers

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

Wood’s lamp

A

dermatophytosis diagnostic technique - 50-60% of M. canis infections test positive under UV light. Use fluorescing hairs for sampling

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

Direct microscopic exam for dermatophytosis

A

examine hairs from lesions/scales. Use 10-20% KOH. Fine hyaline septate hyphae in keratin scales and in hair shafts. Arthroconidia see on hair.

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

Dermatophyte Test Medium (DTM)

A

Growth with red slant before 10 days - dermatophyte
Growth with yellow slant that turns red after 10 days - non dermatophyte.
Medium provides peptones for protein, antibiotics, dextrose sugar, cyclohexamide to inhibit sapprophytes
Incubate at 25-30 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

M. canis on culture

A

spreading whitish and cottony surface. Golden-yellow reverse pigment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Physiological tests for dermatophytes

A

temperature tolerance, urease production, in vitro hair perforation test for Trichophyton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Treatment for dermatophytes

A

remove/kill fungus from skin/hair (clip, shampoos, dips, sprays, topical antifungals). Systemic therapy: azoles
Treat until 3 negative cultures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

control/prevention for dermatophytes

A

clean up environment and fomite sources (vacuum, wash bedding, etc.) use 10% bleach solution. Vaccination is effective for bovine ringworm.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Zoonotic dermatophytes

A

M. canis and T. verrucosum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Dermatomycoses important causal agents

A

Malassezia, trichosporon, geotrichum candidum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Malassezia

A

M. pachydermatis

lipophilic yeast, opportunistic pathogen (part of normal microbiome on the skin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Otitis externa (malassezia)

A

clinical signs: head shaking, pruritus, bad odour, chronic otitis
Diagnosis: otoscopic exam of ear canal, cytology for bacteria, yeast and mites
Treatment: treat predisposing factors, topical antifungals and systemic antimicrobials

33
Q

Seborrheic dermatitis (definition + CS)

A

superficial dermatitis as a regional disease affecting ventral abdomen, face, feet, neck. perineum, leg folds or generalized disorder
Clinical signs: face rubbing, foot licking, erythematous skin, scaly skin, alopecia, hyperpigmentation, lichenification

34
Q

Seborrheic dermatitis predispositions

A

breed: poodles, spaniels, chihuahuas, german shepherds, boxers, basset hounds
others: allergies, seborrhea

35
Q

Seborrheic dermatitis diagnosis, treatment

A

history of poor response to therapies, demonstration of yeast on skin scrapes (rule-out system). Most useful is cytology of affected areas looking for slightly elongated, oval, broad-based yeast
Treatment: remove predisposing factors, shampoo/creams/dips with selenium sulfide/ketoconazole, oral ketoconazole

36
Q

Trichosporon

A

causes nasal mass in cats. Treatment is to remove the mass surgically and follow up with oral ketoconazole

37
Q

Geotrichum candidum

A

more found in exotic animals. Often isolated from feces of healthy/clinically normal animals. Causes cutaneous lesions, nodular, well-circumscribed dermo-epidermal masses

38
Q

subcutaneous mycoses general characteristics

A

infections of deep skin, muscle, bone or CT. Associated with injured tissues.
Etiologic agents: soil/decaying vegetation, dematiaceous or hyaline molds and dimoprhic fungi
infections are chronic

39
Q

Important causative agents of subcutaneous mycoses

A

Sporothrix schenckii, histoplasma capsulatum var. farciminosum, dermatiaceous fungi

40
Q

Sporotrichosis characteristics

A

dimorphic, dermatiaceous.
yeast at 37 degrees - cigar shaped, pleiomorphic budding yeast.
mold at 25 degrees - thin septate hyphae with conidia in a rosette-cluster
found in soil, vegetation, peat moss and wood
Conidia enter the skin through puncture wounds from thorns or bites

41
Q

Sporotrichosis geography

A

most common in in tropical and subtropical america

42
Q

Sporotrichosis lesions

A

subcutaneous nodules that ulcerate and heal. lesions are not painful or pruritic. Disease may follow lymphatic vessels

43
Q

Sporotrichosis CS in dogs

A

Cutaneous: localized, multicentric
Lymphocutaneous: nodules along lymphatics
Disseminated: rare, possibly fatal

44
Q

Sporotrichosis pathogenesis

A

conidia or mycelia enter through broken skin –> change from mycelial form to yeast or parasitic form –> virulence factors (thermotolerance, acid phosphatases, proteinases) –> lymphocutaneous manifestation –> infection spreads along lymphatics

45
Q

Diagnosing sporotrichosis with LM

A

Under LM: look for yeast (in macrophages). Cat lesions tend to have more yeast

46
Q

Diagnosing sporotrichosis with culture

A

mold colonies are cream coloured, wrinkled and leathery. Will turn black/grey with age.
Yeast colonies are soft and white to cream coloured

47
Q

Sporotrichosis treatment

A

Iodide (not for cats), azoles, Itraconazole for cats

48
Q

Sporotricosis zoonosis

A

most human cases occur through shedding from cats (scratch, bite).
Prophylaxis: care in handling rote wood, plant material and infected animals

49
Q

Epizootic lymphangitis

A

Histoplasma capsulatum var. farciminosum
Dimorphic fungus.
Yeast: pear shaped, double contoured budding yeast in macrophages/neutrophils
Can be isolated from soil enriched with bird or bat feces
Infection acquired by wound infection or transmission by blood sucking insects

50
Q

Epizootic lymphangitis host

A

equids

51
Q

Epizootic lymphangitis lesions

A

granulomatous, nodular lesions with a tendency to ulcerate in skin, subcutaneous tissue, along lymph vessels

52
Q

Chromoblastomycosis

A

chronic fungal infection in cats and humans. Dermatiaceous fungi form thick walled-muriform cells (sclerotic bodies).
CS: firm, protuberant, warty, ulcerative nodules (on feet and legs)

53
Q

Eumycotic mycetoma

A

Limited to one area of the body.
CS: swelling, fistulas, grains or granules in exudate. SubQ swellings with draining tracts, may resemble chronic abscess.
Chronic mycetoma – fistulous tumour
may cause osteomyelitis

54
Q

Phaeohyphomycosis

A

saprophytic, pigmented fungi that appear in lesions as dematiacous, septate hyphal forms (no granules).
Found in dogs and cats
CS: pustules, abscesses, granulomas, shallow ulcerated or open lesions

55
Q

Bovine nasal granuloma

A

Granulomatous swellings in the nasal cavity and trachea of cattle.
CS: dyspnea, inspiratory stridor, nasal discharge. Pink-white polyps visible on endoscopy

56
Q

Bovine nasal granuloma diagnosis

A

direct exam of crushed polyp – dematiaceous fungi

culture – white colonies that become olive green, brown or black with dark reverse pigment

57
Q

systemic mycoses primary SOI

A

lungs

58
Q

systemic mycoses important causative agents

A

Blastomyces dermatitidis (dimorphic), coccidioides immitis (dimorphic), histoplasma capsulatum var. capsulatum (dimorphic), cryptococcus neoformans (yeast)

59
Q

Blastomycosis

A

Blastomyces dermatitidis.
Affects cats, dogs, humans
Moves from lungs to skin, eyes and bones

60
Q

Blastomycosis lesions

A

few to numerous, variable sized, irregular, firm, grey to yellow areas of pulmonary consolidation and nodules in lungs and thoracic lymph nodes
Cutaneous lwesions – single or multiple papules or chronic draining, nodular pyogranulomas

61
Q

Blastomycosis pathogenesis

A

Aerosolized mycelial fragments or spores from the environment are inhaled. These are deposited in alveoli of a susceptible host. The mature yeast develop and grow intracellularly as large budding yeast. May spread from the lungs via lymph/blood vessels

62
Q

Blastomycosis distribution

A

Highly endemic in North America –> Ohio, missouri, tennessee, mississippi river valleys, st. lawrence river area, great lakes

63
Q

Blastomycosis clinical signs

A

coughing, dyspnea, dry and harsh lung sounds, anorexia, depression, lameness, lymphadenopathy, skin lesions (predominant in cats), ocular lesions

64
Q

Blastomycosis diagnosis

A

clinical signs, history.
Samples: tissues, tracheal wash, lymph node biopsy, cutaneous lesion exudate or biopsy
Microscopy: spherical, thick walled, large, broad-based budding yeast
Culture: mold culture is severe biohazard

65
Q

Blastomycosis treatment

A

Itraconazole for dogs, amphotericin B for chronic/tough cases

66
Q

Blastomycosis zoonosis

A

zoonotic transmission is uncommon but can happen from contaminated knives or dog bites. PPE important!

67
Q

Coccidiomycosis (San Joaquin Valley Fever)

A

Coccidioides immitis.
Dust-borne, not contagious
Humans, dogs, llamas affected
Primarily a chronic respiratory disease can spread to eyes, bones and joints
Not zoonotic, but can mycelial phase can form on bandages of draining lesions

68
Q

Coccidiomycosis pathogenesis

A

Arthroconidia in the environment mature into mycelia which fragment into arthrospores. Infection is via inhalation of arthrospore which causes transition into a spherule. spherule matures with production and release of endospores. Endospores will travel in lymph/blood

69
Q

Coccidiomycosis distribution

A

Infections are in semi-arid regions of the SW USA (arizona, california, new mexico, texas, utah, nevada) and sikmilar areas of central and south america

70
Q

Coccidiomycosis clinical signs

A

anorexia, cough, weight loss, lameness, abscesses, draining tracts, lymphadenopathy, meningitis

71
Q

Coccidiomycosis diagnosis

A

CS and history
Samples - draining lesions and biopsies or fine-needle aspirate of infected tissue (ook for classic spherules
Culture - mycelial form very hard to handle. Mold have hyaline hyphae and alternating, barrel-shaped arthroconidia

72
Q

Coccidiomycosis treatment

A

long term treatment (8-12 weeks) with azoles, amphotericin B if needed

73
Q

Histoplasmosis

A

Histoplasma capsulatum var. capsulatum
chronic, non-contagious, disseminated, granulomatous disease of humans and animals
mainly in dogs and cats under 4

74
Q

Histoplasmosis lesions

A

enlarged liver, spleen and mesenteric lymph nodes. Ascites, yellow-white variable-sized, granulomatous nodules in the lungs enlarged bronchial LNs, foci of granulomatous inflammation on liver, myocardium and SI

75
Q

Histoplasmosis pathogenesis

A

inhalation or ingestion of microconidia or hyphal fragment from environment, conversion to yeast in vivo, yeast replicate, may spread via lymph/blood to spleen, bone marrow

76
Q

Histoplasmosis distribution

A

humid environments with highly nitrogenous soils (contaminated with bird/bat shit).
High risk areas: bat caves, old chicken houses
Regions: tennessee, ohio, mississippi, missouri, st lawrence river area

77
Q

Histoplasmosis clinical signs

A

pulmonary infection predominant, chronic disease (inappetance, weight loss, fever), enlarged LNs, anemia, GI problems in dogs

78
Q

Histoplasmosis diagnosis

A

clinical signs and history
samples: buffy coat smear, LN aspirate, rectal scraping, biopsies, bone marrow aspirate. Yeast are small in macrophages, basophilic center and clear halo
Cultures are a severe biohazard

79
Q

Histoplasmosis treatment

A

long-term treatment (4-6 months min) with azoles. Amphotericin in combination with oral azole for severe cases.

Bacteriology (8 decks)

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