Bacteriology - Mycoses 2

Question 1

Dermatophyte infectious agents

Answer 1

Microsporum spp
Trichophyton spp

Question 2

Dermatophytes features

Answer 2

Ringworm
Animals, birds, humans
Keritinized structures
Zoophilic
Geophysical
Anthropophilic

Question 3

What effects Dermatophytosis pathogenesis?

Answer 3

Innate immunity, lack of trauma
Predisposing factors

Question 4

Dermatophytosis clinical signs

Answer 4

Hair loss, scales, crusts, red skin (erythema), puritis (variable), papules/pustules/kerion

Question 5

Dermatophytosis diagnosis (4)

Answer 5

Woods lamp
Cytology
Fungal culture
Histopathology

Question 6

Woods lamp

Answer 6

40%, topical, scales
Not reliable

Question 7

Wet mount cytology - derm

Answer 7

Superficial scraping, arthroconidia (in animal tissue)

Question 8

When would you sample Dermatophytosis with a toothbrush?

Answer 8

Testing possible carrier animals not currently presenting with lesions

Question 9

Dermatophytosis cultures

Answer 9

DTM - change to red
RSM - change to blue
3-7 days

Question 10

Tape preparation results for macroconidia

Answer 10

M. Canis - common in dogs, cats as carriers
M. Gypseum - some dogs, less common
M. Nanum - pigs

Question 11

Tape preparation findings for Trichophyton

Answer 11

T. Mentagrophytes - hyphae, common in agriculture
T. Verrucosum

Question 12

What circumstances would warrant a histopath for Dermatophytosis?

Answer 12

Very severe infections
Cases that aren’t responding to current treatment

Question 13

Sporothrix schenckii

Answer 13

Starts as cutaneous infection
Can become systemic

Question 14

Sporotrichosis

Answer 14

Dimorphism fungus
Soil, roses, cats
Requires tissue damage
Cutaneous, lymphocutaneous, disseminated

Question 15

What cytologic diagnosis is expected in sporotrichosis?

Answer 15

Macrophage filled with ovoid yeast

Question 16

What species fall under Respiratory -> systematic infection?

Answer 16

Blastomyces
Histoplasma
Cryptococcus
Coccidioides

Question 17

Etiology/morph of blastomyces

Answer 17

Enviro - fruiting body
Vito - broad based budding yeast

Question 18

Etiology/morph of histoplasma

Answer 18

Enviro - fruiting bodies
Vito - tiny yeast, reliably found inside macrophages

Question 19

Etiology/morph of cryptococcus

Answer 19

Narrow based budding yeast within capsule
-anti phagocytosis function

Question 20

Etiology/morph of coccidioides

Answer 20

Enviro - hyphae
Vivo - endospore

Question 21

BELLS in resp-systemic mycoses

Answer 21

Bones, brain
Eyes
Lymph
Lung
Skin

Question 22

Bells - bones

Answer 22

Blastocyst, histoplasma & coccidiosis
Osteomyelitis, limping, arthritis, swelling

Question 23

Bells - brain

Answer 23

CNS signs, depends on final destination of fungi
Ataxia, stumbling

Question 24

Bells - eyes

Answer 24

Swelling, leakage, blindness

Question 25

Bells - lymph

Answer 25

Lymphadomopathy, multi lymph swelling

Question 26

Bells - lungs

Answer 26

Exercise intolerance, resp rate, panting
Diffuse lung damage, fungal circulation

Question 27

Bells - skin

Answer 27

Severe patches, lesions, necrosis

Question 28

Diagnosis of resp - systemic

Answer 28

Blood smear, cytology, histopath
Serum, urine, CSF
Avoid cultures