Mycology Of CNS

Question 1

Blastomyces dermatitidis

Answer 1

Broad based budding yeast
Distributed in eastern US
Likes water

Question 2

Histioplamsa capsulatum

Answer 2

Yeast, capsulated
Likes nitrogen rich soil, commonly found in bat/bird droppings

Question 3

Cryptococcus neoformans

Answer 3

Capsulated narrow based budding, capsule makes it difficult for the immune system to phagocytize the yeast
Found world wide. C. Gattii found in the soil in west US

Question 4

Coccidioides immitis

Answer 4

Endospore
Certain temperatures and dry climate = desert US

Question 5

Pathogenesis: blasto, histo, cryto

Answer 5

General: inhalation, lower airways - @ higher temps it converts forms - stays in lungs or disseminates via blood/lymph

Question 6

**crypto

Answer 6

Can also cause localized disease in nasal cavity - some strains do not do well at internal body temps

Question 7

Most common signalment for Blastomyces

Answer 7

Dogs>cats
1-5 yrs, large breed with outdoor exposure

Question 8

Signalment for Histoplasmosis

Answer 8

Cats>dogs
Can occur even with indoor cats are exposed to potted plants

Question 9

Signalment of Cryptococcosis

Answer 9

Cats > dogs & horses

Question 10

Signalment for Coccidioimycosis

Answer 10

Dogs > cats> horses > zoo animals
Dogs: young, outdoor exposure

Question 11

Common tissues & organs for Blastomyces

Answer 11

BBELLS to a T

Question 12

Common tissues and organs for histoplasma

Answer 12

Cats : hemolymphatic, BM, LN involvement
Dogs: GIT - ingestion of spores

Question 13

Common tissues and organs for cryptococcosis

Answer 13

1 CNS mycosis - nose/nasal cutaneous

Question 14

Common tissue /organs for coccidioidomycosis

Answer 14

Lung and bone

Question 15

Common clinical signs for Blastomyces

Answer 15

depends on organ system affected
B- neuro abnormalities
E - blindness
L - enlargement (lymphoma)
L - chronic cough
S- nodules, masses w draining tracts, ulceration

Question 16

Common clinical signs for histoplasma

Answer 16

Cats - cytopenia, 2nd IMHA, LA enlargement
Dogs - chronic diarrhea

Question 17

Common clinical signs for cryptococcus

Answer 17

Cats- Roman nose (nasal crypto)
CNS vary dependent on location

Question 18

Common clinical signs for coddidiodis

Answer 18

Dogs - chronic cough, lameness

Question 19

Cryptococcosis:Nasal

Answer 19

Roman nose - swelling on nose & bridge due to inflammation and fugal infection
Ulceration and draining tracts

Question 20

Granulomatous inflammation

Answer 20

Expect to see macrophages as the cell to respond to this kind of inflammation

Question 21

Feline cryptococcus CNS

Answer 21

Acute or chronic neurological signs
Behavior changes (40%)
Gait abnormalities (32%)
Seizures (32%)
Other (<20%)

Question 22

Route of infection for cryptococcus

Answer 22

Local extension from nose, transverse Cribriform plate and straight to the brain
Hematogenous

Question 23

Cutaneous form of cryptococcus

Answer 23

Includes nodules and masses, ulcerated with draining tracts
Naso-cutaneous form - prefers lower temperatures near nose and pinnae of ears

Question 24

Ocular form of cryptococcus

Answer 24

Uveitis - granuloma inside the eye, can progress & lead to blindness

Question 25

Diagnosing histoplasma

Answer 25

Can be seen in blood smear

Question 26

Cytology for diagnosis

Answer 26

Lung: BAL, FNA Lymph node: FNA Skin: draining tract, impression smear

Question 27

Problems with culturing

Answer 27

Dangerous bc fungi is zoonotic Better route is antigen / antibody detection

Question 28

Antigen/antibody detection

Answer 28

Antigen detection is better than measuring antibody

Question 29

Antigen test for what bacteria

Answer 29

Blastomyces and histoplasmosis - galactomannan Will cross test - Blastomyces will test positive for histo and vice versa. Cant tell them apart

Question 30

Samples for antigen testing

Answer 30

Urine - highest sensitivity for Blastomyces/histoplasmosis Serum or CSF for crypto

Question 31

Serum antibody titers

Answer 31

Coccidioides Available for histo & blasto but pair with antigen testing if used Limited number of labs perform these tests

Question 32

Titer

Answer 32

Allow you to know the relative quantitity of antigen or antibody present Highest dilution that will produce a positive test result (highest value)

Question 33

Management for mycolic diseases

Answer 33

Baseline data - CBC, chem, UA, imaging, Ag/Ab titers ± surgical debulking - granulomas, non visual eye Antifungal drugs - azole drugs, Amphotericin B, Flucytosine(crypto) Monitor - drugs aren’t super safe, CBC, chem, UA, imaging, titers, treatment duration is 3-6 months, monitor antigen titers to guide therapy

Question 34

Use for Amphotericin B

Answer 34

Used when rapid response to therapy is needed Good CNS penetration - nephrotoxic

Question 35

Use for ampB + flucytosine

Answer 35

Refractory cryptococcus CNS infections Good CNS penetration Flu: hepatic, drug induced dermatitis, BM toxicity

Question 36

Azole drugs Side effects CNS penetration Use

Answer 36

Hepatoxicity - dont give to cats Only fluconazole & voriconazole have CNS pen Itraconazole - blasto, histo, cocci $$$ Fluconazole - crypto, cocci $ Keto - NA $$ Voriconazole - only in Itra & flu fail $$$$

Question 37

Azoles with good CNS penetration

Answer 37

Fluconazole & voriconazole

Question 38

Azoles go to

Answer 38

Itraconazole - can treat 3/4 blasto, histo, cocci Fluconazole - treats crypto, cocci

Question 39

Surgical treatment for cryptococcus

Answer 39

Nasal flap surgery to remove granuloma - horses, good prognosis

Question 40

Prognosis for Dimorphic fungal infection

Answer 40

Good EXCEPT for CNS involvement Severe pneumonia Canine cryptococcus Disseminated coccidioides Non-nasal crypto in horses 20-30% of cases relapse

Question 41

Fungi that effect dogs more

Answer 41

Blastomyces & coccidiodes

Question 42

Fungi that affect cats more

Answer 42

Histoplasma & cryptococcus

Question 43

Fungi with enlarged LN

Answer 43

Blasto & histo

Question 44

Fungi that present as chronic cough

Answer 44

Blasto and coccidioides