Mycology 6

What type of fungi is isolated from moss, & wood, soil rich in decaying matter and typically found in coastal regions & river valleys?

Sporotrichosis

What type of climate is Sporotrichosis prevalent in?

warm, tropical and subtropical climates

What type of disease does Sporotrichosis cause in humans and animals?

chronic, granulomatous disease of people & animals

What spp of sporothrix is common in the USA?

Sporothrix schenckii

How does Sporothrix schenckii present?

Chronic, granulomatous disease

Nodular or granulomatous lesions withshallow ulcers and draining tracts

What spp of spirothrix was transmitted by cats in Brazil which is more virulent?

Sporothrix brasiliensis

What spp of sporothrix is seen worldwide?

Sporothrix globose

How is Sporotrichosis transmitted?

•Direct inoculation through skin wounds via contact with plants, soil or foreign bodies

T/F Dissemination via inhalation is common

False it is rare

How is Sporotrichosis zoonotic?

bites or scratches

What animals is proven to be the only reservoir and shed high numbers of Sporotrichosis in the feces and urine?

Cats

What are some of the transmissibility factors of cats that can spread Sporotrichosis?

cats are mobile, scratching habits, and fighting behavior facilitates dispersal

What are the THREE clinical forms of Sporotrichosis?

Cutaneous

Lymphocutaneous

Disseminated

How does Sporotrichosis originally present?

single firm nodule that soften, drain purulent exudate

How does Sporotrichosis become Disseminated?

What animals is this seen in?

spread up regional lymphatics infects lymph channels & lymph nodes

nodules develop on distal extremities & ascend the limb following the lymphatics.Nodules may ulcerate & drain a purulent exudate

CATS

How do dogs commonly get infected with Sporotrichosis?

injuries or splinters

(Cutaneous

Lymphocutaneous: seen in hunting dogs)

What are some examples of differentials for Sporotrchosis? (10, name like 4)

pyoderma, phaehyophymycosis, mycobacteriosis, nocardiosis, crypto, neoplasia, foreign body, crypto, immune-mediated disease (pemphigus) or allergies.

How does Sporotrichosis present in cats? (2)

Cutaneous

Lymphocutaneous

Disseminated

What are the THREE things that can lead to multiple lesions of Sporotrichosis in cats?

grooming, self-trauma, & hematogenous dissemination.

How are horses typically infected with Sporotrichosis?

infected thru cutaneous wounds from plant barbs or thorns

Where will you typically find Sporotrichosis in Equine?

LYMPHOCUTANEOUS in horses

THIGH, UPPER FORELEG & CHEST

CORDING OF LYMPHATICS

How do you diagnose Sporotrichosis?

Stain with Diff-Quick or Gram stain

What specimen would you collect from?

draining lesions and aspirates of nodules

T/F In hosts other than cats, organisms are often sparse, so that diagnosis usually requires culture.

True

When are the Sporotrichosis colonies start to grow and how would you describe their look?

Mold colonies are visible in 3 to 5 days. Small, white and flat progressing to wrinkled and leathery

What do you use to treat Sporotrichosis?

Why may this be an issue in cats?

Oral iodides

cats are especially sensitive to iodides

What is another drug that you can use to treat Sporotrichosis?

•Itraconazole (4-6 months; treat 1 month beyond clinical cure)

How long is therapy for treating Sporotrichosis ?

about 7 months

What are some factors to consider when treating for Sporotrichosis?

Overall medical condition, # of affected noncontiguous anatomic regions, & the status of the immune system all influence outcome

What disease does Sporotrichosis cause in humans? (aka its zoonotic)

Gardner's disease

What form of Sporotrichosis is common in man?

cutaneous form

What fungi is associated with soil enriched with bird and bat excrement and who's primary host are humans, dogs, and cats?

Histoplasma capsulatum var. capsulatum

What are the THREE forms of Histoplasmosis?

acute, chronic or systemic

•Ideal environment for Histoplasmosis is rich in chicken, bird or bat ____

feces

Where will you typically see Histoplasmosis?

Central and eastern United States, especially the Ohio and Mississippi River Valleys

T/F Histoplasmosis can contaminated soil will remain infective for years and can survive wide fluctuations in temperature

True

What stage of Histoplasmosis is found in the soil/feces and is the source of infection?

microconidia (2 to 5 um)

Within the lung, the Histoplasmosis transform into ____ that infect ____ ____ and then disseminate to local lymph nodes and the systemic circulation

yeasts

alveolar macrophages

What is cool fun and different about Histoplasmosis?

ONLY US disease cause by fungal intracellular pathogen.

Where does Histoplasmosis go to survive the host's immune system?

Survives within phagolysosome of macrophages

T/F Histoplasmosis is encapsulated

False, it is not

How does Histoplasmosis present on gram stain?

Appears to have thin clear halo surrounding a round or crescent-shaped basophilic cytoplasm.

T/F Histoplasmosis can infect bone marrow and can cause gastrointestinal blood loss

True

What is the most common host of Histoplasmosis?

dogs

Where are the primary sites of infection for Histoplasmosis?

Lungs & thoracic LN

T/F Histoplasmosis can cause a latent infection probably persists for life

True

How would a dog infected with Histoplasmosis present?

Inappetence, weight loss, chronic cough & fever unresponsive to AB common

What is the second most commonly reported mycoses in cats?

Histoplasmosis

How are indoor cats exposed to histoplasmosis?

Exposed thru airborne dust or potting soil

What are the FIVE things that Histoplasmosis can cause in horses?

Localized or Systemic

Pulmonary disease

Anorexia

Diarrhea

Abortion

What are the FOUR things that you can do to identify Histoplasmosis microscopically?

Stain with Diff-Quick

Examine using oil immersion

Small, intracellular yeast (2-5 um)

False appearance of capsule

What are the THREE different types of serology that you can use to diagnose Histoplasmosis?

Agar-gel immunodiffusion

Complement fixation

EIA-enzyme linked immunoassay

T/F Histoplasmosis cultures can be hazardous

True

What are the THREE drugs that you can use to treat Histoplasmosis?

What is the drug of choice?

Itraconazole

Amphotericin B

Fluconazole

Itraconazole

Where in the USA will you typically find Coccidioidomycosis?

arid & semiarid regions of SW USA & similar Mexico, Central & South America

When is Coccidioidomycosis typically most common?

rainy periods are followed by drought - dust storms.

(fall and winter)

What spp of Coccidiodes is a Soil borne organism, associated with respiratory disease, highly infectious, not contagious

and affects man and dogs?

Coccidiodes immitis

Coccidioidomycosis arthroconidia are infectious spherules in host produce ____

endospores

What form of Coccidioidomycosis is most severe w/ extensive granulomatous reactions & tissue damage in skin, bones, joints, meninges, & GI?

Disseminated form

T/F Coccidioidomycosis is highly infectious so less than 10 arthroconidia needed for to cause infection

True

How would you describe Coccidioidomycosis arthroconidia under microscope?

Thick walled, barrel shaped, rectangular arthroconidia

Arthrocondia can persist within the ___ indefinitely

soil

You can see what on histology of Coccidioidomycosis?

Spherules containing endospores

What are THREE things that can contribute to the virulence of Coccidioidomycosis?

Size of the spherule, the size of the replicative burst, & construction of cell wall

What type of disease does Coccidioidomycosis typically cause?

respiratory disease

What will you find on the gross findings of Coccidioidomycosis?

mottling & consolidation of the pulmonary parenchyma; pale masses, nodular lesions w/ necrotic core

What can radiograph revel with regards to Coccidioidomycosis?

local proliferation as well as lysis w/ soft tissue swelling

How do cats present with Coccidioidomycosis?

dermatologic issues including abscess and granulomatous masses

Where do you normally find Coccidioidomycosis with Ruminants & swine?

When is it typically found?

localized to lungs & thoracic lymph nodes.

Found at slaughter.

What random animal. is highly susceptible and develops disseminated form?

Llamas

How do you diagnose Coccidioidomycosis and what would you expect to see?

KOH Wet Mount for spherules

Spherules are round and thick walled with endospores

What drugs can be used for long term therapy for multisystem disease?

Which one can cause nephrotoxicity?

Ketoconazole

Itraconazole

Fluconazole

Amphotericin B

Amphotericin B