Systemic Mycoses Flashcards by Christine Parascandola

Systemic mycoses are Dimorphic, that is, their _______ and _______ phases differ morphologically.

saprophytic, parasitic

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(4) grow as molds in their inanimate habitat.

Coccidioides, Histoplasma, Blastomyces, and Paracoccidioides

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In tissue, Coccidioides produces _______, whereas the others grow as _______
yeasts.

sporangia, budding

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Infection by systemic mycoses is usually by _________. Lesions tend to be __________ to ___________ (_____). Then
dissemination may occur to ?

inhalation, granulomatous, pyogranulomatous, lung, bone, skin, central nervous system, or
abdominal viscera.

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Some mycoses are seen primarily in _____________ animals.

immunocompromised

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Systemic mycoses are ______________.

noncontagious

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Coccidioides, Histoplasma, Blastomyces, and Aspergillus are ____________ mycoses

systemic

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The fungus Coccidioideas immitis and Coccidioideas posadasii cause what disease(s)?

Coccidiodomycosis

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What is the geographical distribution of the fungus Coccidioideas immitis and Coccidioideas posadasii ?

Semi-arid regions in the southwest USA, central and south america

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What are the main hosts of the fungus Coccidioideas immitis and Coccidioideas posadasii ?

dogs, horses, cats, and humans

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What is the usual habitat of the fungus Coccidioideas immitis and Coccidioideas posadasii ?

Soil of low-elevation deserts.

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What are the lesion sites of the fungus Coccidioideas immitis and Coccidioideas posadasii ?

primary lesions in lungs with secondary lesions in bones

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Below is the tissue section from a skin lesion on a dog. A large _________ _________ spherule containing __________ (arrow) surrounded by ___________ tissue.

C. immitis , endospores, pyogranulomatous

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What can be seen below?

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What can be seen below?

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In the case of Coccioides, _____ are most frequently affected, and ____ are occasionally affected. Less
commonly infections are also reported in ?

dogs, horses

cats, swine, sheep, cattle, human and
nonhuman primates.

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Coccidioidomycosis
Adhesins: _______ (for _____ outer wall _________) has affinity for ________ matrix proteins (?)

SOWgp, spherule, glycoprotein, extracellular, laminin, fibronectin, and collagen

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Coccidioidomycosis
___-____________ __ (___): is an enzyme secreted by the endospores of Coccidioides that most likely plays a role in ___________ morphology.

Antibodies (_____ isotype) to ___ are made _____ in the infectious process.

β-Glucosidase 2, endospore, IgM, Bgl2, early

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Coccidioidomycosis
___________ __ (___) is one of several chitinases that are involved
with the ________ of, and _____ of, endospores from the spherule. Antibodies
(____ isotype) to ___ are made ____ in the infectious process (in _________ disease), and are useful diagnostically (detected by the ________ fixation test).

Chitinase 1, Cts1, formation, release, IgG, Cts1, late, disseminated, complement

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Coccidioidomycosis
______ ___,____-______________: Gel (for ?) is located on the _____ of endospores. Gel
elicits a strong ____ lymphocyte response, resulting in elevated levels
of __-interferon followed by protection against __________ disease (activates _________).

β-1,3-glucanosyltransferase, glucan elongating glucanosyltransferase, surface, TH1, γ , disseminated, macrophages

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Coccidioidomycosis

Serine proteases: These enzymes play a role in the stimulation of the ____________ response elicited by Coccidioides. These enzymes digest (3?).

inflammatory, elastin, collagen, and immunoglobulins

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Coccidioidomycosis
Urease: Although its role in virulence is _______, the enzyme urease (_____) elicits a ______ protective immune response following stimulation of ____ lymphocytes (activates ___________).

unknown, Ure, strong, TH1, macrophages

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Coccidioides grows on ______ media over a _____ temperature range.

On Sabouraud’s or blood agar, growth is ______. Over several days, initially ____ _____ colonies develop with sparse _____ mycelium, which gradually becomes more _______. __________ are produced in 5–
7 days.

simple, broad, mycelial, dull gray, aerial, abundant, Arthroconidia

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Describe the pathogenesis of Coccidioidomycosis.

What infection is this patient suffering from?

Coccidioidomycosis

What infection is this patient suffering from?

Coccidioidomycosis

What condition is this patient suffering from?

Coccidioidomycosis

What can be seen in this image below?

How do you diagnose a patient with Coccidiomycosis?

What medications can be used to treat Coccidioidomycosis? Are there any vaccines available to mitigate spread?

Amphotericin B, *Fluconazole, Ketoconazole, Itraconazole* Vaccines are not available.

Histoplasma capsulatum is a ________ fungus existing as a _____ at 25–30 ◦C (________ phase) and as a _____ at 37 ◦C (_______ phase). This fungus has three varieties: ?

dimorphic, mold, saprophytic, yeast, parasitic, H. capsulatum var. capsulatum, H. capsulatum var. duboisii, and H. capsulatum var. farciminosum.

Histoplasmosis is discussed without regard to this varietal distinction; that is, H. capsulatum var. capsulatum and H. capsulatum var. duboisii are regarded as ?

H. capsulatum.

The free living form of H. capsulatum consists of septate hyphae bearing _______ to ________ microconidia 2–4μm in diameter, and “___________” macroconidia, ______-walled spheroidal cells, 8–14 μm in diameter, studded with _____ like projections

spherical, pyriform, tuberculate, thick, finger

List the virulence factors Histoplasmosis possesses.

1. Histoplasmins 2. Adhesins 3. Calcium-binding protein (Cbp) 4. H antigen 5. Iron acquisition 6. M-antigen 7. Melanin 8. Phagolysosome acidification

Histoplasmins, which are used in ________________, are obtained from ________ culture filtrates

immunodiagnosis, mycelial

Adhesins bind to __-_ integrins on the surface of neutrophils, macrophages, dendritic cells. Allow the fungus to enter the cell without triggering an effective _______ ____ and the generation of reactive ____ and ______ intermediates.

β-2, oxidative, burst, oxygen, nitrogen

Calcium-binding protein (Cbp) _____ available ______ within the phagolysosome, this impedes effectiveness of several ________-requiring _______ enzymes.

chelates, calcium, calcium, lysosomal

H antigen was found to be a ____ -__________ that elicited a ____-mediated (protective) immuneresponse to the _____ (_________) phase of H. capsulatum.

β-glucosidase, cell, yeast, parasitic

Iron acquisition by removing iron from host iron-binding proteins (?).

transferrin and lactoferrin

M-antigen was found to be a _________ enzyme, which played a role in the survival of the ________- phase within the phagolysosome.

catalase, yeast

Melanin reduces the toxicity of ________ radicals, __________, and _________ oxygen radicals found within the phagolysosome.

hydroxy, superoxides, singlet

Phagolysosome acidification: Normal phagolysosomes have a pH ____ ___, a pH that optimizes the activity of many of the digestive enzymes found in this environment. H. capsulatum raises the pH of the phagolysosome to _____-_____, thereby reducing the activity of these lysosomal enzymes.How the fungus does this is __________.

<5, 6.0– 6.5, unknown

Histoplasmosis Genetically, variety capsulatum is divided into six classes: class1 and class 2 are found in _______ ______; class 3 is found in ______ and _____ _____; class 4 is found in ______ (________ ____); and class 5 and class 6 are found in ______ patients with _____ immunodeficiency syndrome from ?

North America, Central, South, America, Florida, North America, human, acquired, New York (North America) and Panama (Central America), respectively.

Histoplasmosis is found in the _______ layers, especially in the presence of bird (mainly starlings in North America and chickens in South America) and ______ _______.

topsoil, bat guano

Histoplasmosis Transmission is mostly by ____________ of ________ or _____ fragments, possibly by ______, and, rarely, by _______ infection.

inhalation, microconidia, hyphal, ingestion, wound

The fungus Histoplasma capsulatum var capsulatum cause what disease(s)?

Histoplasmosis

What is the geographical distribution of the fungus Histoplasma capsulatum var capsulatum?

Mississippi and Ohio river valleys, sporadic cases in many other countries worldwide.

What are the main hosts of the fungus Histoplasma capsulatum var capsulatum ?

Dogs, cats, humans

What is the usual habitat of the fungus Histoplasma capsulatum var capsulatum ?

nitrogenous soils-enriched with bird or bat feces.

What are the lesion sites of the fungus Histoplasma capsulatum var capsulatum?

Primary lesions in lungs with dissemination to intestines and other organs.

Histoplasma capsulatum forming large, spherical tuberculate (i.e., spiked) macroconidia

Explain the biology of Histoplasmosis

What condition is this cat suffering from?

How do you diagnose Histoplasmosis?

How do you treat a patient with Histoplasmosis?

Treatment: Ketoconazole, Itraconazole, Fluconazole, Amphotericin B

Blastomyces dermatitidis causes?

Blastomycosis

B. dermatitidis is a ___________ fungus existing as a ____ in the soil (saprophytic stage) and as a ______ in tissue (parasitic stage).

dimorphic, mold, yeast

B. dermatitidis produce conidiophores with _______ or _____ smooth-walled conidia. In tissue or on blood agar at 37 ◦C, the agent is a thick-walled yeast, that reproduces by ____ buds attached by a broad base

spherical, oval, single

Blastomycosis Adhesin termed _____ (for ) binds to phagocytic cells resulting in little generation of reactive _____ and _____ intermediates and downregulates the production of?

Bad1, Blastomyces adhesin 1, oxygen, nitrogen, proinflammatory cytokines.

B. dermatitidis grows on most media at room temperature and 37 ◦C. Colonies develop from within 2 to over 7 days. ______ colonies, formed at ambient temperatures (25–30 ◦C), are _____ ____ to ____ depending on the abundance of ____.

Mold, cottony white, tan, conidia

The fungus Blastomyces dermatidis (teleomorph: Ajellomyces dermatidis) cause what disease(s)?

Blastomycosis

What is the geographical distribution of the fungus Blastomyces dermatidis (teleomorph: Ajellomyces dermatidis) ?

Eastern regions of North America, sporadic cases in Europe, India, and the Middle East.

What are the main hosts of the fungus Blastomyces dermatidis (teleomorph: Ajellomyces dermatidis) ?

Dogs, cats, and humans

What is the usual habitat of the fungus Blastomyces dermatidis (teleomorph: Ajellomyces dermatidis) ?

Acidic soil rich in organic material

What are the lesion sites of the fungus Coccidioideas immitis and Coccidioideas posadasii ?

Primary lesions in lungs with metastases to skin and other organs.

What can be seen here?

Blastomyces dermatidis (teleomorph: Ajellomyces dermatidis)

What can be seen here?

Blastomyces dermatidis (teleomorph: Ajellomyces dermatidis) Oval or pear-shaped conidia

What can be seen here?

Blastomyces dermatidis (teleomorph: Ajellomyces dermatidis) Broad-based buds in tissues.

What can be seen here?

Blastomyces dermatidis (teleomorph: Ajellomyces dermatidis)

Describe what can be seen here?

Blastomycosis Pathogenesis

What fungal infection is this patient suffering from? What can be seen in the images below?

Blastomycosis Fundus photograph from a 5-year-old, neutered male Boxer diagnosed with blastomycosis. Lung, bone and skin lesions were present in addition to the fundic lesion depicted here. (a) At presentation a subretinal granuloma and associated serous retinal detachment affecting approximately 30% of the fundus. (b) After 2 weeks of treatment with systemic itraconazole and systemic prednisone the retinal detachment has flattened and the granuloma has decreased in size. (c) After an additional 6 weeks of therapy the granuloma has further decreased in size and the lesion is becoming a chorioretinal scar.

What condition is this patient suffering from?

Blastomycosis

What condition is this animal suffering from?

Cutaneous lesions in a cat with disseminated blastomycosis that involved the footpads (A), interdigital folds (B), and lips (C)

How do you diagnose Blastomycosis infection?

Diagnostic Culture: SDA Direct examination: Intracellular yeast

How do you treat a Blastomycosis infection?

Treatment Amphotericin B, Ketoconazole, *Itraconazole*

The Blastomycosis dermatidis skin tests lacks _____________ and ___________. Immunofluorescence is used to identify ______ cells in exudates and tissues. The AGID and CFT are not considered to be ________ or _______.

Sensitivity, specificity, yeast, sensitive, specific

Of some 900 species, _____________ _________ is most frequent in animal and human infections.

Aspergillus fumigatus

Aspergillus spp. are _____ consisting of _____ hyphae and characteristic ______ fruiting structures that are borne on __________.

molds, septate, asexual, conidiophores

Conidiophores are _______ branches originating by a ____ cell in the vegetative mycelium and ending in an ___________ vesicle.

hyphal, foot, expanded

The Aspergillus spp. vesicle is covered by a layer or layers of ______ shaped ______, from which chains of _______ conidia (the _______ reproductive units).

flask, phalides, pigmented, asexual

Aspergillus

List the virulence factors of Aspergillus

1. Adhesins 2. Cell Wall PAMP 3. Extracellular Enzymes 4. Iron Acquisition 5. Pigment (Melanin)

Aspergilli grow on all common _____________ Aspergilli thrive in the _____________. Some are highly resistant to _______ and _________.

laboratory, environment, heat, drying

Aspergilli are present in?, and secondarily in??

soil, vegetation, feed, air and water and objects exposed to them

Aspergillosis is acquired from ?

environmental sources, generally by inhalation or ingestion.

Aspergillus fumigatus Pathogenesis

1. Aspergillosis causes ____________ ___________ in newly hatched chicks. Transmission occurs via inhalation of ______ from _____. Can also be introduced to _____. You can reduce transmission by ? 2. Aspergillosis causes _____________ and _____ _____________ mainly in young birds. Occurrence is __________. 3. Generalized aspergillosis affects?

1. brooder pneumona, aerosols, spores, eggs, fumigating hatching incubators. 2. pneumonia, air sacculittis, sporadic 3. Captive birds (penguins) that are stressed.

Dog nasal aspergillosis affects _________, _________ dogs, and results in __________ nasal ____________ (often ___________) --> damage in the nasal _____________ and ____________. Otitis externa, part of normal flora.

young, urban, chronic, discharge, unilateral, mucosa, turbinates,

These dogs are suffering from what fungal infection?

Aspergillosis

These kittens are suffering from what fungal infection? What can you see grossly?

See below

This animal is suffering from what fungal infection? What do you see in the images below?

See below

Bovine abortion outbreaks caused by Aspergillosis spp are often related to ________ _______. In pregnant cattle, ________ gestation combined with ____-quality feed and ____ weather and ______ add up to severe challenge.

moldy fodder, advanced, low, poor, housing

Aspergillosis in chicken flocks commonly coincides with the use of _______ ________ litter, ______ husbandry. _______ aspects are usually recognizable in outbreaks.

heavily, contaminated, poor, Stress

Canine nasal aspergillosis occurs especially in _______ dogs of _______ breeds.

young, dolichocephalic

In the case of Aspergillosis spp, some ___-lymphocyte deficiency may exist

In keratomycosis of horses, the frequent history of topical ___________ and _____ treatment suggests immunosuppression and impaired _________ resistance. * Cell-mediated immunity is believed to be the major factor in limiting the ___________ of infection. * _________ procedures are not available.

antibacterial, steroid, colonization, dissemination, Immunization

Aspergillosis spp. Diagnosis/Treatment

Diagnosis = DIECP * Direct Examination: Hyphae, fruiting heads, and conidia * Culture * Immunodiffusion test kit * ELISA * PCR Treatment: * The nasal form in dogs is treated topically with instillation of clotrimazole or enilconazole into the nasal passages and sinuses. Itraconazole (given orally) has been successfully used to treat nasal aspergillosis when topical treatment is not possible. * Itraconazole has been beneficial in treating disseminated aspergillosis.

Pneumocystis carinii is an __________ pathogen capable of causing severe ___________ in ____________ individuals. Most cases in domestic animals have occurred in ?

opportunist, pneumonia, immunocompromised, horses and dogs

What fungus is pictured below?

Pneumocystis carinii

What fungus is pictured below? What can be seen in each image?

Pneumocystis carinii Left image: Wright-stained, large clusters of EC organisms consistent with ameboid spores (trophic forms) and cysts of Pneumocystis *green aroww*). Right image: Grocott-stained image. Dark spot = spherical cyst of Pneumocystis. Erythrocytes are light blue with this stain.

1. List the fungi that cause cause mycotic bovine abortion and gastrointestinal infections, marked by ulcerative lesions and mesenteric lymphadenitis, in ruminants, swine, and dogs, as well as respiratory and hematogenous infections affecting various viscera and the central nervous system

Rhizopus spp., Rhizomucor spp., Absidia spp., Mucor spp.,and Mortierella spp.

Rhizopus spp

Mucor spp.

Absidia spp.

Mortierella spp