Systemic Mycoses

Question 1

Systemic Mycoses

Transmitted by inhalation of____ from_____ environments; fungi isolated from____ soil or in soil mixed with_____

Answer 1

conidia

humid

acidic

guano

Question 2

SYSTEMIC MYCOSES

• Fungal infections that invade the____
• Predominantly affect_____ hosts
•_____ mycoses can cause disease in healthy individuals.
• Profound impact on human health

Answer 2

deep organs (endemic and opportunistic fungal pathogens)

immunocompromised hosts

Endemic

Question 3

SYSTEMIC MYCOSES

• Increasing in morbidity and mortality due to increase in (4)

• Fungal pathogens have acquired the ability to overcome the____

Answer 3

• susceptible hosts
• international travel
• migration
• human encroachment on the environment

lung innate immune responses

Question 4

Blastomycosis

Answer 4

Blastomyces dermatitidis ( species
complex)

Question 5

Coccidioidomycosis

Answer 5

Coccidioides immitis/ C. posadasii

Question 6

Histoplasmosis

Answer 6

Histoplasma capsulatum

Question 7

Paracoccidioidomycosis

Answer 7

Paracoccidioides brasiliensis

Question 8

Talaromycosis

Answer 8

Talaromyces (Penicillium) marneffei

Question 9

Emergomycosis

Answer 9

Emergomyces (Emmonsia) spp.

Question 10

USA (Midwest, SE, east, SC), Canada (Ontario, Quebec, Manitoba, Saskatchewan), Africa (east, south), India

Answer 10

Blastomycosis

Question 11

Central Valley of California, eastern Washington state, Arizona, Texas, Utah, Mexico, Central & South America

Answer 11

Coccidiodomycosis

Question 12

USA (Ohio, Mississippi River Valleys), Central & South America

Answer 12

Histoplasmosis

Question 13

South America (Brazil, Venezuela, Columbia, Argentina, Paraguay, Ecuador)

Answer 13

Paracoccidiodomycosis

Question 14

China (Guangxi province), Thailand, Hong Kong, India, Taiwan, Laos, Cambodia, Malaysia, Myanmar,
Indonesia, Vietnam

Answer 14

Talaromycosis

Question 15

Asia, Europe, Africa, North America

Answer 15

Emergomycosis

Question 16

_______is a systemic fungal infection caused by_______ spp, primarily______.

It is a thermally dimorphic fungus, existing as a mold in the environment and converting to yeast in human tissues upon inhalation.

The disease predominantly affects the lungs but can disseminate to the (3)

Answer 16

Blastomycosis

Blastomyces species

Blastomyces dermatitidis

skin
bones
CNS

Question 17

Lung infections (79%, 25%-40% disseminated mycosis any organ), preferentially skin, bones, & CNS

Answer 17

Blastomycosis

Question 18

• a.k.a.

North American …
Gilchrist disease
Chicago disease

Answer 18

Blastomycosis

Question 19

BLASTOMYCOSIS

• T.C._____ discovery: budding yeast form in tissues and hyphal organisms in culture from a patient with skin disease in 1894.
• took ______to understand that cutaneous manifestation was associated with pulmonary involvement…

all cases of skin involvement resulted from dissemination from the lungs

Answer 19

Gilchrist’s

50 years

Question 20

Blastomyces species belong to the phylum_____ and the family_____.

Answer 20

Ascomycota

Ajellomycetaceae

Question 21

BLASTOMYCOSIS

•________– primary causative species.
•_______ (2013) – associated with outbreaks; part of the B. dermatitidis species complex.

Answer 21

Blastomyces dermatitidis

Blastomyces gilchristii

Question 22

BLASTOMYCOSIS

•________– infects immunodeficient humans and domestic animals.

•________– found in Africa and the Middle East.

•________ – linked to extrapulmonary infections.

Answer 22

Blastomyces helicus (2017)

Blastomyces percursus (2017)

Blastomyces emzantsi (2020)

Question 23

MOT of BLASTOMYCOSIS

Answer 23

• Inhalation of conidia* (spores) from soil or organic debris.
• Dermal contact with contaminated soil (rare).
• Possible sexual transmission (suggested but not confirmed).

Question 24

Environmental Reservoir

•_______ thrives in wooded areas with damp soil, particularly near lakes, rivers, and waterways.

• Risk Factor: Soil disturbance (excavation, construction) in endemic areas.

Answer 24

Blastomyces

Question 25

Infection Initiation • Inhaled conidia transform into thick-walled, broad-based budding yeasts in the lungs. • yeast form resists phagocytosis by alveolar macrophages, promoting survival and dissemination.

Answer 25

Blastomyces

Question 26

Conidia are inhaled and phagocytosed by alveolar macrophages, where they convert to intracellular yeasts.

Answer 26

Histoplasmosis

Question 27

• Severe disease: Chronic pneumonia (resembles TB), dissemination to liver, spleen, and bone marrow, causing hepatosplenomegaly, pancytopenia, and weight loss. • Risk group: HIV/AIDS patients (disseminated histoplasmosis is an AIDS-defining illness).

Answer 27

Histoplasmosis

Question 28

• Inhaled conidia transform into yeasts with multiple budding (“pilot’s wheel” appearance).

Answer 28

Paracoccidioidomycosis

Question 29

• Severe cases: Chronic pulmonary infection, mucocutaneous ulcers, and lymphadenopathy. • Endemic in South America, primarily affecting male agricultural workers (estrogen inhibits transformation of conidia into yeast, explaining male predominance).

Answer 29

Paracoccidioidomycosis

Question 30

Inhaled conidia develop into intracellular yeasts that multiply within macrophages

Answer 30

Talaromycosis

Question 31

• Disseminated disease: Fever, weight loss, skin lesions, hepatosplenomegaly, and pancytopenia. • Occurs in immunocompromised hosts, especially HIV/AIDS patients in Southeast Asia.

Answer 31

Talaromycosis

Question 32

Newly emerging systemic fungal infection, primarily affecting immunocompromised individuals.

Answer 32

Emergomycosis

Question 33

• Causes disseminated disease with fever, skin lesions, pulmonary and bone marrow involvement. • Endemic in multiple continents (Asia, Europe, Africa, North America)

Answer 33

Emergomycosis

Question 34

Infection Initiation • Inhaled conidia transform into thick-walled, broad-based budding yeasts in the lungs. • yeast form resists phagocytosis by alveolar macrophages, promoting survival and dissemination.

Answer 34

Blastomycosis

Question 35

• Often asymptomatic or self-limited. • Mild cases: Flu-like symptoms (fever, chills, cough, myalgia). • Severe cases: Chronic pneumonia with pulmonary infiltrates, cough, weight loss, and night sweats.

Answer 35

Pulmonary Blastomycosis (79% of cases)

Question 36

Histopathology: • Pyogranulomatous reaction (mixture of neutrophils and granulomas). • Noncaseating granulomas (resembles sarcoidosis).

Answer 36

Pulmonary Blastomycosis (79% of cases)

Question 37

Animal Susceptibility • Dogs are highly susceptible, particularly ***Bluetick Coonhounds.***

Answer 37

Blastomycosis

Question 38

BLASTOMYCOSIS Direct Microscopy (Specimen Examination) • Samples: • Stains: • KOH prep, cytology, or histology (detect yeast). • H&E stain (400× magnification): • Large thick-walled yeasts (8–15 µm). • Broad-based budding (bud enlarges to nearly the same size as parent yeast before detaching).

Answer 38

Sputum, BAL (bronchoalveolar lavage), abscess fluid, or biopsy from granulomatous nodules.

Question 39

BLASTOMYCOSIS Culture Identification Mold Form (25-30°C) on WHAT AGAR???: • Grows in_____(how long??) • Color or colonies???

Answer 39

SDA (Sabouraud Dextrose Agar) 7–14 days Cottony white to brownish mold colonies

Question 40

Culture Identification LPCB mount: • Branching hyphae. • Spherical, ovoid, or piriform-shaped conidia (3–5 µm) on thin stalks. • Larger chlamydospores (7–18 µm) may also be present.

Answer 40

BLASTOMYCOSIS

Question 41

BLASTOMYCOSIS ________(culture extract antigens) – used in skin tests, but lacks specificity. • Complement Fixation (CF) Test: • High titers (_____) in progressive or disseminated disease. • Limited diagnostic value due to cross-reactivity.

Answer 41

Blastomycin ≥1:16

Question 42

BLASTOMYCOSIS ________ of B. dermatitidis – more reliable in: • Immunodiffusion (ID) test. • Enzyme Immunoassay (EIA) – 92% specificity.

Answer 42

Antigen A

Question 43

BLASTOMYCOSIS • Highly sensitive, but ***cross-reacts with Histoplasma*** due to galactomannans in the cell wall.

Answer 43

Urine Antigen Testing (Blastomyces Ag Test):

Question 44

BLASTOMYCOSIS • Virulence factor. • Inhibits TNF (tumor necrosis factor) release, reducing immune response

Answer 44

BAD1 Protein (Blastomyces Adhesin 1):