Test 3 Wk11: 11 Respiratory Fungal Infections - Shah Flashcards
North American Blastomycosis Causative Agent:
B.dermatitidis
B.dermatitidis is — in nature
dimorphic
B.dermatitidis location
Ohio & Mississippi River
valleys, the Great Lakes,
and in the southeast
Clinical Presentation
Blastomycosis : B.Dermatitidis
Flu like symptoms
B.Dermatitidis Acute pulmonary
Acute pulmonary: lobar
segmental consolidation,
Mimics bacterial pneumonia .
B.Dermatitidis Chronic pulmonary
Chronic pulmonary lobar infiltrates
Mimics tuberculosis or lung
cancer
— Can disseminate to skin & bone in immunocompromised patients
B.Dermatitidis
B.Dermatitidis is acquired by
acquired by inhaling spores:
dissemination Suppurative
granulomatous;
— often misdiagnosed are carcinoma
B.Dermatitidis
Diagnosis & Treatment :
B.Dermatitidis
KOH preparation:
Sputum, BAL, lung tissue, skin biopsy,
B.Dermatitidis Yeast form is
Yeast form is large (8-12 um), round, thick walled and
hyaline
Histoplasmosis:
H. capsulatum
H. capsulatum location
Ohio and Mississippi
river valleys in the USA.
H. capsulatum elicits — similar to —
Elicits granulomas; TB
H. capsulatum animals
birds and bats
H. capsulatum comes from soil that is
high N content
H. capsulatum forms — in the body
histocytes
H. capsulatum is
dimorphic
Histoplasmosis
clinical presentation
variable
asx in healthy; can dissiminate in immunosuppressed
Histoplasmosis
clinical presentation rare cases
Acute Respiratory Distress Syndrome
Acute respiratory distress syndrome in Histoplasmosis
10% inflammatory sequelae, such as persistent
lymphadenopathy with bronchial obstruction,
arthritis, arthralgias , or pericarditis,
Mediastinal fibrosis: ARDS Histoplasmosis
Persistent host response to
the organism may result in massive fibrosis and
constriction of mediastinal structures, including
the heart and great vessels.
H. capsulatum
Diagnosis & Treatment
Direct microscopy
Culture of blood, bone, marrow or other material
enzyme immunoassay
The yeast phase of H. capsulatum organism can be detected in:
Sputum, BAL, fluid,
peripheral blood films, bone
marrow, and tissue stained
H. capsulatum found can be seen in tissue stained with
with Giemsa, GMS, or PAS
stains
H. capsulatum PAS stain
appears
appears as a small yeast about 5-6 microns in diameter
Coccidioidomycosis
C. Immitis & C.posadasii
Coccidioidomycosis located in
southwest
Coccidioidomycosis also known as
San Joaquin Valley Fever
Coccidioidomycosis environment
Arid, alkaline soils, hot
summers.
Coccidioidomycosis outbreaks
dust storm and earthquakes
which Coccidioidomycosis accounts for the majority of infections outside of California
C. posadasii
Coccidioidomycosis are
dimorphic
Coccidioidomycosis forms — at 37C
Spherules
Coccidioidomycosis spherules can be mistaken as
toxoplasma gondii tissue cysts
Coccidioidomycosis forms — in the environment
Arthroconidia
Coccidioidomycosis Clinical presentation
Variable; usually self limited; can be life threatening;
Coccidioidomycosis is known as the great imitator and mimics
syphilis, typhoid,
Coccidioidomycosis sx
fever, cough, chills, pleurisy, arthralgia
Coccidioidomycosis extrapulmonary sites of infection
skin soft tissue bones joints meninges
Coccidioidomycosis risk factors
Filipino, African American, Native American, Hispanic
Male
Women in 3rd trimester
Depressed cell mediated immunity
Coccidioidomycosis pathology
Necrotizing granulomatous inflammation
pneumonitis
huge (20 60 µm) round thick walled spherule under microscope full of smaller endospores
Diagnosis: Coccidioides immitis
sputum pus from skin lesions gastric washings CSF biopsy
Coccidioides immitus stain
Calcofluor white stain
Paracoccidiodes brasiliensis is
dimorphic
Paracoccidiodes brasiliensis forms — at 37C
“pilots wheel” multipolar arrangement
Paracoccidioidomycosis
Clinical Presentation
Granulomatous disease of
mucous membranes, skin, and
pulmonary system.
25% patients exhibit, pulmonary manifestations of Paracoccidioidomycosis can
which can disseminate to
extrapulmonary sites w/out tx
Paracoccidioidomycosis Diagnosis
Examination of sputum
BAL
scrapings or biopsy
pus draining from lymph nodes
CSF
tissue
Paracoccidioidomycosis Histopathology
multiple buds forming a “Captain’s wheel.“ “Pilot’s wheel”
C. Neoformans
Capsule
Aspergillilus hyphae
Mold with septate
Pneumocystis jirovecii
Cup shaped fungus
Histoplasma capsulatum , a dimorphic fungus, is found in
soil heavily contaminated with bird droppings. Which of
the following statements best describes the presence of
the organism in tissue biopsies?
Oval Budding yeast inside macrophages
Histoplasma is prevalence in which part of the USA?
Ohio and Mississippi
river valleys in the USA.
Coccidioides immitis
A dimorphic fungus, which produces “Spherule” in its tissue phase.
Blastomyces dermatitidis
A dimorphic fungus most commonly found in soils of Northeastern
USA which is also an important veterinary problem
Cryptococcus neoformans
A yeast acquired by inhalation that causes respiratory infection
primarily in immunocompromised patients
