RTI VIII Flashcards
list the primary fungal pathogens
- primary (healthy & immunocompetent)
- Histoplasma capsulatum
- Blastomyces dermatidis
- Coccidiodes immitis
- Paracoccidiodes brasiliensis
list the opportunistic fungal pathogens
- opportunistic (immunocompromised individuals)
- Cryptococcus neoformans
- Aspergillus sp.
- Pneumocystis jiroveci
all primary fungal RTIs are acquired via ____ and all are _____
all primary fungal RTIs are acquired via inhalation and all are dimorphic
____ & ____ are endemic in the area of the Mississippi River Valley and the Ohio River Valley
H. capsulatum & B. dermatitidis are endemic in the area of the Mississippi River Valley and the Ohio River Valley
____ is endemic in the area of Southwestern US and Northwestern Mexico
C. immitis is endemic in the area of Southwestern US and Northwestern Mexico
list the clinical features of fungal RTIs
fungi that cause RTIs are able to convert to form ____
fungi that cause RTIs are able to convert to form capable of replication at 37 C
- mycelial → yeast form
- may enhance survival of the fungi since yeasts aren’t killed as easily by phagocytes
- colonize resp. mucosa
describe how H. capsulatum can grow inside macrophages
- H. capsulatum
- can increase phagolysosomal pH
- interferes with enzyme activity and antigen processing
the composition of the ___ may be important in the pathogenesis of fungi
explain this
the composition of the cell wall may be important in the pathogenesis of fungi
- certain components linked with virulence
- e.g. virulence in P. brasiliensis is linked to presence of α-(1,3)-glucan in cell wall
describe obtaining samples and techniques used for diagnosing fungal RTIs
delayed hypersensitivity skin tests are useful for diagnosis of _____
delayed hypersensitivity skin tests are useful for diagnosis of Coccidiodomycosis
- mycelial phase antigen: coccidioidin
- spherule phase antigen: spherulin
describe the exoantigen test
- exoantigen test:
- basis = immunodiffusion
- look for presence of specific cell free antigens produced by mycelial phase of the fungi
- basis = immunodiffusion
the natural habitat of Histoplasma capsulatum is _____, such as that enriched with ____
the natural habitat of Histoplasma capsulatum is soil with high nitrogen content, such as that enriched with bird or bat droppings
acquiring Histoplasmosis is dependent on… (2 things)
name the 2 clinically significant varieties of Histoplasma
-
H. capsulatum var capsulatum
- pulmonary and disseminated infections
- Eastern US and Latin America
- thinner cell walls, smaller size
-
H. capsulatum var duboisii
- __skin and bone lesions
- tropical Africa
- thick walled; larger yeasts