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MYCOLOGY. SYSTEMIC MYCOSES. Dimorphic Primary systemic pathogens Normal and immunocompromised hosts From inhalation to deeper viscera. Blastomyces dermatitidis Coccidioides immitis Coccidioides posadasii Histoplasma capsulatum var capsulatum Histoplasma capsulatum var duboisii
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SYSTEMIC MYCOSES • Dimorphic • Primary systemic pathogens • Normal and immunocompromised hosts • From inhalation to deeper viscera • Blastomyces dermatitidis • Coccidioides immitis • Coccidioides posadasii • Histoplasma capsulatum var capsulatum • Histoplasma capsulatum var duboisii • Paracoccidioides brasiliensis • Penicillium marneffei
Histoplasma capsulatum • Coccidioides immitis (posadasii) • Penicillium marneffei as major opportunistic pathogens in individuals with AIDS!
chronic granulomatous and suppurative disease • a primary pulmonary stage , frequently followed by dissemination to other body sites, chiefly the skin and bone • yeast form: spherical, hyaline, multinucleated, thick double contoured walls reproduce by buds or blastoconidia • mold form: Round-oval , pear-shaped conidia, located on long or short hyphal branches
inhalation of conidia from fungus in soil or leaf • Not transmitted from patient to patient • Lab-acquired ptimary cutaneous and pulmonary blastomycosis reported
Coccidioidomycosis • inhalation of arthroconidia • asymptomatic infection to death • variety of lesions...............the great imitator • coccidioidal granuloma • San Joaquin Valley fever • Endosporulating spherule in tissue • Barrel-shaped conidia
After inhalation, arthroconidia rounded converting to spherules in the lung • Rupture of spherules walls , endospores release • Progressive pulmonary disease • Skin, soft tissues, bones,joints, meninges • Laboratory diagnosis: • initial screening tests: immunodiffusion (ID) test and latex particle agglutination (LP) test
Histoplasmosis • intracellular mycotic infection of the reticuloendothelial system caused by the inhalation of microconidia from the fungusHistoplasmacapsulatum • Histoplasma capsulatum var capsulatum...pulmonary and disseminated infections • Histoplasma capsulatum var duboisii......skin and bone lesions
in areas contaminated with bird or bat droppings, high nitrogen content • reactivation , dissemination is common in immunsuppressed individuals especially with AIDS • Laboratory diagnosis: • Detection of antigen in serum and urine
Paracoccidioidomycosis • South American blastomycosis • Latin American countries • chronic granulomatous disease that characteristically produces a primary pulmonary infection, often inapparent, and then disseminates to form ulcerative granulomata of the buccal, nasal and occasionally the gastrointestinal mucosa • inhalation or traumatic inoculation • Cultures should be manipulated in safety cabinet
Penicilliosis Marneffei • involves the mononuclear phagocytic system • Primarily in HIV-infected individuals in Thailand and southern China • Only species of Penicillium, pathogenic dimorphic fungus • Soluble red pigment diffusing in agar • Laboratory acquired infection • From bamboo rats and from soil