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 Paracoccidioides brasiliensis Penicillium marneffei

Histoplasma capsulatum Coccidioides immitis (posadasii) Penicillium marneffei as major opportunistic pathogens in individuals with AIDS!

Blastomycosis

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 fungus Histoplasma capsulatum 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

tuberculate macroconidia

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