MYCOLOGY SYSTEMIC MYCOSES Dimorphic Primary systemic pathogens Normal

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 southern China • Only species of Penicillium, pathogenic dimorphic fungus • Soluble red pigment diffusing in agar • Laboratory acquired infection • From bamboo rats and from soil