FUNGI Flashcards
Produces the carcinogen aflatoxin and is a common contaminant of moldy nuts and grains
Aspergillus favus
-aflatoxins contribute to the development of HEPATOCELLULAR CARCINOMA and act SYNERGISTICALLY WITH HBV to promote carcinogenesis
Proliferation of this organism within the lung causes a “fungus ball” that must be removed surgically
Aspergillus fumigatus
-microscopically, the organism grows as SEPTATE HYPHAE, branching at 45 DEGREE ANGLES
Although an opportunistic mycosis, it can cause hypersensitivity pneumonitis such as Farmer’s lung
Aspergillus fumigatus
-resulting from inhalation of MOLDY HAY
Systemic mycosis that begins as lower respiratory tract infection and may disseminate to cause warty-like skin lesions
Blastomyces dermatitidis
-results in GRANULOMATOUS LUNG LESIONS SIMILAR TO TUBERCULOSIS; may also result in skeletal and genitourinary manifestations
Systemic mycosis endemic to the southeastern US
Blastomyces dermatitidis
-fungi appears in infected tissue as yeast with BROAD-BASED BUDDING
Causes a cottage cheese-like vaginal discharge
Candida albicans
-predisposing factors include IMMUNOSUPPRESSION, DIABETES, obesity, and the use of BROAD SPECTRUM ABX
Causes white curd-like patches on the mucocutaneous membranes of the mouth and extend downward to cause esophagitis in immunocompromised patients
Candida albicans
-in addition to causing THRUSH, C. albicans is a common cause of TINEA UNGUIUM [fungal infection of nails] and DIAPER RASH
Most common mycotic pathogen
Candida albicans
-although a YEAST, it can form PSEUDOHYPHAE in infected tissue and form characteristic GERM TUBES AT 37 DEGREES CELSIUS under lab conditions
Systemic mycosis endemic to the San Joaquin Valley in southern California
Coccidioides immitis
-causes “VALLEY FEVER” characterized by arthralgias, cough, and fever
Found within infected tissue as spherules that rupture to release endospores
Coccidioides immitis
-dimorphic fungi with contraction of infection by INHALATION OF ARTHROSPORES in the sand and soil
The only mycotic pathogen with a capsule
Cryptococcus neoformans
-visualized with an INDIA INK TEST; capsule EXCLUDES ink, providing CONTRAST
Causes meningitis in patients with underlying immunodeficiency, especially AIDS
Cryptococcus neoformans
-associated with PIGEON DROPPINGS, this fungus grows within the Virchow-Robin vascular spaces of the brain, resulting in “SOAP BUBBLE LESIONS”
Causes cutaneous infections such as tinea corporis, tinea cruris (jock itch), and tinea pedis (athlete’s foot)
Dermatophytes
-typically caused by dermatophytes of the genera Trichophyton spp. and result in scaly hypo- or hyperpigmented ANNULAR PRURITIC LESIONS
Associated with the inhalation of spores from bird or bat droppings in the Ohio and Mississippi river valley
Histoplasma capsulatum
-histologically characterized by MACROPHAGES STUFFED WITH NUMEROUS YEAST CELLS
Most common pulmonary mycotic infection with symptoms ranging from asymptomatic to tuberculosis-like symptoms
Histoplasma capsulatum
-in immunocompetent individuals, infection often resolves, with CALCIFICATION OF HILAR LYMPH NODES
Causes tinea versicolor, which manifests as patches of hyper- and hypopigmentation on the trunk
Malassezia furfur
-found in skin scales and has a characteristic SPAGHETTI AND MEATBALLS APPEARANCE [yeast clusters and short, curved septate hyphae]
Most common cause of tinea capitis, ringworm of the scalp
Microsporum canis
-common in PREPUBESCENT CHILDREN WITH PETS; the natural inhibitor of Microsporum spp. growth, UNDECYLENIC ACID, is produced in the sebum of postpubertal individuals
Results in rhinocerebral disease, primarily in patients with diabetic ketoacidosis or leukemia
Mucor and Rhizopus species
-distinct from other human fungal pathogens in that these species cause disease in their SEXUAL LIFE CYCLE and display NONSEPTATE HYPHAE BRANCHING AT 90 DEGREE ANGLES OR WIDER
This organism grows as multiple budding yeasts that appear as “captain’s wheel” and causes disease almost exclusively in men
Paracoccidioides braziliense
-this GRANULOMATOUS LUNG DISEASE occurs primarily in CENTRAL AND SOUTH AMERICA, with >90% of cases seen in males
Causes an alveolar pneumonia, typically in AIDS patients
Pneumocystis carinii
-previously thought to be a protozoa, this fungus causes a FOAMY, AMORPHOUS ALVEOLAR EXUDATE AND is seen as CUP or BOAT-SHAPED CYSTS upon staining with SILVER METHENAMINE
Causes the most common subcutaneous mycosis, Rose handler’s disease
Sporothrix schenckii
-transmitted by the prick of a contaminated THORN; treated with dilute solution of POTASSIUM IODIDE IN MILK
Produces a toxin that results in liver damage upon ingestion of wild mushrooms
Amanita species
-ingestion may result in life-threatening FULMINANT HEPATITIS, requiring liver transplant
