Microbio mycology Flashcards
what are the systemic mycoses (cause PNA and can disseminate, treat with fluconoazole or itraconazole for local infection and amph B for systemic infection)
note that all are caused by dimorphic fungi (cold= mold; heat=yeast), except cocciodioidomycosis; histo ,blast, coccidioido, paracoccidioido
histoplasmosis
mississippi and ohio river valley; causes PNA; macrophage filled with histo; bird or bat droppings
blastomycosis
east of mississippi river and central america; inflamm lung disease can can dissem to skin and bone; granulomatous nodules; broad-based budding
coccidiodomycosis
southwestern US, CA; pneumonia and meningitis, can dissem to bone na dskin; increased rate after earthquake as spores are thrown into the air; San Joaquin Valley fever, erythema nodosum, arthralgias
paracoccidioidomycosis
Latin america; budding yeast with captain’s wheel formation
what are the cutaneous mycoses?
tinea capitis, tinea corporis, tinea cruris, tinea pedis, tinea ungulum, tinea versicolor; for all of these, branching septate hyphae visitble on KOH prep with blue fungal stain
tinea capitis
on head, scalp; assoc with lymphadenopathy, alopecia, scaling
tinea corporis
on body; erythematous scaling rings (“ring worm”) and central clearing; can be acquired from contact with infected dog or cat
tinea pedis
interdigital (most common), mocassin distribution, or vesicular type
tinea ungulum
onychomycosis; occures on nails
tinea versicolor
caused by malassezia species, a yeast-like fungus (not a dermatophyte, despite being caused tinea); acids damage melanocytes and cause hypopigmented or pink patches; spaghetti and meatballs appearance on microscopy; treat with topical and/or oral antifungal meds, selenium sulfide
what are the opportunistic fungal infections?
candida albicans, aspergillus, crytpo neofromans, mucor and rhizopus, pneumocystis jirovecci
candida albicans
oral and esoph thrush in immunocompromised, vulvovaginitis, diaper rash, endocarditis in IVDU, chronic mucocutaneous candidiasis
treatment of vaginal, oral/esoph, and systemic candida albicans
topical azole for vaginal; nystatin, fluconazole, or caspofungin for oral/esoph; fluconazole, caspo, or amphotericin B for systemic
aspergillus fumigatus
“A” Acute Angles in Aspergillus; invasive aspergillosis, esp in immunocomp and those with chronic granulomatous disease; allergic bronchopulmonary aspergillosis (assoc with asthma and CF); aspergillomas in lung cavities, esp after TB infection; some species assoc with HCC
cryptococcus neoformans
crytpo meningitis; heavily encapsulated yeast; found in soil, pigeon droppings; stains with India in and mucicarmine; cx on Sabouraud agar; “Soap bubble” lesions in brain
mucor and rhizopus
disease mostly in ketoacidotic diabetic and/or neutropenic patients (e.g. leukemia); fungi proliferate in the blood vessel walls, penetrate cribiform plate, and enter the brain; assoc with frontal lobe abscess, cavernous sinus thrombosis; HA, facial pain, black necrotic eschar on face, may have CN involvement; treat with surgical debridement and amphotericin B
pneumocystistis jirovecii
causes PCP pneumonia, a diffuse interstitial PNA; diffuse, bilateral ground-glass opacities; dx by lung bx or lavage; disc-shaped yeast form on methenamine silver sain of lung tissue; treatment/prophylazis with TMP-SMX, pentamidine, dapsone, atovaquone
sporothrix schenckii
sporotrichosis; dimorphic, cigar-shaped budding yeast that lives on vegetation; spores can be traumatically introduced into the skin (“rose gardener’s disease), you get a local pustule or ulcer with nodules along draining lymphatics (ascending lymphagitis); treat wth itraconazole or potassium iodide
