Microbio mycology

Question 1

what are the systemic mycoses (cause PNA and can disseminate, treat with fluconoazole or itraconazole for local infection and amph B for systemic infection)

Answer 1

note that all are caused by dimorphic fungi (cold= mold; heat=yeast), except cocciodioidomycosis; histo ,blast, coccidioido, paracoccidioido

Question 2

histoplasmosis

Answer 2

mississippi and ohio river valley; causes PNA; macrophage filled with histo; bird or bat droppings

Question 3

blastomycosis

Answer 3

east of mississippi river and central america; inflamm lung disease can can dissem to skin and bone; granulomatous nodules; broad-based budding

Question 4

coccidiodomycosis

Answer 4

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

Question 5

paracoccidioidomycosis

Answer 5

Latin america; budding yeast with captain’s wheel formation

Question 6

what are the cutaneous mycoses?

Answer 6

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

Question 7

tinea capitis

Answer 7

on head, scalp; assoc with lymphadenopathy, alopecia, scaling

Question 8

tinea corporis

Answer 8

on body; erythematous scaling rings (“ring worm”) and central clearing; can be acquired from contact with infected dog or cat

Question 9

tinea pedis

Answer 9

interdigital (most common), mocassin distribution, or vesicular type

Question 10

tinea ungulum

Answer 10

onychomycosis; occures on nails

Question 11

tinea versicolor

Answer 11

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

Question 12

what are the opportunistic fungal infections?

Answer 12

candida albicans, aspergillus, crytpo neofromans, mucor and rhizopus, pneumocystis jirovecci

Question 13

candida albicans

Answer 13

oral and esoph thrush in immunocompromised, vulvovaginitis, diaper rash, endocarditis in IVDU, chronic mucocutaneous candidiasis

Question 14

treatment of vaginal, oral/esoph, and systemic candida albicans

Answer 14

topical azole for vaginal; nystatin, fluconazole, or caspofungin for oral/esoph; fluconazole, caspo, or amphotericin B for systemic

Question 15

aspergillus fumigatus

Answer 15

“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

Question 16

cryptococcus neoformans

Answer 16

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

Question 17

mucor and rhizopus

Answer 17

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

Question 18

pneumocystistis jirovecii

Answer 18

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

Question 19

sporothrix schenckii

Answer 19

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