Fungi and Protists Flashcards
histoplasmosis – primary locations, cell of infection
Mississippi and Ohio River valleys. found in caves, spread by bird and bat feces
Macrophage filled with Histoplasma (smaller
than RBC)
histoplasmosis – primary disease, lung findings
causes pneumonia, presence of caseating granulomas
blastomycosis – primary locations, primary disease and disease signs, defining feature on pathology
States east of Mississippi River, around the Great Lakes and Central America.
Causes inflammatory lung disease
and can disseminate to skin and bone. Forms
granulomatous nodules.
broad-based budding
coccidiomycosis - primary locations, exacerbating factor for transmission. size of fungi
Southwestern United States, California. Case rate increase aftper earthquakes
(spores in dust thrown into air increasing inhaled
spherules in lung).
Spherule (much larger than RBC) filled with
endospores
coccidiomycosis – primary disease, disseminated disease. other disease manifestations, skin, joints?
Causes pneumonia and meningitis. disseminated disease in skin and bone.
“(San Joaquin) Valley fever”
“Desert bumps” = erythema nodosum
“Desert rheumatism” = arthralgias
paracoccidiomycosis - primary locations, key feature on pathology, size of yeast
primarily found in Latin America, captains wheel found in budding yeast, much larger than a red blood cell
common features of systemic mycosis: disease, form at temperature (plus the exception), treatment of choice
all can cause pneumonia especially in immunocompromised individuals
Most are molds at 20°C, beome yeast at 37°C, coccidiomycosis is the exception as it is a spherule at body temperature.
Treatment: fluconazole or itraconazole for local infection;
amphotericin B for systemic infection.
relationship between tuberculosis and systemic mycosis, difference?
both can present as Caseating granulomatous disease, except systemic mycosis does not have person-to-person transfer.
tinea - causative agents of infection x 3, key feature on pathology
Dermatophytes -
include Microsporum, Trichophyton, and Epidermophyton.
Branching septate hyphae visible on
KOH preparation with blue fungal stain A
tinea capitis - location of disease, associated symptoms x3
Occurs on head, scalp. Associated with lymphadenopathy, alopecia, scaling
tinea corporis – location of disease, findings on the skin, infection source
Characterized by erythematous scaling rings (“ringworm”) and central
clearing.
Can be acquired from contact with an infected cat or dog.
tinea cruris – location of disease, difference between tinea corporis
Occurs in inguinal area
Often does not show the central clearing seen in tinea corporis.
tinea Pedis – location of disease, disease types X3
Interdigital ; most common
Moccasin distribution.
Vesicular type
tinea unguium - location of infection
Onychomycosis; occurs on nails
tinea vesicolor - causative agent of disease, primary cell target, time and year of infection.
Caused by Malassezia spp. (Pityrosporum spp.), a yeast-like fungus (not a dermatophyte despite
being called tinea).
Degradation of lipids produces acids that damage melanocytes. hypopigmented and/or pink patches.
Can occur any time of year but common in summer (hot, humid weather)
tinea vesicolor - appearance on pathology, treatment
“Spaghetti and meatballs” appearance on microscopy
Treatment: topical and/or oral antifungal medications, selenium sulfide.
Candida albicans – primary signs of infection, primary demographic of infection,
mouth, leading to oral thrush and esophageal thrush, the vagina, leading to vulvovaginitis, the bloodstream, which can lead to endocarditis,
if disseminated can go anywhere
focuses on the immunocompromised, (chemo, HIV-AIDS, steroids), and IV drug users.
Candida albicans – treatment, vaginal versus oral versus disseminated
topical azole for vaginal;
nystatin,fluconazole, or caspofungin for oral/esophageal
fluconazole, caspofungin, or amphotericin B for systemic.
Aspergillus fumigatus - people likely to be infected
Immunocompromised and those with chronic
granulomatous disease.
Allergic bronchopulmonary aspergillosis - disease associations X2, may cause…
associated with asthma and cystic fibrosis; may cause bronchiectasis and eosinophilia.
TB and aspergillosis - relationship
Aspergillomas in lung cavities, especially after
TB infection.
aspergillosis and liver disease. What is the mediating factor.
Some species of Aspergillus produce aflatoxins,
which are associated with hepatocellular
carcinoma.
Aspergillus – appearance on pathology
Septate hyphae that branch
at 45° angle (left). Conidiophore with radiating chains of
spores (right)
Think “A” for Acute Angles in Aspergillus. Not
dimorphic.
Cryptococcus neoformans – disease X2. Signs on pathology, fungal culture
Cryptococcal meningitis and cryptococcosis (which can lead to pneumonia)
Heavily encapsulated yeast. Not dimorphic, 5-10 μm yeasts with wide capsular halos and unequal budding in India ink stain. Stains with India ink and mucicarmine
Culture on Sabouraud agar.
Cryptococcus neoformans – disease vector x2 and transmission
Found in soil, pigeon droppings. Acquired
through inhalation with hematogenous
dissemination to meninges.
Mucor and Rhizopus fungi. - Population of infection, pathophysiology
Disease mostly in ketoacidotic diabetic and/or neutropenic patients (e.g., leukemia).
Fungi proliferate in blood vessel walls, penetrate cribriform plate, and enter brain.
Mucor and Rhizopus fungi. - disease in face and brain. physical signs of disease, skin face and nerves
Rhinocerebral, frontal lobe abscess; cavernous sinus thrombosis.
Headache, facial pain, black necrotic eschar on face; may have
cranial nerve involvement.
Mucor and Rhizopus fungi. - signs of pathology, treatment.
Irregular, broad, nonseptate hyphae branching at wide
angles
surgical debridement, amphotericin B.
