Ch6 Fungal and Protozoal Flashcards
Candida albicans is dimorphic. Which form is innoculous and which form is pathologic?
Yeast = innoculous…hyphal = invasion of host tissue
What % of people carry candida as normal oral flora?
up to 50%
__________ is typically responsible for an ACUTE(rapid) expression of pseudomembranous candidiasis WHEREAS __________ usually produce a CHRONIC (slow-onset, long-standing) form.
Antibiotic exposure….immunologic problems
What are the 9 clinical types of oral candidiasis?
- Pseudomembranous (thrush) 2.Erythematous: 2a: acute atrophic candidiasis… 2b: Central Papillary atrophy/median rhomboid glossitis 2c: Chronic multifocal 2d: Angular chelitis 2e: Denture stomatitis (chronic atrophic candidiasis, denture sore mouth) 3. Hyperplastic (candidal leukoplakia) 4. Mucocutaneous 5. Endocrine-candidiasis syndromes
Which form of candidiasis is associated with a “bald” appearance of the tongue? What is the alternate name?
erythematous candidiasis (acute atrophic candidiasis)
What is the term for an erythematous candidiasis that presents with central papillary atrophy AND mucosal candidal infection at other sites?
Chronic multifocal candidiasis
What is an alternate name for angular chelitis?
Perleche (PER - Le - CHE)
What are the % break downs for the culprit organisms in angular chelitis?
20% candida alone, 60% candida + staph aureus, 20% staph aureus alone
What is the term for perioral angular chelitis?
CHEILO-CANDIDIASIS
Where is candidal leukoplakia typically located?
anterior buccal mucosa
Which cytokine is critical to mucosal immunity related to C. Albicans?
IL-17
In some patients with mucocutaneous candidiasis, mutations in WHICH GENE have been found?
AIRE (autoimmune regulator)
Young patients with mucocutaneous candidiasis should be evaluated periodically because any one of a variety of _______ abnormalities (i.e., endocrine-candidiasis syndrome, autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy [APECED] syndrome/autoimmune polyendocrinopathy syndrome, type 1), as well as ________, may develop in addition to the candidiasis
ENDOCRINE…iron deficiency anemia
What 4 endocrine disturbances are associated with mucocutaneous candidiasis?
Hyopthyroidism, hypoparathyroidism, hypoadrenocorticism (addison’s disease), and diabetes mellitus
Besides PAS and GMS stains to find candida, what other technique can be used?
KOH prep
What is the organism responsible for histoplasmosis?
Histoplasma capsulatum
What is the treatment for acute and chronic histoplasmosis?
none for acute, chronic gets treated with IV amphoteracin B
What is the causative agent for Blastomycosis?
Blastomyces dermatitidis
What type of agar is used to grow blastomyces?
Sab-our-aud agar
Which fungal infection most closely mimics SCC when it manifests in the oral cavity?
Histoplasmosis
Which 3 fungal infections are known for producing granulomatous inflammation?
Histoplasmosis, Blastomycosis, Aspergillosis
Actue blastomycosis most closely resembles which disease? What about chronic blastomycosis?
active = pneumonia…chronic = TB
What type of cough is seen with blastomycosis?
productive cough
What type of cough is seen with histoplasmosis?
dry cough
Which fungus is known for a doubly refractile cell wall?
blastomyces dermatitdis
Which fungus is known for having pseudoepitheliomatous hyperplasia overlying the infection?
blastomycosis
Which fungal infection: blasto or histo can be discovered with serologic testing?
Histo = serology…blasto won’t show
What animal is known for transmitting the paracoccidiomycosis fungus?
the 9 banded armadillo
What is the male:female ratio of paracoccidio infection?
Male 15:1 Female
What is the name for the oral lesion associated with paracoccidio?
“mulberry-like ulceration”
What are two buzzwords for paracoccidio histology?
“mickey-mouse ears” OR “mariner’s wheel”
What is the name for the causative agent in paracoccidiomycosis?
paracoccidioides brasiliensis
What is the alternate name for paracoccidioides brasiliensis?
South American blastomycosis
What is the causative agent(s) in valley fever (AKA San Joaquin Valley fever)?
coccidioides immitis, coccidioides posadasii
Where in the world is coccidiodes immitis found?
alkaline, semiarid, desert soil of the SOUTHWESTERN United States and Mexico
Where in the world is coccidiodes posadasii found?
Central & South America
Coccidiodes is dimorphic. What form are they in nature? What form are they when they cause an infection in a host?
mold in nature, YEAST in an infected host
Define mold & yeast
mold: one organism with many filaments called hyphae and many identical nuclei as well. Yeast: one cell organism
Which fungal infection can cause an EM-like cutaneous eruption? OR Erythema nodosum
Coccidiodes
What two stains help identify coccidio?
PAS and GMS (gomori methiamaine silver)
What organism transmitts Cryptococcus?
birds, most commonly pigeons (because they live in other bird shit)
What is the morphology of an infectious crypto?
YEAST
Which fungi infect as YEAST?
HBPCC: Histo, Blasto, Paracoccidio, Coccidio, Crypto
Which fungi infect as HYPHAE (mold)?
CAM: Candida, Aspergillosis, Mucor
What two organisms cause Aspergillosis? Which one is MOST common?
Flavus, fumigatus… fumigatus is most common
What is the organism responsible for crypto infection?
cryptococcus neoformans
What was the most life threatening fungal infection in the 1990’s AIDS population?
Crypto
What is unique about crypto’s natural and infectous morphology?
its a YEAST in both nature and in pathologic form
Which fungus can you stain with mucicarmine? Why?
Crypto becuase it has a mucopolysaccharide capsule
What is the bastard stepchild of cryptococcus neoformans that also can cause infection, mostly found in tropical/subtropical environments but outbreaks have been found in the pacific northwest?
Cryptococcus Gattii
What is the key for crypto’s histology?
round/ovoid surrounded by a “halo” (the mucopolysaccharide capsule)
Looks similar to Blasto witht the double-refractile cell wall
What metal is associated with growth of mucor? What two conditions put patients at risk?
iron…insulin dependent diabetics (iron spikes during DKA), thalassemia (pts given deferoxamine to chelate iron)
What is unique about mucor histology? What effect does this have on bodily tissues?
90deg branching…causes necrosis by invading small vessles
What stain can be used at frozen section to point out mucor?
Cal-co-fluor White
What is the second most common fungal infection (behind candidiasis)?
Aspergillosis
Which fungal infection is associated with nosocomial infection?
Aspergillosis
What is the term for the clinical appearance of an allergy affecting the sinuses? What appears histologically?
allergic fungal sinusitis…eosinophilic inspissated mucin with sheets of lymphocytes and eosinophils
What are the 3 names for a mass of aspergillus fungal hyphae?
fungus ball, mycetoma, aspergilloma
What is an aspergilloma called that has undergone dystrophic calcification?
antrolith
What two immunocompromised patients are at highest risk for disseminated aspergillosis?
leukemia or high dose corticosteroids
Where is disseminated aspergillosis first symptomatic?
lungs (site of innoculation)
What is the histology of an aspergillosis hyphae?
branching at acute angles
What is the buzzword for the histology of a fungus ball (aspergilloma) in the paranasal sinus?
spore-bearing structures called fruiting bodies
What stain can help you find aspergillosis?
GMS (Gomori Methenanine Silver)
What is the infectous organism in toxoplasmosis?
toxoplasma gondii
What are two very susceptible populations to toxo?
immunocompromised and fetuses
What animal is the definitive host of toxo? Where in this animal does it mutiply?
cat…GI…excreted in the feces
When does a Toxo infection yeild the most severe effects on a fetus?
1st trimester
What are the TORCH organisms that can be passed from mother to fetus and cause congenital anomalies?
Toxo….Other (syphilis, VZV, Parvo)….Rubella….CMV….Herpes
What are the key histological findings of toxo?
eosinophilic macrophages in germinal centers, subcapsular, and sinusoidal regions of a lymph node
What organism transmits Leishmaniasis? What organism is the natural reservoir?
sandfly = transmission….dogs = reservior
What are the 7 countries most likely to host leishmania?
India, Afghanistan, Saudi Arabia, Syria, Algeria, Peru, and Brazil
What is the name for the female leishmania? What is the name for the flagellated form?
amastigote (no flagella)…promastigotes
Which Leish causes CUTANEOUS Leish in the NEW world?
Leishmania mexicana
Which Leish causes MUCOCUTANEOUS in the new world?
Leishmania braziliensis
Which Leish causes VISCERAL infection in the OLD WORLD?
Leishmania donovani
Which Leish causes VISCERAL infection in the NEW WORLD?
Leishmania braziliensis
Which is the most common form of Leishmaniasis? What is its characteristic skin lesion?
cutaneous…VOLCANO
What is the buzzword for visceral leishmaniasis??
kala-azar = black fever
What morphology of Leishmania is seen on histology?What three special stains can show Leishmania?
The amastigote….Giemsa, Brown-Hopps Gram Stain, or Leishman stain
Since the 1920’s what type of meds were used for Leishmaniasis?
Antimony (heavy metals)
