- Shuffle
Toggle OnToggle Off
- Alphabetize
Toggle OnToggle Off
- Front First
Toggle OnToggle Off
- Both Sides
Toggle OnToggle Off
Front
How to study your flashcards.
Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key
Up/Down arrow keys: Flip the card between the front and back.down keyup key
H key: Show hint (3rd side).h key
PLAY BUTTON
PLAY BUTTON
61 Cards in this Set
- Front
- Back
|
An ascomycete that is dymorphic (mold in soil and yeast in infected humans)
|
Histoplasma Capsulatum
|
|
Fungus that can be stained w/ H&E and is grown with fungal-specific methenamine-silver, PAS stains
|
Histoplasma Capsulatum
|
|
In the lab is grown in rich medium (>1 wk). Its a mold at 25C w/ tuberculate macrocondida and a yeast at 37
|
Histoplasma Capsulatum
|
|
Is found in avian/bat feces.. found worldwide but prevalent in midwestern US esp Mississippi & Ohio valley. Most cases are rural some outbreaks in cities
|
Histoplasma Capsulatum
|
|
An asymptomatic infection up to 90% in endemic area.. symptoms within 2 weeks of mild flu-like to acute fulminating nodular miliary infection to chronic cavitary process resembling Tb
|
Histoplasmosis (Histoplasma Capsulatum)
|
|
Can become disseminated which is most common in very young, elderly, corticoster pts, lymphoma-like dz, AIDs pts.. results in febrile illness w/ enlargement of reticuloendothel. organs (may involve other organs/mucous membranes)
|
Histoplasma Capsulatum
|
|
Can result in pulmonary, disseminated calcifications (common)
|
Histoplasma Capsulatum
|
|
How to diagnostic test for Histoplasma Capsulatum
|
Determine likelihood of exposure
Skin test w/ histoplasmin Ag (+ 2-5 weeks post-infection but persists indefinitely --> useful only in nonendemic areas or when early neg test converts to pos) Direct exam: Sputum or biopsy from reticuloendo tissue --> yeasts within macros Culture H&E stain (Fungal specific methamine silver/PAS) |
|
How to treat Histoplasma Capsulatum
|
Only for severe, pulmonary, chronic cavitary acute/chronic disseminated dz (amphotericin B-IV or itraconazole IV/PO
|
|
Immune response to Histoplasma Capsulatum
|
Phagocytosis --> yeast forms killed by PMNs grow within macros
|
|
A dimorphic fungi (Mold at 25C after 3-4 days.. not readily cultured.. is a biohazard in lab)
|
Cocciodes Immitis
|
|
Spheres w/ Endospheres --> rupture releasing yeast like endospores
|
Cocciodes Immitis
|
|
Grows in warm, alkaline, dry soils. Grows in the SW US. Ppl new to a region are most susceptible
|
Cocciodes Immitis
|
|
In the rainy season, increases surface growth. In the dry season have disintegration of hyphae --> airborne arthroconidia (abundant in dustclouds)
|
Cocciodes Immitis
|
|
Causes Valley Fever
- Positive skin test --> earlier mild, subclinical dz (up to 90% of natives of endemic region) may be asymptomatic |
Cocciodes Immitis
|
|
May have a flu-like illness 1-4 wks post infection w/ a fever, cough, bone/joint pain, weight loss, chest pain, soar throat, hoarseness
|
Cocciodes Immitis
|
|
May cause severe pulm disseminated dz (erythema nodosum skin lesions, subQ granulomatous lesions, may ulcerate)... meningeal involvement --> headache, lethargy, other inflammatory CNS findings
-- May be reactivated in AIDS pts |
Cocciodes Immitis
|
|
How to test for cocciodes immits?
|
Should be considered w/ flu-like illness following visit to endemic area..
-- Perform skin test --> + 1-2 wks post-illness (can persist indefinitely) --> can be negative w/ acute dissem dz -- Serologic for precipitin Ab (+ in 2-3 wks), complement fixing Ab (increased titer after 2-3 mos) Direct exam: Sputum, biopsy --> spherules w/ internal endospores Culture |
|
How to treat cocciodes immits?
|
-- Only indicated in severe pul w/ rising complent fixing Ab, disseminated dz and esp meningitis
-- Meningitis infection: Prolong, high amphotericin B intracisternally -- Chronic Pulm Dz: Azoles -- Surgical removal of lesions |
|
A dimorphic mold @ 25C.. typical broad based budding yeast at 37C in > 1 wk
|
Blastomyces dermatitidis
|
|
Most cases occur in 20-50 yo males in rural areas of SE and north/central US
High mortality rate w/o treatment |
Blastomyces dermatitids
|
|
# a flu-like illness with fever, chills, myalgia, headache, and a nonproductive cough which resolves within days.
# an acute illness resembling bacterial pneumonia, with symptoms of high fever, chills, a productive cough, and pleuritic chest pain. # a chronic illness that mimics tuberculosis or lung cancer, with symptoms of low-grade fever, a productive cough, night sweats, and weight loss. |
Blastomycosis (Blastomyces dermatitidis)
|
|
Can cause resp infection (lobar pneumo), disseminates to skin subQ tissue, bone, etc
|
Blastomyces Dermatidis
|
|
Early symptoms include anorexia and malaise
|
Blastomyces Dermatidis
|
|
Skin lesions are papular --> ulcerate --> necrotic w/ central healing
|
Blastomyces Dermatidis
|
|
How to test for Blastomyces Dermatidis
|
Direct exam of sputum, biopsy from margins of skin ulcers --> typical broad-based budding yeast
Culture at 25 or 27C for over a week |
|
How to treat for Blastomyces Dermaitids
|
In disseminated dz, 90% untreated die.. amphotericin B cures 80%
For chronic dz: Azoles |
|
Is dimorphic.. mold @ 25C and yeast (w/ characteristic parent cell w/ peripheral buds at 37C)
|
Paracoccidiodes Brasiliensis
|
|
Found in warm, wet areas of South America, Mexico
|
Paracoccidiodes Brasiliensis
|
|
A respiratory infection which disseminates --> chronic granulomatous dz w/ pulm or LN involvement, lesions of mucocutaneous areas, various organs, diffuse lung fibrosis
|
Paracocciodes Brasiliensis
|
|
How to test for Paracocciodes Brasiliensis
|
Skin Test
Culture |
|
How to treat for Paracocciodes Brasiliensis
|
Disseminated Dz: Amphotericin B
Pulm Dz: Azoles |
|
An ascomycete (sexual spores within ascus). Forms filamentous fungus (mold) --> wide septate hyphae, dichotomous branching @ 45 angle
Aerial mycelia --> conidiophore --> asexual conidia |
Aspergillus
|
|
Saprophytes that are ubiquitous in nature (airborne conidia are variable)
|
Aspergillus
|
|
Secrete proteinases: Increase invasion, also inhibit mucociliary system and cause phagocyt
|
Aspergillus
|
|
Most common type of Apergillus pathogen?
|
A. Fumigatus (also flavus, niger, etc)
|
|
Primary host defense against aspergillus?
|
PMN
|
|
May cause an allergic rxn, pulmonary or invasive dz, or allrgic bronchopulm dz
|
Aspergillus
|
|
In atopic pts causes acute asthmatic rxn (w or w/o rhinitis/wheezing). Mediated by reaginic (skin-sensitizing non-precipitating specific IgE) Ab
Major allergen is serine protease |
Aspergillus
|
|
How to test for Aspergillus (following asthma)
|
Type 1 skin test rxn (immed wheal & flare)
Precipitins are uncommon |
|
What predisposes someone to allergic bronchopulm aspergillosis?
|
Atopy, high conidia counts, CF
|
|
Prolonged exposure can cause severe asthmatic dz --> bronchiectasis/potentially fatal
|
Allergic bronchopulm Aspergillosis
|
|
Goes from Type 1 to Type 3 rxn.. circulating Ab combines w/ pulm Ag --> PMN, lymphocyte infiltration
|
Aspergillus
|
|
How to test for allergic bronchopulm aspergillosis
|
CXR: fleeting pulm infiltrates
CT: Central bronchiectasis Skin test: Immed. wheal & flare --> later arthus type rxn w/ edema Blood eosinophilia Precipitans are common |
|
How to treat Allergic rxn and Allergic bronchopulm aspergillosis?
|
Corticosteroids Prednisolone w or w/o Itraconazole
|
|
What increases the chance of having pulmonary aspergilloma (fungus ball)
|
TB, sarcoidosis, emphysema, cavitary carcinoma
|
|
Causes hyphal mass to grow in devitalized area of the lung.. asymptomatic to cough w/ hemoptysis
|
Aspergilloma
|
|
How to test for Aspergilloma
|
CXR, skin tests are generally negative, Precipitins are common
|
|
How to treat for Aspergilloma?
|
Amphotericin B + flucytosine --> often infective (if necessary surgical removal)
|
|
Active fungal growth following immunosuppression, high mortality
|
Pulmonary/Invasive Aspergillosis (Aspergillus)
|
|
How to test for Pulmonary/Invasive aspergillus?
|
Histopath --> septate hyphae w/ acute branching
|
|
How to treat for Pulmonary/Invasive aspergillus
|
Control underlying condition, relieve immunosuppression
-- Surgical excision, maximize drainage -- Requires aggressive amphotericin B or azole (consider low dose prophylaxis) -- If refractory to amph B --> capsofungin (echinocandin), voriconazole |
|
Broad septate hyphae branching at 90 Angle
|
Zygomycetes
|
|
Abundant aerial mycelia w/ sporangia sacs containing asexual sporangiospores (conidia)
-- Characteristic sexual spore-containing structure -- Ubiquitous thermotolerant saprophyte |
Zygomycetes
|
|
Most common Zygomycetes species?
|
Rhizopus, Absidia, Rhizomucor, Mucor
|
|
Causes ketoacidosis (from DM, drugs, uremia) --> Fe transferred from transferrin @ low pH --> increased growth
|
Zygomycetes
|
|
What increases chance of Zygomycetes infection?
|
-- Metal chelation therapy w/ deferoxamine (acts as Fe siderophore which zygomycetes can take up)
-- Burn pts, leukemias, immunodeficiencies, Tb |
|
Often infects face, oropharygneal cavity --> thrombosis/necrosis
|
Zygomycoses (Zygomycetes)
|
|
Rhinocerebral -> predilection for CNS, gain entry through nasal mucosa, sinuses: ocular palate lesions are common
Pulmonary: bronchitis, lobular pneumo GI Manifestations |
Zygomycetes
|
|
How to test for Zygomycetes
|
Direct exam: Pus, sputum, nasal discharge, CSF, blood etc--> environmental contam common
Culture: Contam common (specimins should be from normally sterile sites) Histopath (most useful): nonseptate 90Angle branching hyphae |
|
How to treat for Zygomycetes
|
(Same as Invasive Aspergillosis)
-- Control underlying condiion (if possible relieve immunosupp) -- Surgical excision (maximize drainage) -- Aggressive ampho B/ azole (consider low dose prophylax) -- If refractory to Amph B --> Caspogungin (echinocandin), voriconazole) |
