Mycology 2 Flashcards
causes Sporotrichosis (subcutaneous mycosis)
Sporothrix schenckii
where can you find Sporothrix schenckii fungus?
sphagnum moss, hay, plant materials, soil
Sporothrix schenckii grows as this at ambient temperature; how does it grow at 37C?
branching septate hyphae (with single or clustered microcondia); elongated yeasts
treatment for Sporothrix schenckii infection in cutaneous lesion
itraconazole or fluconazole
treatment for Sporothrix schenckii infection for lymphocutaneous, pulmonary, disseminated disease
amphotericin B
where is primary systemic mycosis initiated?
lung
three fungi that cause primary mycosis infection
Coccidioidomycosis, Histoplasmosis, Blastomycosis
inhalation of this causes San Joaquin Fever/Valley fever
Coccidioides immitis spores (Coccidioidomycosis)
at ambient temperature…Coccidioides immitis (branching, septate, hyphae) forms these; what is formed at 37C?
arthrospores; spherules (containing endospores)
patient will present with these symptoms in disseminated Coccidioidomycosis
sweating, dyspnea, fever, weight loss
how long does it take for disseminated Coccidioidomycosis progress/occur
weeks-2 years
risk factors for disseminated Coccidioidomycosis
advanced age, immunocompromised
disseminated Coccidioidomycosis has predilection for these areas of body
skin, bone, joints, CNS
where is Coccidioidomycosi endemic in USA?
Southern Texas, Arizona, California (desert soil…drought/rain enhance fungus dispersion, bat and rodent droppings enhance growth)
most prevalent mycotic infection in humans and animals
Histoplasmosis
two variations of Histoplasma capsulatum that cause histoplasmosis
capsulataum and duboisii
Histoplasma capsulatum form these at ambient temperature (grow as branching, septate hyphae); how do they grow at 37C?
microcondia and tuberculae macrocondia; small ovoid budding yeast cells
form of Histoplasma capsulatum in soil; what is inhaled by humans?
mycelial; conidia
this causes Blastomycosis…dimorphic fungi
Blastomyces dermatitidis
how does Blastomyces dermatitidis grow at ambient temperature? how does it grow at 37C?
septate hyaline hyphae, unbranched short conidiophores; budding yeast cells
what does Blastomyces dermatitidis most commonly cause?
chronic granulomatous disease
does Sporothrix schenckii have micro or macrocondia at ambient temp?
microcondia
does Histoplasma capsulatum form micro or macrocondia?
microcondia and tuberculate macrocondia
symptoms of Sporotrichosis appear this long after exposure to Sporothrix schenckii
1-12 weeks
characterized by inflamed and pussy subcutaneous nodules that progress along lymphatic channels; what do these lesions eventually become?
lymphocutaneous sporotrichosis; ulcerations
is caused by direct inoculation or haematogenous seeding of bones
osteoarticular sporotrichosis
various infections sporotrichosis can manifest as
lymphocutaneous, pulmonary, osteoarticular, disseminated
where is C. immitis found? what phase is located here?
soil; mycelial arthrospore
when conditions become dry…C. immitis hyphase develop arhtrospores, that then dissemiinate to this (become airborne and viable for long time in soil)
arthrocondia
phase of C. immitis in infected tissue (becomes this after entering human)
spherule endospore (continually open and release hundreds of endospore…which develops into new spherule)
symptomatic respiratory syndrome (mild-flu like presentation) appears this amount of time after C. immitis infection
1-3 weeks (95% recover in a few weeks)
5-8% of patients with primary pulmonary coccidioidomycosis develop this…due to failure of immune defenses; what is most common form?
chronic coccidioidomycosis; cavity or nodule formation
sign of disseminated disease of coccidioidomycosis…hypersenstivity reaction in subcutaneous tissue, appears at anterior surface of lower extremities commonly
erythema nodosum
sign of disseminated disease of coccidioidomycosis…pink-red ring around pale center (Target lesion)
erythema multiforme
signs of disseminated disease of coccidioidomycosis
skin rash, meningitis, migratory arthralgias
presence of arthralgias, fever, and erythema nodosum
Desert Rheumatism
form of C. immitis that is inhaled (deposited in terminal bronchiole)
arthroconidia
in coccidioidomycosis…these react with complement to promote chemotaxis
spherules
in coccidioidomycosis…these are engulfed by MP to initiate acute inflammation phase (if isn’t cleared, will recruit more lymphocytes and granuloma will form)
endospores
diagnosis for coccidioidomycosis
spherules in sputum, exudate, tissues in KOH
mycelial phase antigen that can be used to detect Ab in coccidioidomycosis diagnosis
coccidioidin
elevated levels of this is marker for disseminated, extrapulmonary disease
IgG
treatments for coccidioidomycosis
oral fluconazole, itraconazole, AmB
who are at risk for histo infection?
smokers, immunocompromised and children
what may chronic pulmonary histo resemble?
pulmonary TB (coughing blood, fever, sweating, chest pain, shortness of breath)
may see mouth sores and skin lesions in this form of histo
disseminated
what form of histo is inhaled? where does this develop into yeast?
microconidia; alveolar MP
men with this condition are susceptible for chronic pulmonary histo infection
emphysema
can detect this antigen in blood, urine, or CSF for histo diagnosis
capsular antigen
treatment for histoplasmosis
itraconazole and AmB
this causes acute pulmonary mimic of bacterial TB (fever, dry cough, weight loss, chest pain, persistent cough)
Blastomycosis
incubation period for Blastomyces dermatitidis
3 weeks-several months
this causes blastomycosis
Blastomyces dermatitidis
where does Blastomycosis skin infection appear (enlarging raised lesion with ulcercating center)?
face, hands, wrists, feet, ankles
severe blood-borne Blastomycosis fungal lesions can occur here
bones, prostate gland, testes, kidneys
most common involvement of Blastomycosis
pulmonary and cutaneous
what parts of North America are affected by Blastomycosis (overlaps with histo)
Southeastern and south central states (follows Mississippi and Ohio rivers)
how long does it take Blastomyces dermatitidis to develop colony on culture medium (at 37C)
2 weeks
treatment for Blastomycosis
itraconazole, AmB, or fluconazole
