dimorphs (1) Flashcards
coccidiodes is thermally dimorphic, what are its two forms?
mold and spherule (all the others are mold and yeast)
where is coccidioides endemic? what type of weather does mold form grow in?
US southwest
wet weather
what form of coccidioides in infectious? what type of weather is this form released in?
infectious arthospores released in dry
60% of ppl have a “mild infection” with coccidiodes, describe the presentation
asymptomatic or flulike clearance by innate or containment by CMI
what organism causes valley fever/desert rheumatism?
coccidioides (moderate disease)
describe the severe form of an infection with coccidioides
major pneumonia or dissemination (either bare or in macrophages)
how do you treat someone with coccidioides infection that is predisposed to complications?
oral azoles
how do you treat coccidiodes meningitis
fluconazole
how do you treat someone who is prego or with a disseminated coccidiodes infection
amphotericin B
where is histoplasma endemic?
ohio, missouri and mississippi river valleys
what gets “kicked up by construction projects” that causes histoplasma infection
infectious microconidia
how does an immunocomptant person respond to histoplasma infection
usually clear or contain in granulomas, higher-dose infection produces TB like illness
how does a CMI deficient host respond to an histoplasma infection
dissemination in macrophages, look for pancytopenia and ulcerations on tongue
what is special about the histoplasma yeast?
they can survive in lysosomal fusion! (they can survive the acidic environment and not get killed in lysosomes)
how do you treat a serious lung infection with histoplasma?
itraconazole
how do you treat histoplasma meningitis?
fluconazole
how do you treat a disseminated histoplasma infection
amp B
where is blastomyces endemic?
eastern US
how does a moderate acute blastomyces infection appear?
pneumonia w/ purulent sputum
how does a moderate chronic blastomyces infection appear?
mimics TB
how does a severe acute blastomyces infection appear?
ARDS
what 3 dimorphic fungi will you see erythema nodosum lesions
blastomyces & coccidioides & histoplasma during inflammatory stage
what will culture of blastomyces look like?
hyphae with pear shaped conidia
what will a biopsy of blastomyces look like?
yeast with suppurating (NOT caseating) granulomas
where is paracoccidioides endemic?
rural latin american
how does a juvenille infection with paracoccidioides present?
lymphadenopathy and hepatosplenomegaly
how does an adult present with paracoccidiodes infection?
very long latency
skin&mucus lesions
how can you diagnose paracoccidiodes?
by puss or tissue KOH mount for multiple buds
describe the classic patient with paracoccidiodes (demographics)
adult man with hx of agriculture work, malnutrition, smoking, alcoholism with travel or from latin america
(this infection is slighly pathogenic)
describe the mold form of paracoccidiodes
thin, septate hyphae
describe the yeast form of paracoccidiodes
thick walled with multiple buds
what organism produces BAD1? what is this?
blastomyces
virulence factor that is a immune modulator on the cell surface
what agent is the most common form of systemic mycosis?
histoplasma
what are the 2 forms of histoplasma spores
- tuberculate macroconidia- thick wall
2. microconidia-infectious form with thin wall
are the spherules and endospores of coccidioides infectious?
no
