Fungal Pneumonia Flashcards
3 yeast pathogens
candida, PJP, crypto
2 mold pathogens
aspergillus, mucor/rhizopus
3 dimorphic pathogens
blastomyces, histoplasma, coccidiodes
2 branching bacteria
nocardia, actinomyces
structure of candida
budding yeasts and/or pseudohyphae
*germ tube formation at 37 degrees in culture for Dx, looks kinda like sperm
candida infection
usually extrapulmonary - mucocutaneous or blood
rare pulm infections in neutropenic pts
candida Rx
requires isolation from biopsy, use echinocandins or ampho B
structure of crypto
heavily encapsulated, ring around it on culture
crypto infection
most commonly meningitis
pulm sx are non specfiic
if either meningitis or pneumonia is found, need to look for the other
dx and rx for crypto
direct visualization in india ink, culture, antigen detection
rx w/ ampho B and flucytosine
shape of PJP
disc shaped years in lungs, hamburger like
PJP and HIV
can have extrapulm infection in late AIDS
strongly associated w/ HIV
PJP outcomes
worse in those immunocompromised by something other than HIV
PJP dx and rx
diffuse interstitial pneumonia (ground glass) on CXR, direct visualization from lung tissue/sputum/BAL
silver stain!
rx w/ SMX/TMP (bactrim), not antifungals
shape of aspergillus
septate hyphae w/ acute angle branching
aspergillus associations
heme malignancies
sinusitis, brain abscess, catheter infections, ABPA (in asthmatics)
aspergillus infections
aspergilloma/fungus ball in lungs, forms cavity and causes hemoptysis
dx and rx of aspergillus
direct tissue observation
rx w/ voriconazole
shape of mucor/rhizopus (zygomycetes)
aseptate hyphae w/ wide angle branching
zygomycetes infection
necrosis following angioinvasion: rhinocerebral, GI, cutaneous
pulm infection- prolonged fever, airway obstruction, hemoptysis
dx and rx for zygomycetes
direct tissue observation
rx w/ ampho b
shape of histoplasma
oval yeast inside tissue macrophages
mold form in cold/ lab- budding around circular organism
histoplasma infection
fungal homologue to Mtb- high exposure causes cavitary lesions
dx and rx of histoplasma
direct observation in tissue/culture, urine antigen
rx w/ itraconazole or ampho B when serious
shape of blastomyces
thick walled yeast, broad based budding in extracellular spaces
blasto infection
can go anywhere- commonly skin, bones, joints
acute pulm looks bacterial but doesnt respond to antibiotics, can progress to ARDS
chronic pulm looks like Tb and histo
dx and rx of blasto
direct obs in tissue or culture
rx even for asymptomatic, itraconazole or ampho B
coccidioides shap
spherules w/ endospores in tissue, barrels in environment
coccidioides infection
often disseminated to skin, lymph nodes, bones
erythema nodosum (desert bumps)
lung nodules or cavities
dx and rx of coccidioides
direct observation in biopsy or culture, skin test
rx w/ fluconazole or ampho B for persistent/ disseminated disease
describe actinomyces
filamentous G+ anaerobe, normal oral flora
actinomyces infection
oral/facial abscesses (sulfer granules), PID w/ IUD
rarely bronchopulm, looks like cancer or TB
dx and rx of actinomyces
direct obs in tissue or biopsy
rx w/ penicillin
describe nocardia
beaded filaments, G+ and weakly acid fast (less than Tb), aerobe, found in soil
nocardia infection
brain abscess in immunocompromised, pulm disease w/ pneumonia or lung abscess w/ cavities
dx/rx for nocardia
direct obs, culture
rx w/ bactrim