Fungi Flashcards
(11 cards)
Coccidioides immitis
Fungi
Dimorph
Special features: mold in soil, spherules + endospores in host
Epi: arid areas
Transmission/pathogenesis: inhalation of spores –> spores turn into spherules in lung, elicit cellular immunity, hematogenous dissemination with granulomas
Signs/symptoms: acute self-limited flu-like seroconversion syndrome (“Valley fever”), acute/chronic lung disease, dissemination in skin, bone, CNS
Sporothrix schenckii
Fungi Dimorph Special features: soil Disease: sporotrichosis Epi: gardeners Virulence factor: spores Transmission/pathogenesis: splinter or thorn inoculates spores into subQ tissues, yeast travels via lymphatics Signs/symptoms: ulcerating nodules along hard cord, septic arthritis Treatment/notes: Itraconazole
Blastomyces dermatitidis
Fungi Dimorph Special features: soil Epi: humid woodlands virulence factor: spores Transmission/pathogenesis: inhalation of spores --> spores turn into yeast in lung, disseminate Signs/symptoms: acute to chronic cavitary/nodular lung disease, can disseminate to skin, bone, UTI/prostate Unique dx methods: no good antigen test
Histoplasma capsulatum
Fungi
Dimorph
Special features: thermally dimorphic
Disease: RTI
Epi: guano of bats, birds
Virulence factor: spores
Transmission/pathogenesis: inhalation of spores –> spores turn into yeast in lung, elicit cellular immunity, hematogenous dissemination with granulomas
Signs/symptoms: mimics TB, acute/chronic cavitary lung disease, can be latent and activate years later
Unique dx methods: microscopy, pathology/culture, urinary antigen
Dermatophytes (microsporum, epidermophyton, trichophyton spp.)
Fungi
Mold
Special features: narrow hyaline hyphae
Disease: skin infections
Transmission/pathogenesis: grow as saprophytes on skin/nails, cause inflammation below
Signs/symptoms: tinea corporis, tinea pedis, tinea capitis, tinea cruris, tinea unguium; active border, no mucosal involvement
Unique dx methods: KOH preparation, UV fluorescence
Treatment/Notes: Allylamines (terbinafine, naftifine) are fungicidal
Aspergillus fumigatus
Fungi
Mold
Special features: narrow, septate, branched hyphae
Disease: Aspergillosis
Transmission/pathogenesis: spores get inhaled, elicit allergy, invade vasculature and disseminate
Signs/symptoms: allergic bronchopulmonary aspergillosis, aspergilloma, invasive aspergillosis with pneumonia, emboli
Treatment/notes: Voriconazole and posaconazole
Mucorales spp.
Fungi
Mold
Special features: nonseptate hyphae, no yeast phase
Disease: Mucormycosis
Transmission/pathogenesis: Normally not virulent, but becomes so in acidosis, diabetes, PMN dysfunction, Fe overload
Signs/symptoms: acute, fulminant, often fatal pneumonia progressing to infarction or sinusitis progressing to brain abscesses
Treatment/notes: Amphotericin B, Posaconazole
Malassezia furfur
Fungi
Yeast
Special features: commensal
Disease: tinea versicolor, fungemia, dandruff
Transmission/pathogenesis: livs on skin, eating skin lipids
Signs/symptoms: pigment changes, itches underneath
Pneumocystis jiroveci
Fungi Yeast Special features: extracellular Disease: pneumocystis pneumonia (PCP) Epi: HIV Transmission/pathogenesis: mostly seen in cell-mediated immunity defects (CD4 < 200) Signs/symptoms: abrupt onset fever, cough, dyspnea, may be more insidious if AIDS Treatment/notes: mortality 25%
Candida spp.
Fungi
Yeast
Special features: hyphal forms; Gram positive
Disease: Candidiasis, invasive candida infection
Virulence factors: hydrolases, beta proteases, phospholipases
Transmission/pathogenesis: commensal to vagina, nasopharynx; change in environment or immunity triggers infection
Signs/symptoms: can cause meningitis, endocarditis, microabscesses almost anywhere in body
Treatment/notes: fluconazole, nystatin, voriconazole, posaconazole
Cryptococcus neoformans
Fungi
Yeast
Special features: India Ink (+)
Disease: cryptococcus, cryptococcal meningitis
Epi: pigeons
Virulence factor: polysaccharide capsule
Transmission/pathogenesis: inhalation of yeasts
Signs/symptoms: acute/chronic pneumonia +/- meningoencephalitis, communicating hydrocephalus
Unique dx methods: ring on India ink stain of CSF, antigen assay
