Flashcards in Introduction to Fungi Deck (24)
classification of fungi
principally based on morphology. Three major types:
an infection of the skin caused by moulds with a predilection to degrade keratin as a nutrient source.
fungi that cause dermatophytosis (ringworm/tinea)
-epidermophyton (epidermophyton floccosum)
-microsporum (microsporum canis)
-trichophyton (trichophyton mentagrophytes)
caused by malassezia spp. causes discoloured blotches on skin.
what do Candida spp. infect?
infect deep organs of patients with various types of immune dysfunction.
which patients are susceptible to aspergillus spp. infections?
infect deep organs of patients undergoing treatments such as chemotherapy and stem cell transplantation
Candida infections (candidiasis, candidosis)
cause a wide range of infections:
what type of fungi is candida?
aspergillus infections (aspergillosis)
-asthma with eosinophilia (high levels of eosinophils)
-invasive bronchopulmonary aspergillosis
aspergillosis causing spp.
what type of fungi are aspergillus spp. ?
In what type of patients do disseminated infections occur?
seriously immunocompromised patients
main causative species for cryptococcosis
describe the properties of fungi
chemo-organotropic eukaryote that lacks chlorophyll and forms spores.
host factors that contribute to pathogenicity of fungi
-favourable micro-environments encourage growth of fungi on skin and mucous membranes
-broad spectrum antibacterial agents reduce competition for epithelial colonization sires in gut
-immunosuppression of all types may create a window of opportunity for fungal invasion
diagnostic methods for identifying fungal infections
-direct detection (histopathology, high-res CT scans
-detection of circulating fungal antigens
-detection of circulating antibodies to fungi
-PCR for fungal DNA
-culture of fungi form normally sterile sites
mechanisms of action for antifungal drugs
-cell walls (echinocandins)
-cell membrane (polyenes)
-target DNA synthese (flucytosine)
-target sterols (triazoles and allylamines)
issues with antifungal agents
toxicity- drugs may be toxic to patient
resistance- fungus may develop resistance to drug
cost- treatments can be expensive
target cell wall
target cell membrane
target dna synthesis