an introduction to fungi Flashcards
What is a fungus?
A chemo-organotrophic eukaryote that lacks chlorophyll and forms spores. Its cell wall contains polysaccharides, often chitin or glucan, and it absorbs nutrients. Its membrane contains ergosterol as the major sterol. Classification is principally based on morphology.
what are the three fungal pathogens of humans
Basidiomycetes
Ascomycetes
Zygomycetes
what kind of habit do yeast fungi favour?
unicellular
what is the Main dermatophyte virulence factor
enzyme(s) that degrade and utilize keratin as a nutrient source
Diseases caused by the dermatophytes
‘ringworm’ infections, usually called
tinea
what are the causitave agents of Dermatophytosis
Epidermophyton
Trichophytonspp
Microsporum
what are the causative agent of Pityriasis versicolor
Malassezia spp
true or false Aspergillus spp. Infect deep organs of patients undergoing
true
Host factors contribute to pathogenicity of fungal infections
favourable micro-environments (warm, moist areas) encourage growth of fungi on skin and mucous membranes
broad-spectrum antibacterial agents reduce competition for epithelial colonization sites in the gut
immunosuppression of all types may create a window of opportunity for fungal invasion
what are the two types of Immunosuppression of host defences
Iatrogenic
Disease processes
where can you get Candida infections
mouth, vagina, penis, skin, nails
how does Chronic mucocutaneous Candida infection arise
can arise in individuals with an unusual combination of endocrine and immune dysfunction
what are the causative species of Aspergillosis
Aspergillus fumigatus
Aspergillus flavus
Aspergillus nidulans (in CGD patients)
Aspergillus lentulus
what are the types of disease with Aspergillosis
simple asthma asthma with eosinophilia aspergilloma invasive bronchopulmonary aspergillosis disseminated aspergillosis
whats the route of infection of Aspergillosis
inhalation of conidia
true or false A. fumigatus infects by inhalation of conidia, which germinate to hyphae in the lung tissue.
true
where does A. fumigatus is angioinvasive invade
walls of blood vessels
what are the causative species of cryptococcosis
Cryptococcus neoformans
Cryptococcus gattii
what diseases does cryptococcosis
pulmonary cryptococcosis
meningitis (particularly in AIDS patients)*
disseminated infection in severely compromised hosts
what are the three anti fungal agents
Polyenes
Azoles
Echinocandins
