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Cards in this deck (15)
- 1What are fungi?Genetically complex opportunistic pathogens which are able to shift and adapt to host environments
- 2What are commensal fungi and give two examples of theseCandida albicans and tricosporon. Commensal fungi are normal microbiota that normally live in the gut but a change in the gut microbiota which favors them can lead to a breakout
- 3Which patients are most at risk of fungal infections?1. HIV infected patients
2. Cancer patients
3. Bone marrow transplant patients
4. Solid organ transplant patients
All of the above are immunocompromised - 4What is a dimorphic fungus and give two examplesDimorphic fungi are able to switch from a yeast (in the blood) to a filamentous form which is able to invade tissues. Candida species and Histoplasma capsulatum are examples of dimorphic fungi
- 5Which patients are most affected by invasive pulmonary aspergillosis?Those with hematological malignancies - i.e. often occurs in patients with chronic myeloid leukaemia
- 6Outline the pathogenesis of a fungal pathogen- Invasive candida are inhaled - lodge in the respiratory tract
- Swell and if not suppressed by macrophages, germinate
- Fungal hyphae form which are normally blocked by neutrophils (unless the patient is neutropenic)
- Fungal hyphae invade tissues before disseminating and invading the blood - 7List 4 constituents of a fungal cells wallBeta 1,3 glucan, Beta 1,6 glucan, Chitin and Ergosterol
- 8What is the role of the Dectin-1 receptor and where is this found?Dectin-1 is found on dendritic cells and some macrophages. It mediates the binding of fungal glucans via C-type lectin carbohydrate recognition domain. Binding of fungal glucans to Dectin-1 leads to tyrosine phosphorylation of ITAMS which activates various downstream signalling pathways
- 9Which receptor type does dectin-1 work synergistically with?Toll-like receptors
- 10What enables syk and ZAP-70 tyrosine kinases to bind to phosphorylated tyrosine residues of ITAMSTheir precisely spaced SH2 domains
- 11Which TLR works synergistically with mincle to increase the activity of phagocytic cells?TLR-2
- 12What is the role of Pam3CSK4 in the treatment for fonsecaea pedrosoi?If immune cells are just challenged with fonsecaea, this does not result in much of an immune response. Pam3CSK4 is given to protect against microbial activity and acts as a TLR-2 agonist, which when F.pedrosoi is also bound to mincle, results in a synergistic effect of the two receptors, leading to a large increase in cytokine production (TNF-a)
- 13Give an example of a nonsocomial infectionThrush caused by candida albicans. Colonised oral, GI tract and urogenital mucosa
- 14What do the surface adhesion molecules and mannoproteins on the surface of candida activate?The alternative and lectin complement pathways. i.e. CRD's of MBL recognise mannose carbohydrates, leading to activation of MASPS which initiate the lectin complement cascade. MBL is a collectin, which acts as an opsonin, marking the invading fungi/bacteria for destruction
- 15What is the result of the interaction between fungal wall mannoproteins and dectin-1?Increased IL-2, IL-6 and TNF-a release (inflammatory cytokines)
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- Flashcards on Untitled, created by jp385 on 29/11/2014.
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