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Fungi Cell wall is made of
Chitin, Mannan, Glucan
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Fungi Cell membrane is made of
Sterol Ergosterol
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fungi capsule is made of
Mannan and glucan polysaccharides
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fungi reproduce by
sexual and asexual spores
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Some Fungi have the ability to form dfferent structures in different tempuratures(e.g. spores outside body and yesast inside) this is called
thermal dimorphism
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obligate aerobes, faculative anaerobes, obligate anaerobes which one does fungi not exhibit?
Obligate anaerobes
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fungi are eukaryotes or prokarytoes
eukaryotes
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prokaryotic, peptidoglycan cell wall, sterol absent cell membrane(mycoplasma), polysaccharide capsule, endospores for survival, no thermal dimorphism are charecteristic of
bacteria
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unicellular and multiply by budding
yeasts
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Cryptococcus species, and Candida species are
yeasts
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some buds(blastoconidia) elongate to form
pseudohyphae (resemble hyphae)
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molds structe are
multicellular filamentous
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branched filaments are called
hyphae
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hyphae can be divided into partitions called
septate or aseptate
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fungi exist as yeast in tissues at
37 degrees C
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Fungi exist as Mold or filamentous forms at
room temp 25 degrees celcius
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asexual spores are the
conidia (macro and micro) and sporangiospores
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shape color and arrangment of conidia aid in
identification of the fungi
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conidia are formed
externally on structures called conidiophores
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rectangular spores which arise from fragmentation of hyphae e.g. coccidoides immitis are
arthrospores
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round thick spores produced by candida albicans
chlamydospores
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buds of yeasts which sometimes do not detach and form long sausage shaped false hyphae; pseudohyphae
BLASTOSPORES
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RHIZOPUS, MUCOR reproduce by
sporangiospores which are produced internally within sporangium
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most fungi attach to host cell receptors by
mannoproteins
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fungal pathogenesis act via fungal toxins and
mycotoxins
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epithelial turnover, fatty acid content, ph of skin, normal bacterial flora, ph MUCOSAL SURFACE, cilia and macrophages of the mucous membranes of nasopharynx, innate immunity are
host resistance to fungal infection
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host response to systemic fungal infections result in a
granuloma
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inflammatory cell infiltrate and macrophages that phagocyte fungi, in a localised nodule that acts to contain the infection is a
granuloma
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key determinant in protection from fungal infection
T- Cell mediated immunity
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severe fungal infections is due to
compromised cell mediated immunity
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activation of t cell mediated immune results in
delayted type hypersensitivity to fungal antigens
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normal skin mediated immune response determined by
candida skin tests
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acute suppuration characterised by the precense of neutrophils seen in infections like
sporotrichosis, aspergillosis
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mycoses(fungal infection) phagocytosis by
neutrophils
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polysaccharide capsules of fungi (e.g. cryptococcus) is
antiphagocytic
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conditions conducive to fungal infections
disruptions of bodies physical chemical or physiologic barriers, immunosupression : loss od CD4 TH1 response, disruption of normal bacterial flora
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immunosupression : loss of CD4 TH1 response, leads to oppurtunistic infections by normal flora such as
candida albicans
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immunosupression: loss of CD4 TH1 response leads to susceptibility to environmental fungi such as
aspergillus
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disruption of normal bacterial flora happens via
antibiotics, radiation
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mycoses which involves the keratinised outermost layers of skin hair and nails
superficial mycoses
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mycoses which involve the keratin layer of epidermis and deeper layers of skin hair and nails
cutaneous mycoses
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mycoses which involve dermis subcutaneous tissues, muscels and fascio
subcutaneous mycoses
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mycoses disseminated infections
systemic mycoses
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mycoses generally occur in patients with compromised immune systems(chemotherapy), HIV infected individual
oppurtunistic mycoses
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polyenes are
amphotericin B, nystain
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binds to ergosterol, disrupts fungal membranes by punching holes in cytoplasmic membrane
Polyenes (amphotericin B, and nystain)
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polyenes used to fight
systemic mycoses, oppurtunistic mycoses, oral thrush
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Azole derivatives
miconazole, clotrimazole(topical), ketoconazole, fluconazole, itraconazole, voriconazole
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inhibit fungal ergosterol synthesis by binding to p450 enzymes (cytoplasmic membrane)
azole derivatives
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used to fight systemic and oppurtunistic mycoses
azole derivatives
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inhibits ergosterol synthesis via squalene epoxidase
allylamines( terbinafine)
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allylamines(terbinafine) used to treat
systemic & topical for dermatophytes
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nucleoside synthesis disruption via a nucleoside analog called
flucytosine
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inhibits dna and rna synthesis, covnerted to fluoracil and acts as an antimetabolite
nucleoside analog flucytosine
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nucleoside analog flucytosine used to treat
cryptococcus candida
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echinocandins are
caspofungin, micafungin
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inhibits glucan synthesis (cell wall synthesis)
echinocandins (caspofungin, micafungin)
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echniocandins (caspofungin & mycofungin) used to treat
candida and aspergillus
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other - inhibits fungal mitosis by interacting with microtubules, deposits in nails
grisans, griseofulvin
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grisans griseofulvis used to treat
cutaneous mycoses not responding to topical antifungal
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other- potassium iodide used to treat
therapeutic sporotrichosis
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