Intro to fungi Flashcards
Sabrobes
live on dead or decaying, symbionts are association with mutual advantage, commensals is where one benefits and the other is neither harmed nor benefitted and parasites live on or within a host and are harmful to the host.
yeasts
unicellular, typically round/oval ASEXUAL repro through budding, pseudohyphae
Moulds
multicellular, filamentous/tubular hyphae (septate or aseptate or coenocytic). Sexual or Asexual repro spores.
true hyphae
permanence, differentiation, branching, arthrospores and chlamydiospores.
Mycelium
intertwined mat of hyphae, vegetative are like the roots and are attached to substrate/penetrate to obtain substrate. Reproductive ae the arial structures (asexual reproduction propagules (conidia
Aspergillus sp
always in mycelial phase even in deep tissue infections
Torula sp.
exist only as yeast.
KOH procedure
take scraping from margin, place on slide add KOh add 1 drop of lactophenol cotton blue so you can get rid of other
fungal gram stain
appear gram positive.
fungi do not have
structures of locomotion or capsules (except crytpococcus neoformans.
fungal cell wall.
no peptidoglycan, aminoglucan Chitin, also had beta glucan
cytpolasmic membrane of fungic contains
ergosteral, not cholesterol.
4 pathogenic eumycota
zygomycotina, ascomycotina, baidomycotina, deutormycotina.
Zygomycotina
most primitive, bread molds, non-septate, reproduce sexually and asexually (sporangium) opportunistic pathogen. examples Rhizopus, Mucor sp. water molds.
Ascomycotina
septate, asexual(conidia) sexual spores (ascospores) includes yeasts moulds, dermatophytes, some aspergillus
Basidomycotina
septate, produce sexual spores (basidiospores) includes mushrooms and puffballs, filobasidiella neoformans.
Deuteromycotina
fungi imperfecti- septate, reproduce asexually, sexual reproductive structures unknown- epidermophyton, microsporium, Tricophyton, Candida.
all fungi grow
axenically without others and all are aerobic or facultative and most are not capable of invading living human tissue.
they extend at the tip through apical growth with continuous protoplasm movment into tip. this provides prenetrating power and fresh nutrients. Hyphae–>
Free living state
myceliel or hyphal form, at ub phsyiological temperature and there are distinct sexual froms displayed
oblitgate aerobes
have catalase ans superoxide dismutase, require 1 atmospher(20%)
Microaerophiles
grow in presenceof O2 but only 4% if toxic ROS increase enzyme systems are overloaded and it inhibits growth, has only superoxide dismutase.
Obligate anaerobes
lack ROS removing enzymes,
factultateve anaerobes
grow in presence or absence of O2; Aerobic respiration, fermentation but best under aerobic conditions ex. Enterobacteriacea has both catalase and superoxid dismutase.
fungi(moulds) are normally
aerobic
yeasts are normally
facultative anaerobes
Aw. for yeasts and bold.
0.60(osmophilic yeasts), for most yeasts .95-.85, for most moulds .7-.8 , for xerophilic moulds .55-.7
autotroph
CO2 the sole or principle form of C source
Heterotroph
reduced/preformed organic molecules and other organisms.
chemotrophs
oxidation(organic or inorganic)
Lithotrophs
reduced inorganic moleculs
organotrophs
organic molecules
most pathogens are
chemoorganotrphoic heterotrophs.
all purpose medium
supports growth of most mircoroganisms, has nutrient agar, and broth, trypitcase soy broth
enriched media
basal growth support media plus nutritive supplements added(blood agar)
reduced medium
addition of reduction agent to remove O2 (cystine, thioglycolate, ascorbate) so that anaerobes can grow.
Selective medium
allows one species to grow and suppresses others. you can do this by adjusting pH, specific C or energy source, increase osmotic pressure or adjust O2 tension, (slamonella shigella agar, mannitol salt agar
differential meidum
more than one type of organism can grow but serparation is based upon visible changes in the media and distinquishes between various genera.
media can be both
selective and differential or enriched and differential
fungal cultivation
selective isolation on Sabouraud’s agar using peptone and a pH of 5.6 with antibiotics of penicillin, sterptomycin, tetracycline.
corn meal agar
used for culture and species ID, incubated at 25* for several days until sexual structures develop to ID.
fungal toxins
A. fumigatus- Gliotoxin that inhibits macrophage phagocytosis, T-cell activation and induces apoptosis. A. flagvus- aflatoxin, carcinogenic
