Normal Microbiota Flashcards
define colonisation
establishment at a site in the body
define microbiota
all the organisms in a given community
define microbiom
all the genes present within microbiota
what is symbiosis
two or more organisms living or co-existing in close physical association
what are the 4 types of symbiosis
mutualism - both organism benefit
neutralism - neither benefit nor harm
commensalism - one organism benefits the other derives no benefit or harm
parasitism - one rogasnim benefits at the expense of the other
how can non-sterile environments be contaminated
directly through the skin or indirectly such as through trachea or GI tract
how are sterile sites in the body kept that way with examples
surface cleaning - eg lower RT uses sputum to trap MO’s
OR barriers
OR physical operation (pleural cavity)
define tropism
propensity for an organism to grow in that particular habitat
what does a tropism depend on
moisture, temp, ph, O2, nature of surface
which microbes are normally found on the skin
staphylococcus epidermis/aureus and other coagulase negative staphylococcus
propionbacterum such as (acnes)
what kind of environment does the skin provide
variable temperature, dry, subject to abrasion, aerobic. nutrient poor
what kind of environment is gingival crevice
constant temp, moist, aerobic, lots of nutrients
what microbiom are present in gingival crevice
viridian’s streptococci
anaerobes (clostridium)
what relationships are there between the bacteria and host in the gingival crevice
mutualistic (both gain) and/or parasitic (one gain other loses)
what microbiom are usually present in the nose and pharynx
s. aureus (nose) pharynx - streptococcus pyogenes haemophilus influenza streptococcus pneumonia niesserira meningitis s.aureus
