Host Microbe Interactions Flashcards
what is a pathogen
a microbe capable of causing host damage/disease
what is an opportunistic pathogen
organism that is part of the resident microbiota but can cause infection under certain circumstances
what does symbiont mean
member of resident microbiota and confers BENEFIT to the host
what does pathobiont mean
member of resident microbiota that causes disease when dysbiosis occurs (loss of normal balance between the host and resident microbiota)
what does dysbiosis mean
imbalance between the host and resident microbiota
OR
our response to the imbalance
give examples of ecological stress that can lead to dysbiosis
host defences
diet
hormones
exogenous species
how is homeostasis maintained
- negative feedback
2. antagonistic and synergistic interactions
all microorganisms rely on nutrients from either endogenous or exogenous sources. give examples of exogenous sources of nutrients
diet
- fermentable carbohydrates= acid production, polymer synthesis
- diary products= milk (casein)
- alternative sweeteners= sorbitol, xylitol, saccharin
endogenous sources of nutrients for microorganisms
saliva
- aa
- peptides, proteins
- vitamins
- glycoproteins
- gases
GCF
- albumin
- proteins
- glycoproteins
- haem
what are some examples of extracellular polymers
sucrose which is broken into :
glucan (glucosyltransferases)
fructan (fructosyltransferase)
glucosyltransferase is a virulen factor of which bacteria species
s. mutans
what is catabolism
break down of large inorganic molecules to smaller units
what is anabolism
construction of large molecules from smaller units
oral bacteria may be sacchrolytic or assachrolytic. what is the difference between these
sacchrolytic= break down sugars to make acid assachrolytic= break down proteins/ peptides to make acid
which bacteria can convert glucose to lactate
streptococcus
