Caries, Micro Dev & Biofilms Flashcards
what kind of growth does planktonic growth undergo
vegetative
what is planktonic growth
single bac suspended in media
- rich or nutrient limiting
ideal conditions
what is th density growth of planktonic growth
low to high usually exponential
classic growth phase, lag, exponential, stationary and decline
what is the limited contact/ co aggregation impact on planktonic growth
cells should sep individually
starvation can sec material or alter growth to form raft and develop biofilm
what si the series of events in planktonic growth
planktonic bac approach surface contact & attach adherence and changes cell surface metab activity changes enviro quorum seeing and dev mature biofilm = new planktonic cells
what is F nucelatum involved in
plaque
perio disease
still birth
cancer
what is one of key issues in plaque
adhesive surface able to adhere
auto aggregation
what is the sensory input fro prokaryotic dev
starvation
high pop density
what is the response/enters dev pathway
biofilm form
competence
motility and chemotaxis
endospore form
give an example of developmental pathway
transition of planktonic growth to biofilm
what is quorum sensing
population density
what does b subtilise do
create spores
what gene influences biofilm formation
EzrA
what is the b subtilise cycle growth
dormant spore germination vegetative stare sporulation lyse spore again
what is the control of gene expression dept on
dna binding protein
sigma factor
RNA polymerase
what s the phosphorelay of B subtilis
a system for integrating environmental signals into entering developmental pathway
what does networks of coordinated sigma factors result in
spore formation
what is a biofilm
name given to microbial communities attached to a surface
complex ago of bac
wha are the properties of a typical biofilm
spatially organised in a 3D Structure
bac cells enclosed in ECM
inc habitat range of indiv bac
what are he purpose of a biofilm
cooperation behaviour
protection
microenvironment
structure
what does a biofilm do in terms of habitat
extends habitat range
what are the developmental stages of oral biofilm
pellicle form attachment growth of individual bac microbial succession and diversification climax community
what re the key features assc with biofilm
cells switched away from planktonic growth matrix ECM subs nutrient gradients void spaces diff and dev inter sp assc
what is quorum sensing
process in which single celled organisms monitor their pop density by detecting the conc of small and diffusible signal mols produced by cells themselves
what are some gm -ve and gm +ve
gm -ve - N acetyl homoserine lactones
gm +ve - oligopeptides
what re some plaque formations
corn cob complex
cauliflower complex
hedgehog complex
what is the sp plaque hypothesis
caries down to a limited NO of bac
what si the non sp plaque hypothesis
caries outcome of overall activity of microbes
what its the ecological plaque hypothesis
no sp mix of microorgs at a lesion
enviro change shifts proportion of subset of bac
what is a causative situ fro caries
high?frequent sugar intake favours acidgmenic?acidoduric bacteria
do all surfaces covered by biofilm = caries
no
what are some prevention strategies
oral hygiene diet fissure sealing fluoride nutrient control control of biofilm pH control redox potential novel strategies
