Week 4: Microbiology & Immunology Flashcards
non-pathogenic bacteria that live in harmony with host
commensal, innocuous (“innocent”) bacteria
removal forces of bacteria
swallowing, mastication, blowing nose, wash-out effect by saliva, cilia motion
six major ecosystems
- intraoral hard surfaces (teeth, implants, etc.)
- subgingival tissue next to hard tissue
- oral mucosa surfaces
- tongue?
- throat?
- saliva
soft tissues are ___ sites
shedding
shedding sites are ___ biomass sites
low
teeth are ____ sites
non-shedding
non-shedding sites are ____ biomass sites
high biomass
T/F, edentulous persons are immune to bacterial infections
false, they are still susceptible
tongue is ____ for gram negative species
favorable
saliva is ___% water, protective in nature, and washes away ___ cells include ___ bacteria transmission
98%, shed, planktonic
free-floating bacteria in salvia suspension
planktonic
true or false? periodontal pocket provides accommodating environment for bacterial survival
true
thick, single celled wall
gram positive
bacteria that stains purple/blue
gram positive
double celled wall
gram negative
bacteria that stains red
gram negative
probiotic bacteria for colon cancer prevention
roseburia
bacteria found in fermented foods
bifidobacterium bifidum
bacteria found in fermented foods, helps prevent infections and disorders
lactobacillus acidophilus
is lactobacillus acidophilus gram positive or gram negative?
gram positive
is bifidobacterium bifidum gram positive or gram negative?
gram positive
is aggregatibacter actinomyectemcomitans (A. a) gram positive or gram negative?
gram negative
bacteria harmful in periodontitis prevention
aggregatibacter actinomyectemcomitans
which bacteria are more susceptible to antibiotics?
gram positive (they do not block)
which bacteria have a higher peptidoglycan component?
gram positive
gram negative have a higher ___ content, making them less permeable
lipid
cell surface appendages that adhere cell-cell or cell-surface
fimbriae (pili)
cell surface appendages used for movement
flagella
gram positive
- _______
- break down complex organic compounds (____) to ____ ___ for energy/growth
- fermentable
- sugar to lactic acid
gram negative
- ______
- use ___ for energy/growth
- nonfermentable
- proteins
attached bacteria make up more than ___% of all bacteria
99%
free-floating bacteria
planktonic bacteria
a well-organized community of bacteria that…
- adheres to surfaces
- is embedded in an extracellular slime layer
biofilm
biofilms exist everywhere in nature, on any solid surface that is exposed to _________
bacteria-containing fluid
true/false, biofilm can accumulate on dentures, bridges, implants, etc.
true, they can!
biofilms forms a ___, mushroom-shape microcolonies
sessile
true/false, chemical signals exist to communication between bacterial microcolonies
true, they do
bacteria communicate with each via…
quorum sensing
process of plaque formation
- formation of pellicle
- initial adhesion/attachment of bacteria
- colonization/maturation
salivary glycoproteins (mucins) adhered to tooth surface
acquired pellicle
thin base of acquired pellicle = ____ to remove; thicker is ____ to remove
difficult, easier
first bacteria to attach
streptococcus, actinomyces
as bacteria shifts subgingival, bacteria becomes ___ ____
gram negative
key WBCs
polymorphonuclear neutrophils (PMNs)
is the extracellular slime layer aerobic or anaerobic?
both
is the EC slime layer resistant or nonresistant to antibiotics/antimicrobials?
it is resistant, needs to be physically remove
an increase of ____x concentration to kill bacteria in EC slime layer, which is ___
500-5,000x, unsafe
t/f, the EC slime layer is responsive to the body’s defense system
false, it is not. EC slime layer needs to be physically removed
functions of EC slime layer
- protects biofilm from host response
- protects form antibiotics
- protects anaerobic/aerobic bacteria
- holds bacterial colonies
microcolony formation is _____ _____
secondary colonization
bacteria become more static in the _______ state
mushroom-shaped
corn cob appearance of plaque occurs at __ weeks
three
floss, rinse, mouthwash cannot reach beyond __ mm pockets
4mm pockets
3 zones of subgingival plaque
- tooth-attached plaque
- epithelial-attached plaque
- unattached plaque
there are variations in _____ formation in growth due to ___, ___, ____, ____
variations; diet, smoking, salivary flow, oral hygiene
variations in dentition such as ___, ____, ____
mandible, molars, interproximal
timeline of periodontitis bacteria
increase in plaque, inflammation, increase in GCF, increase in plaque
GCF stands for ______ and is a marker for ____-
gingival crevicular fluid; periodontitis
bacterial virulence factors
- ability to invade tissues
- endotoxins
- bacterial enzymes
two types of endotoxins
leukotoxins, lipopolysaccharides (LPS)
component of cell walls of gram negative bacteria, released at cell death
lipopolysaccharide (LPS)
bacteria proportions associated with health
75-80% gram positive, most nonmotile, streptococcus mutans dominated
bacteria proportions with gingivitis
50/50 gram positive and gram negative, more actinomyces-dominated
bacteria associated with periodontitis
high proportion of gram-negative, non-motile
4 types of periodontitis bacteria
A. a.; fusobacterium nucleatum; T. forsynthus; porphyromonas gingivalis (Pg)
bacteria associated with aggressive periodontitis, makes star shape on agar plate
actinobacillus actinomycetemcomitans (Aa)
bacteria found in early stages of periodontitis, present subgingivally, capable of early inflammatory
fusobacterium nucleatum
bacteria most important risk factors for aggressive periodontitis, found deep subgingival in deep periopockets
tannerella bacteroides
bacteria associated with periodontitis, capable of destroying bone & entering junctional epithelium, can be found in aggressive and states of health
porphyromonas gingivalis (Pg)
key transmission of periodontal pathogens
kissing
