Palmer Flashcards
S. pyogenes virulence factors (6)
- M protein
- Hyaluronic acid (HA) capsule
- Hyaluronidase
- Streptolysin S and O
- Erythrogenic toxins
- Streptokinase
Function of S. pyogenes M protein
- Bind to keratinocytes
- Prevents opsonization by complement
M protein of s. pyogenes binds to … and inhibits alternative complement pathway
fibrinogen
M. protein of S. Pyogenes binds to…. and inhibits formation of opsonins by complement cascade
Complement control protein
Streptokinase binds…
plasminogen
Plasmin coated group A strep can degrade and spread through fibrin resulting in
invasive disease
The 6 different locations in the mouth that bacteria live
- fissures
- saliva
- supra gingival plaque
- loosely attached biofilm
- sub gingival plaque
- mucosal surfaces
Locations on bacteria in the mouth are determined by….
- binding sites
- oxygen level
- redox potential
- nutrients
- antagonism
- co-aggregation
oral cavity is dominated by
streptococci
… is found in every location in the mouth
s. mitis
… and… are ubiquitously found on the tooth surface
S. sanguinis and S. gordonnii
the …. group is the major species in plaque
Mitis (sanguinis, gordonni, oralis)
The…. group is the minor species in plaque
Mutans (mutans and sobrinus)
Fusobacterium nucleatum, porphymonas gingivalis, treponema denticola, and prevotella are all….
late colonizers
Streptococci (mitis, sanguinis, oxalis and gordonii), Veillonella and Actinomyces are all…
early pioneer colonizers
Fusobacterium is an…., congregates with many species, and removes…
- anaerobe
- O2 (NADH oxidase/peroxidase)
Dental caries results from a perturbation in bacterial populations due to a disruption in the environment rather than a specific bacteria is the …. hypothesis
non-specific plaque hypothesis
The lag phase is the time when bacteria… and the genes
- adapts to environment
- are turned on to begin metabolism of nutrients
- (beginning of graph)
The exponential phase is when the bacteria
grows logarithmically (middle of graph)
The stationary phase where growth stops/decreases because…
nutrients are exhausted or toxic by-product buildup
Chromosomal DNA is supercoiled in a…
nucleiod structure
DNA gyrase function
introduces supercoils
Topoisomerase I function
relaxes supercoils
3 steps to chromosomal replication
- initiation- depends on growth rate
- elongation
- termination
DNA replication is…. and…
bidirectional
semi-conservative
Semi-conservative means that each daughter DNA contains…
half new and half old DNA
The oral cavity is dominated by… the…. group
streptococci
mitis
…. is found in every location in the mouth
S. mitis
… and … are ubiquitously found on the tooth surface
S. sanguinis and S. gordonnii
The 3 species in the Mitis group that are the major species in plaque are
sanguinis
gordonnii
oralis
The mutans group (minor species in healthy plaque) are comprised of these 2 species
mutans
sobrinus
… is the etiological agent of dental caries
streptococcus mutans
Serotypes of S. mutans, c, e, f, and k are based on the …. on cell wall
ramose-glucose polysaccharide
The 4 virulence factors of streptococcus mutans
- acidogenic
- acid tolerant
- glycosyltransferases (GTF)
- glucan binding proteins (Gbp)
80% of isolates from oral cavity are serotype….
c
The red complex (associated with periodontal disease) is made up of…
- Porphyromonas gingivitis
- Tannerella forsythia
- Treponema denticola
(all anaerobes)
P. gingivalis requires… to grow
iron
P. gingivalis are gram…. rods
negative
P. gingivalis is an obligate…
anaerobe
P. gingivalis is… which means it produces NH3 increasing pH and ferments amino acids, not sugar
Asaccharolytic
S. mutans is acidogenic which means it has the ability to…
metabolize dietary carbs and produce acid (lactic, acetic, formic)
3 characteristics of acid tolerant response by S. mutans
- Up regulation of F1F0 ATPase
- Glycolytic enzymes are more acid tolerant
- modifies membrane (less permeable to protons)
Glycosyltransferases (GTF) produce extracellular polysaccharide (EPS) from…
sucrose
S. mutans has 3 GTF enzymes…
GtfB
GtfC
GtfD
Periodontal disease is caused by …
- subgingival biofilm
- inflammatory response
- high GCF, raised pH
- anaerobic proteolytic biofilm
Group B streptococci is the leading cause of … and…
neonatal sepsis and meningitis
Enterococci cause mostly… but is…
- nosocomial opportunistic infections
- worlds toughest pathogenic bacteria
Enterococci is tough because it can grow in…. and is inhibited(not killed) by… and is resistance to…
- high salt concentrations
- penicillin
- most antibiotics
Antibiotic synergism is required for effective killing of Enterococci, usually … and an…
penicillin and an aminogylcoside
…. is the most common cause of subacute bacterial endocarditis
Viridans (greening) streptococci
