Oral Bacteria

Question 1

where communities of bacteria are located in the mouth is determined by:

Answer 1

• binding sites
• oxygen level
• redox potential
• nutrients
• antagonism
• co-aggregation

Question 2

nutrient source, pH, and redox potential in fissues

Answer 2

• saliva and diet
• neutral-acidic
• positive

Question 3

nutrient source, pH, and redox potential in approximal surfaces

Answer 3

• saliva, diet, and gingival crevicular fluid (GCF)
• neutral-acidic
• slightly negative

Question 4

in gingival crevice:

Answer 4

• GCF
• neutral-alkaline
• negative

Question 5

where are anaerobic gram-negative rods found

Answer 5

the most in the gingival crevice, then in the approximal surfaces, and none/hardly any in the fissures

Question 6

____ is found in every location in the mouth

Answer 6

S. mitis

Question 7

____ and ____ are ubiquitously found on the tooth surface

Answer 7

s. sanguinis; s. gordonnii

Question 8

____ group streptococci dominate the oral cavity and are pioneer colonizers

Answer 8

mitis

Question 9

mitis group is major species in plaque (80%) and contains:

Answer 9

s. sanguinis
s. gordonnii
s. oralis

Question 10

____ group is the minor species in healthy plaque and contains:

Answer 10

mutans; contains s. mutans and s. sobrinus

Question 11

early (pioneer) colonizers include:

Answer 11

1. streptococci (s. mitis, s. sanguinis, s. oralis, and s. gordonii)
2. veillonella
3. actinomyces

Question 12

4 virulence factors of s. mutans

Answer 12

1. acidogenic
2. acid tolerant
3. glycosyltransferases
4. glucan binding proteins

Question 13

acidogenic virulence factor

Answer 13

s. mutans has the ability to metabolize dietary carbohydrates and produce acid

Question 14

acid tolerant VF

Answer 14

ATR (acid tolerance response)- more tolerant to acidic environment than commensal bacteria

Question 15

glycosyltransferases (GTF)

Answer 15

extracellular enzymes that form polymers of glucose from sucrose, liberating fructose

Question 16

glucan binding proteins (Gbp)

Answer 16

surface proteins that bind glucan

Question 17

s.mutans metabolizes carbohydrates, producing:

Answer 17

lactic acid
acetic acid
formic acid
which then lowers the pH

Question 18

GTFs produce ____ from _____

Answer 18

extracellular polysaccharide (EPS); sucrose

Question 19

____ is associated with cariogenic plaque formation- binds everything together when ____ is present

Answer 19

water insoluble glucan; sucrose

Question 20

bacteria that make up socransky’s red complex

Answer 20

1. porphyromonas gingivalis (anaerobe)
2. Tannerella forsythia (anaerobe)
3. Treponema denticola (anaerobe)

Question 21

characteristics of P. gingivalis

Answer 21

• gram negative rods
• obligate anaerobe
• asaccharolytic (ferments aa not sugar)
• requires iron to grow (hemin)