Oral Bacteria Flashcards Preview

D1S U1 Microbiology > Oral Bacteria > Flashcards

Flashcards in Oral Bacteria Deck (15):
1

The oral cavity is dominated by this bacteria:

Streptococci
(S. Mitis- all of mouth.
S. Sanguinis and S. Gordonni- tooth surface)

2

Early (pioneer) oral colonizer. Binds pellicle thru surface adhesins, provides binding sites for late colonizers (co-aggregation), produces H2O2 (inhibits S. mutans)

Streptococci (S. mitis, S. sanguinis, S. oralis, S. gordonii)

3

Early (pioneer) oral colonizer. Metabolizes lactic acid

Veillonella

4

Early (pioneer) oral colonizer. Binds to pellicle, other early colonizers and late colonizers (co-aggregation)

Actinomyces

5

Late colonizer of oral cavity. Anaerobic but aerotolerant, co-aggregates, removes oxygen

Fusobacterium nucleatum

6

Late colonizer of oral cavity. Strict anaerobe, asaccharolytic

Porphymonas Gingivalis

7

Hypothesis that dental caries results from a perturbation in bacterial populations due to a disruption in the environment rather than a specific bacteria or infectious agent.

Non-specific plaque hypothesis

8

Etiological agent of dental caries. Mainly Serotype C in oral cavity.

Streptococcus Mutans

9

Virulence factors of Streptococcus Mutans:

1. Acidogenic (metabolizes carbs -> acid production)
2. Acid Tolerant- more tolerant than commensal bacteria
3. Glycosyltransferases- enzymes that form polymers of glucose from sucrose, liberating fructose
4. Glucan binding proteins

10

Three GTF (Glycosyltransferase) enzymes of S. mutans:

1. GtfB (Gtfl)- water insoluble glucan, alpha 1,3 linked
2. GtfC (GtfSl)- both water insoluble glucan alpha 1,3 linked and water soluble alpha 1,6-linked glucose
3. GtfD (GtfS)- water soluble alpha 1,6-linked glucose

11

Probiotics used to treat dental caries:

1. S. Oligofermentans- metabolizes lactic acid
2. S. Australis- raises plaque pH
3. S. Gordonii- Produces protease that degrades CSP

12

Glucan (EPS) production by S. mutans requires ____

Sucrose

13

Bacterial species most commonly associated with Periodontal Disease:

1. P. Gingivalis (Porphyromonas Gingivalis)
2. Tannerella Forsythia
3. Treponema Denticola

(All anaerobes, all part of Socransky's Red Complex)

14

P. Gingivalis:
1. Gram stain?
2. Oxygen Tolerance?
3. What does it ferment?
4. Why is it a keystone pathogen in periodontal disease?

1. Gram-negative
2. Obligate anaerobic
3. Amino acid (not sugar)
4. Causes disbiosis (inhibits host immune response, allowing bacteria to take over)

15

Periodontitis is caused by _____

Inflammation and build up of subgingival biofilm