Periodontal Pathogens Flashcards Preview

AU 15- Periodontology > Periodontal Pathogens > Flashcards

Flashcards in Periodontal Pathogens Deck (68):
1

What is the "non-specific plaque hypothesis"?

Direct correlation between the amount of plaque and the amount of inflammation because all bacteria are considered bad. By this hypothesis, plaque control is important in perio treatment

2

What is the "specific plaque hypothesis"?

There is not a direct 1:1 correlation between amount of plaque and inflammation because only certain bacteria are considered bad. Disease sites differ from healthful sites because specific organisms are the etiological agents.

3

What is the "ecological plaque hypothesis"?

How the body reacts to bacteria will push the environment and ecology toward specific organisms. For example, plaque accumulation causes inflammation which will lead to an environmental change (more GCF flow) and then an ecological shift will occur that better supports anaerobic and gram negative organisms.

4

What is the theory of Oral Dysbiosis?

Bacteria may have more than one role in manifestation of disease; the capability of bacteria causing damage directly depends on the presence of other cells for nutrients or modulation.

5

What are the three prerequisites for disease initiation and progression?

1. The virulent periodontal pathogen (exhibiting virulence)
2. The local environment
3. Host susceptibility

6

What is the surface protein in P.gingivalis that distinguishes healthy vs disease types?

fimA
I and V = healthy
II and IV = perio

7

What is "niche saturation"?

colonization by beneficial species of bacteria which dilutes levels of pathogenic species

8

______ can increase outer membranes protein (OMP) expression in P.gingivalis and lead to _______.

Iron
Inflammation

9

What are four methods of pathogenic colonization?

1. Adhesins on bacteria (bind to host receptors)
2. Coaggregation
3. Nutrient Utilization (symbiosis)
4. Competitive Inhibition (hydrogen peroxide production)

10

How can a pathogen overcome the hosts desquamation of epithelium (defense mechanism)?

By invading and binding to underlying cells

11

How can a pathogen overcome antibodies that prevent binding?

By mimicking host antigens

12

How can a pathogen evade phagocytic cells of the host?

Through non-lethal suppression of immune cells and release of toxins (leukotoxin by A.a)

13

Which three periodontal pathogens were designated in 1996 as relating to disease?

P. gingivalis
A. actinomycetemcomitans
T. forsythia

14

In the color-coding system for subgingival microbial complexes: how are red, orange, and yellow complexes distinguished?

Red-Complex: bacteria consistently related to disease
Orange: probably pathogenic bacteria
Yellow: health compatible bacteria but could be pathogenic

15

Which three bacteria are strongly associated with periodontal disease?

Actinobacillus actinomycetemcomitan (A.a)
Porphyromonas gingivalis (P.g)
Bacteroides forsythus (B.f)

16

T. denticola and F.nucleatum are considered to be periodontal pathogens with _______ evidence of pathogenicity.

moderate

17

True or False: A.a is non-motile.

True

18

Is A.a gram positive or gram negative?

negative

19

What is characteristic about A.a colonies?

A.a forms star shaped colonies

20

A.a is ________, meaning that it metabolizes sugars for energy.

saccharolytic

21

What are the five considerations in determining pathogenicity of an organism?

1. Association
2. Elimination
3. Host Response
4. Virulence Factors
5. Animal Studies

22

Describe evidence for A.a pathogenicity in regard to Koch's five postulates.

1. Association: A.a detected in active sites and high numbers are associated with aggressive perio
2. Elimination: elimination results in successful therapy
3. Host Response: high level antibody response
4. Virulence Factors: Tissue invasive collagenase, leukotoxin, endotoxin, Fibroblast inhibiting factor
5. Animal Study: induces disease in animal models

23

What are some arguments against A.a as an etiological pathogen in perio?

Not seen in all cases
Seen in healthy cases
Specific strains of A.a could be associated with health

24

There are ______ serotypes of A.a that are based on ______ on the surface of the organism.

five
polysaccharides

25

Which serotype of A.a is most commonly associated with disease?

B

26

Treatment for removal of A.a requires a _______ AND ______ approach.

mechanical
chemotherapeutic (reduce bacterial load)

27

Which of the following is not a virulence factor of A.a: leukotoxin, collagenase, lipoteichoic acid, lipopolysaccharide.

Lipoteichoic acid (teichoic acid is associated with gram +)

28

Which has higher levels of murein, gram negative or gram positive?

Gram positive

29

Which has an outer membrane, gram positive or gram negative?

Gram negative

30

Which has a thick, multilayer of peptidoglycan, gram positive or negative?

Gram positive

31

Which contains teichoic acid in its cell wall, gram positive or gram negative?

Gram positive

32

P. gingivalis is gram ______.

negative

33

A.a has ______ and _____ which induce apoptosis.

leukotoxin
LPS

34

P. gingivalis is non-motile and forms characteristic ______ bacteroides in culture.

Black Pigment

35

True or False: P. gingivalis grows on iron (blood) and forms black pigmented colonies.

True

36

__________ in P.gingivalis are important for protein degradation and maturation of cell surface proteins such as fimA.

Cysteine proteinases (ARG-gingipain, LYS-gingipain)

37

What are the two important cysteine proteinases in P.gingivalis?

ARG-gingipain
LYS-gingipain

38

A.a is saccharolytic; P.gingivalis is _______.

asaccharolytic

39

Which virulence factors does P.g produce?

collagenase
protease
hemolysin
endotoxin
NH3 and H2S
indole

40

True or False: P.g is a primary colonizer.

False

41

The presence of P.g indicates an increased risk for ______.

attachment loss (strong association=evidence as pathogen)

42

Even in a diseased state, P.g does not exist in high numbers in which oral environment?

the subgingival community= only 0.3%

43

Fimbriae, hemagluttinins, OMPs, and vesicals are involved in ______ and ______ of P.gingivalis.

colonization and attachment

44

Proteases, LPS, and antiphagocytic products are P.gingivalis characteristics involved in ________.

evading host responses

45

Which two proteins are involved in P.gingivalis multiplication?

proteinases and hemolysins

46

_____ and _____ gingipains (proteinases) are involved in host damage by P.gingivalis.

Arg-
Lys-

47

Tannerella forsythia is a gram ______ pathogen that requires _____ for growth.

negative
N-acetymuramic acid (NAM)

48

Which pathogen does T. forsythia co-cultivate with?

F. nucleatum

49

Which virulence factor on the surface of T. forsythia will mediate adhesion and allow hemagglutination?

its serrated "S-layer"

50

T. forsythia and T. denticola are part of the ______ complex.

Red

51

Which perio bacteria in the red complex will exist as spirochetes?

T. denticola

52

T. denticola is gram _____.

Negative

53

True or False: Like the other red complex organisms, T. denticola is non-motile.

False- T.d is HIGHLY MOTILE

54

What is T. denticola's "claim to fame"?

It was first identified in Acute Necrotizing Ulcerative Gingivalis (ANUG)

55

In addition to P.gingivalis, _______ forms black pimented baceriodes.

Prevotella nigrescens/ P. intermedia

56

P.nigrescens is gram _____ and grows extremely well in high levels of ______.

negative
naphthoquinone and estrogen

57

Which bacteria is associated with puberty and pregnancy-related gingivitis?

P. nigrescens (estrogen and naphthoquinone)

58

Sites with P.nigrescens (P.intermedia) show persistent ______.

BOP

59

Fusobacterium nucleatum is gram ______ bridging organism.

negative

60

Which bacterial species is the most common isolate cultured from subgingival microbiota in both health and disease?

F. nucleatum

61

F. nucleatum releases _______, elastase, and ______ from leukocytes.

cytokines
oxygen radicals

62

Which organism is found MOST often in both remission and progression of adult periodontitis?

F. nucleatum (but its still higher in disease than health)

63

True or False: There are several gram positive species of bacteria that are associated with disease.

True

64

True or False: There are several gram negative species of bacteria that are associate with health.

True

65

True or False: Niche saturation helps to maintain a healthy biofilm.

True

66

Are chairside microbial tests good indicators of disease?

No, because the presence of particular bacteria does not give conclusive evidence for disease state

67

_______ concept: promotes control of diseases before all other treatments.

Cross-infection

68

Name a small, anaerobic, gram-POSITIVE bacterial species.

P.micros