Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Pedo > Lecture 1: Oral ecology > Flashcards

Lecture 1: Oral ecology Flashcards

(78 cards)

Start Studying
1
Q

method for bacterial detection

A

16S sequencing, rDNA gene alignment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

how much of the oral cavity bacteria has been cultivated

A

more than half

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how many species of oral bacteria exist?

A

700 species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how many species of oral bacteria do individuals carry?

A

100-200 species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is the study of interrelationships of organisms and their environment?

A

ecology

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a niche?

A

specific combination of conditions that are necessary for the survival of particular organisms (chemical, physical, biological)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

where do microorganisms form stable, thick biofilms (plaque)?

A

non-shedding hard surfaces of teeth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how are periapical and odontogenic infections formed?

A

invasion of micro-organisms into soft tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

soft-tissue surfaces to which bacteria adheres:

A

sulcus, tongue, mucosa, gingiva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

hard tissue (supra) to which bacteria adheres:

A

fissures, proximal surfaces, buccal and lingual enamel surfaces, cementum, restorations, calculus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

hard tissue (sub) to which bacteria adheres:

A

enamel, cementum, restorations, calculus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

____ bacteria floats in water

A

planktonic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Bacteria that causes most dental problems and medical problems are _____, attach to the surface in biofilms

A

sessile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

biofilms are made up of ____and ____ in an ____

A

adherent microorganisms, extracellular matrix, aqueous enviornment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

3 steps of biofilm life cycle

A

1) attachment 2) growth 3) detachement to seed new biofilm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

T/F: biofilms can be formed from one species of bacteria

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

T/F: biofilms normal have many species of bacteria

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

biofilms can include other microorganisms such as:

A

fungi, algae, protozoa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Once bacteria attach to a surface, they ____

A

change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

biofilm-adaptive genes turn on when:

A
  • bacteria detect surfaces
  • bacteria detect each other (quorum)
  • signals pass between bacteria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

biofilm species co-exist and cooperate through:

A
  • provide nutrients
  • remove toxins
  • inter and intra cellular signalling
  • division of labor (metabolism)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

T/F biofilms are fast growing communities that are highly resistant to antibiotics, host defenses, and mechanical disruption

A

false, slow growing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

antibiotic dose to kill biofilm bacteria

A

1000x

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

3 mechanisms for biofilm antimicrobial resistance:

A

1) slow diffusion
2) persister cells alive but metabolicaly inactive survive and repopulate biofilm
3) close proximity and exchange of resistance genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
T/F most oral bacteria is planktonic
false
26
Saliva is the main precursor for biofilms
false
27
Biofilms cause oral problems such as:
- caries - periodontitis - osteomyelitis - osteonecrosis secondary to bisphosphonate therapy
28
T/F: preventing oral biofilms prevents some invasive diseases such as cellulitis
true
29
6 oral ecologic determinants for biofilm growth
1. surface receptors for adherence 2. oxygen tension (Eh) 3. pH 4. nutrients 5. host inhibitory factors 6. bacterial community interactions
30
what are surface sites to which bacteria adheres?
- receptor molecules - direct bacterial interactions - extracellular matrix
31
salivary binding promotes adherence by providing ____ or inhibits by ____ and _____
providing binding sites, agglutinating, clearing
32
components of saliva
- antibodies (aquired immunity) - salivary agglutinins - proline- rich glycoproteins - alpha-amylase
33
What is the electrical potential or tendency to oxidize or reduce?
oxidation-reduction potential (Eh)
34
Eh of aerobes?
positive
35
Eh of anaerobes?
negative
36
_____ require O2 at atmospheric levels for growth
obligate aerobes
37
____ can switch between aerobic and anearobic metabolism
facultative anaerobes (facultative aerobes)
38
____ require low levels of O2
microaerophilic
39
T/F aerotolerant anaerobes possess anaerobic metabolism but tolerate the presence of O2
true
40
to which class of microorganism is O2 toxic?
obligate anaerobes (aerophobes)
41
how is oxygen toxic to obligate anaerobes?
- causes oxidation of membrane lipids and destruction of cell integrity - causes oxidation of sulfhydryl groups in enzymes resulting in cross-linking and inactivity
42
which groups in enzymes are effected by oxygen leading to inactivity?
sulfhydryl groups
43
what 3 enzymes are anaerobes unable to make?
1) superoxide dismutase (SOD) 2) catalase 3) perroxidase
44
which oxygen products cause damage to cells?
superoxide and peroxide
45
superoxide dismutase, catalase, and peroxidase ____ oxygen radicals
detoxify
46
T/F the number of detoxifying enzymes in the cell determines the ability for them to exist in O2 enviroment
false, distribution
47
older plaque has a ___ Eh
lower
48
anaerobic species are found in?
sulcus or mature coronal plaque
49
facultative and microaerophilic specis found in?
supragingival plaque
50
what species scavanges O2 to provide anaerobic environment for other species (bridge)?
fusobacterium (F. nucleatum)
51
pH of soft drink
3
52
pH of fermentation product; lactate
5
53
pH in mouth ranges from ____ to _____
5 to 7.5 (periodontal pocket)
54
what are the nutrients of the supragingival environment?
saliva and ingested food
55
what are the nutrients of the subgingival environment?
crevicular fluid and cells
56
T/F carbs and aa's are readily taken up by bacteria
true, low MW
57
T/F protens and starches (sticky) are readily taken up by bacteria
false, must be retained
58
nutrients of saliva?
glycoproteins, inorganic salts, aa's, glucose, vitamins
59
components of gingival crevicular fluid?
serum proteins, aa's, glucose, vitamins, hemin, hormones
60
T/F endogenous nutrients are sufficient for plaque but not sufficient for caries
true, exogenous carbs are needed
61
what antibody prevents adhesion?
IgA
62
IgG acts by?
- inhibits colonization (block binding site/agglutingation) - act as opsonin - activate complement system
63
T/F neutrophils, complement proteins of crevicular fluid, and antimicrobial peptids (defensins, histatins, cathelicidins) are considered innate immune defenses?
true
64
T/F saliva is an innate defense
true
65
the major salivary protein that digests starches and binds bacteria and mucins is ______
alpha-amylase
66
salivary _____ digests peptidoglycan in cell wall leading to osmotic disruption and cell death
lysozyme
67
salivary ____ and ____ sequesters iron
lactoferrin and serum transferrin
68
what system produces superoxide radicals to inactivate bacterial enzymes?
sialoperoxidase system
69
T/F antimicrobial peptides have activity against bacteria and yeast
true
70
____ and ____ modulate salivary calcium and phosphate chemistry
acidic proline-rich proteins and statherin
71
lactate produced by streps is required by _____
veillonella
72
veillonella vonverts lactate to _____ to raise pH for acid-sensitive ____
propionate strep
73
vitamin K3 (menadione) is synthesized by _____ and used by _____ and _____
veillonella parvula, P. gingivalis, P. intermedia
74
carbon dioxide is generated by _____ and _____
peptostreptococci and eubacteria
75
carbon dioxide enhances growth of ____ and ____
capnocytophaga and actinomycetemcomitans
76
_____ removes oxygen to help species like _____ survive
F. nucleatum/periodonticum, taneralla forsythia
77
T/F strep salivarius produces enocin (bacteriocin) that inhibits S. pyrogenes
true
78
major oral niches/ecosystems
- supragingival tooth surface and dorsum of tongue | - gingival crevice

Pedo (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions