Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

AU17: Oral Microbiology > Ecology And Microbial Diversity > Flashcards

Ecology And Microbial Diversity Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What are the traditional methods to detect bacterial species?

A
  1. Microscopy
  2. Cultivation
  3. DNA Methods
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the problem with microscopy in detecting bacterial species?

A

Difficult to distinguish similar morphotypes

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

What are some problems with cultivation in detecting bacterial species?

A
  1. Special nutrient requirements

2. Minor and slow growing species overgrown

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

T/F: Although many bacterial species have not been cultivated, more than half of oral cavity bacterial species have been cultivated.

A

True

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

How many species of bacteria are in each persons mouth?

A

Roughly 200 species

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

What does it mean that the mouth is an open system?

A

We have transient species vs true residents of the oral cavity that grow

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

T/F: Each of us has more human cells than bacterial cells.

A

FALSE

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

T/F: The mouth has different niches for various bacteria.

A

TRUE

Hard surfaces (teeth) have thick biofilms called plaque

Soft tissues are invaded by other organisms

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

What is a planktonic bacteria?

A

It floats in water

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

Most bacteria that cause dental problems are __________, meaning they attache to a surface in biofilms.

A

Sessile

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

The sticky material that holds a biofilm together is called the ___________.

A

extracellular matrix

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

T/F: Biofilms can include multiple bacteria as well as fungi, algae, and protozoa.

A

True

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

What causes bacteria to change and express different genes when in a biofilm?

A
  1. React to attached surfaces
  2. React to other bacteria (quorum sensing)
  3. Signals pass between bacteria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How do species co-exist and cooperate with each other?

A
  1. Provide nutrients for each other
  2. Remove toxins
  3. Inter- and intra-species signaling
  4. Create a “division of labor”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How do species within a biofilm compete with each other?

A
  1. Antimicrobial peptides
  2. Peroxide
  3. Lactic acid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

T/F: Biofilms are slow growing.

A

True

17
Q

T/F: Biofilms are resistant to antibiotics, host defenses, and mechanical disruption.

A

True

18
Q

T/F: It is appropriate to use antibiotics to fight biofilms.

A

FALSE

Would need to administer antibiotics in toxic doses to defeat biofilm bacteria

19
Q

What are the primary mechanisms for biofilm antimicrobial resistance?

A
  1. Slowing of diffusion
  2. Persister cells
  3. Exchange of resistance genes
20
Q

What are persister cells?

A

Alive but metabolically inactive cells meant to survive and repopulate biofilm

21
Q

T/F: Saliva provides a thick film of defense in the mouth.

A

False

Thin - only a few microns thick

22
Q

Why are anaerobes sensitive to oxygen?

A

They are unable to make enzymes such as superoxide dismutase, catalase or peroxidase.

Without these enzymes oxygen products (superoxide/peroxide) cause damage to the cell.

23
Q

What specific enzymes allow cells to live in the presence of oxygen?

A

Superoxide dismutase, catalase, and peroxidase

24
Q

If an environment has a low Eh, what type of bacteria are likely to be found there?

A

Anaerobes

Low Eh = low oxygen

25
Q

What bacteria scavenge O2, providing an anaerobic environment for other bacterial species?

A

Fusobacterium

26
Q

What are the two major physical nutrient niches in the oral cavity?

A
  1. Supragingival: saliva and food

2. Subgingival: GCF and cells

27
Q

T/F: Ingested food is a good nutrient source for subgingival bacteria.

A

FALSE

Supragingival only

28
Q

Although endogenous nutrients are sufficient for __________, in order for ___________ to develop there must be exogenous carbohydrates.

A

Plaque; caries

29
Q

What antibody in the saliva can prevent bacterial adhesion?

A

sIgA

30
Q

What antibody in the GCF can help prevent biofilm formation?

A

IgG

31
Q

What is the major salivary proteins that help inhibit biofilm formation?

A

Alpha-amylase and mucins

32
Q

What are two mechanisms for maintaining the integrity of the tooth?

A
  1. Pellicle proteins

2. Salivary buffering

33
Q

How are streptococci and Veillonella connected in a food chain?

A

Streptococci make lactic acid which is used by Veillenella to keep the pH high for strep

34
Q

Which bacteria use the vitamin K3 produced by Veillonella?

A

P. Gingivalis and p. Intermedia

35
Q

What bacterial product is generated by a number of organisms to enhance the growth of Capnocytophaga and A.a.?

A

Carbon dioxide

36
Q

How do “good” microbes inhibit buildup of the “bad” microbes?

A
  1. Inhibitory factors (bacteriocins)

2. Colonize niches before the bad can attach

37
Q

What are the six ecological determinants of bacterial adhesion and survival?

A
  1. Surface receptors
  2. Oxygen tension (Eh)
  3. pH
  4. Nutrients
  5. Host inhibitory factors
  6. Bacterial community interactions

AU17: Oral Microbiology (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions