EX2 Leys

Question 1

This is a mixture of microbes and a matrix made up of extracellular polymers

Answer 1

biofilm

Question 2

What do you find in complex structures within a biofilm

Answer 2

bacteria

Question 3

True or False

Most biofilms are mixtures of different species of bacteria

Answer 3

True

Question 4

True or False

Biofilms can include other micro-organisms than bacteria

Answer 4

True

Question 5

Biofilms have complex structures that do what

Answer 5

give accessibility to nutrients and removal of waste products

Question 6

True or False

Bacteria in a biofilm are more resistant to antibiotics and host attacks

Answer 6

True

Question 7

Most bacteria form biofilms in an environment where there is what

Answer 7

liquid flowing

Question 8

Wild bacteria have extracellular polymers attached to their surface that allow what

Answer 8

binding to surfaces or other bacteria

Question 9

Biofilms are associated with what dental diseases

Answer 9

periodontal disease

caries

Question 10

Many bacterial diseases involve what type of species

Answer 10

polymicrobial

Question 11

What is the type of communication between bacteria

Answer 11

quorum sensing

Question 12

What are the two general mechanisms for quorum sensing

Answer 12

recognizes similar bacteria (same species)

recognizes all bacteria

Question 13

True or False

Essentially all bacteria have mechanisms for quorum sensing

Answer 13

True

Question 14

When do quorum sensing mechanism produce a response

Answer 14

when a certain threshold concentration of secreted molecules is reached

Question 15

This is an essential process in biofilm formation

Answer 15

quorum sensing

Question 16

This type of bacteria must have oxygen to grow

Answer 16

strict aerobes

Question 17

This type of bacteria cannot tolerate oxygen

Answer 17

obligate anaerobes

Question 18

This type of bacteria can grow with or without oxygen

Answer 18

facultative anaerobes

Question 19

DNA that enters a bacterial cell can undergo what three things

Answer 19

be degraded
integrated into the host chromosome
integrated into plasmid

Question 20

These are used by bacteria to degrade foreign DNA

Answer 20

restriction endonucleases (restriction enzymes)

Question 21

This is the uptake of naked DNA by “competent cells”

Answer 21

transformation

Question 22

This is the transfer of DNA between bacteria through a virus

Answer 22

transduction

Question 23

This is the transfer of DNA through cell to cell contact using a sex pilus

Answer 23

Conjugation

Question 24

Mutations in DNA can cause this

Answer 24

antibiotic resistance

Question 25

This type of mutation is less likely to cause antibiotic resistance

Answer 25

deletion

Question 26

Bacteria remove oxygen radicals from cells how?

Answer 26

by converting them to hydrogen peroxide with superoxide dismutase

Question 27

Hydrogen peroxide is converted to what

Answer 27

converted to water and oxygen with a catalyst

Question 28

Bacteria that do not have superoxide dismutase and catalase are what

Answer 28

anaerobic | they do not tolerate oxygen

Question 29

These are the most numerous members of the normal flora of the human colon

Answer 29

bacteroides

Question 30

This disease is a result of spillage of intestinal material into the peritoneal cavity

Answer 30

biphasic disease | acute inflammation followed by localized abscesses

Question 31

This is the most common isolate from intra-abdominal abscesses

Answer 31

bacteriodes fragilis

Question 32

This on the surface of B. fragilis is not toxic, unlike other gram negative bacteria

Answer 32

LPS

Question 33

Of the hundreds of different species of bacteria that may spill into the peritoneal cavity, this will help the bacteria evade phagocytosis of the host

Answer 33

a polysaccharide capsule

Question 34

Intra-abdominal abscesses caused by B. fragilis or other bacteria can lead to this

Answer 34

bacteremia | septic shock

Question 35

This is the presence of bacteria in the blood, with out without the presence of an illness

Answer 35

bacteremia

Question 36

This is a severe systemic illness marked by hemodynamic derangement and organ malfunction

Answer 36

sepsis

Question 37

The treatment of sepsis with antibiotics is important but can be difficult because of this

Answer 37

the dead bacteria can release toxins that initially cause more damage

Question 38

These are widespread in nature, but few cause disease

Answer 38

spirochetes

Question 39

The corkscrew-like movement of spirochetes is facilitated by what

Answer 39

a periplasmic flagella

Question 40

This is the causative agent of syphilis, and is difficult to study because it cannot be grown in the lab

Answer 40

treponema pallidum

Question 41

When T. palladium enters the body, it becomes systemic almost immediately, how?

Answer 41

by traveling via the lymphatic system to system circulation

Question 42

The primary chancre (painless ulcer) formed by T. palladium heals (spontaneously/with treatment), and the infection (is/is not) systemic

Answer 42

spontaneously | is

Question 43

What percentage of patients who do not receive treatment for primary syphilis enter the secondary stage of syphilis

Answer 43

50%

Question 44

True or False | The rash produced by secondary syphilis is often mistaken for other problems

Answer 44

True

Question 45

Tertiary syphilis, if left untreated, can progress where and cause what

Answer 45

to the CNS | causing ataxic gait, paresis, blindness, dementia, and death

Question 46

True or False | Syphilis is one of the hardest STDs to control

Answer 46

False; it is one of the easiest to control; there are good diagnostic tests and treatment is available and inexpensive

Question 47

This is the causative agent of Lyme's disease

Answer 47

Borrelia burgdorferi

Question 48

Lyme's disease progresses in stages to from what to what

Answer 48

from an acute and local skin infection to a chronic disease of the CNS and joints

Question 49

B. burgdorferi is transmitted by what

Answer 49

ticks

Question 50

There are how many different bacterial species found in the oral cavity, from many different phyla

Answer 50

500-1000

Question 51

True or False | You can find all the different types of bacteria everywhere in the mouth

Answer 51

False; different bacteria occupy different environmental niches

Question 52

Subgingival bacteria are generally what | Supragingival bacteria are generally what

Answer 52

``` subgingival = proteolitic supragingival = saccrolitic ```

Question 53

These factors promote colonization in the oral cavity

Answer 53

adherence properties synergistic bacteria nutritional substrates temperature/moisture content

Question 54

These factors inhibit colonization in the oral cavity

Answer 54

antimicrobial properties of saliva mechanical shearing temperature/moisture content

Question 55

True or False | There are many bacteria associated with periodontitis, while there are fewer species associated with periodontal heath

Answer 55

True

Question 56

Shifts in microbial composition occur in periodontitis, however no bacterium is what

Answer 56

found on all patients with periodontitis and never found in healthy subjects

Question 57

The tissue destruction that occurs during periodontitis is a result of what

Answer 57

host response

Question 58

There is a small shift of what bacteria during periodontitis

Answer 58

from gram positive to gram negative

Question 59

The complexity of the microbial community (increases or decreases) during periodontal disease

Answer 59

increases

Question 60

There is a slight shift to more what bacteria in periodontal disease

Answer 60

uncultivated

Question 61

True or False | Microbial diversity declines in caries

Answer 61

True

Question 62

True or False | There is progression of dominant species as caries progresses

Answer 62

True

Question 63

Each location in the oral cavity has its own associated microbial composition, and there (is/is not) any overlap of species

Answer 63

is overlap of species