Leyes Study Guide

Question 1

A ___ is a mixture of microbes and a matrix made up of extracellular polymers.

Answer 1

biofilm

Question 2

Bacteria form complex structures within a ___.

Answer 2

biofilm

Question 3

Most biofilms are mixtures of different ___.

Answer 3

species of bacteria

Question 4

Biofilms can include other ___ than bacteria.

Answer 4

micro-organisms

Question 5

Biofilms have complex structures that give accessibility to ___ and removal of ___.

Answer 5

nutrients

waste

Question 6

Bacteria in a biofilm are more resistant to ___ and ___.

Answer 6

antibiotics and host attack

Question 7

Most bacteria form biofilms in an environment where there is ___.

Answer 7

liquid flowing

Question 8

Wild bacteria have ___ attached to their surface that allow them to bind to surfaces or other bacteria.

Answer 8

extracellular polymers

Question 9

Biofilms are associated with many diseases including ___ and ___.

Answer 9

periodontal disease and caries

Question 10

Many bacterial diseases (including oral infections) are ____ where several species are involved.

Answer 10

polymicrobial

Question 11

___ is the communication between bacteria

Answer 11

quorum sensing

Question 12

There are two general mechanisms for quorum sensing; one the recognizes ___ bacteria and one that recognizes all bacteria.

Answer 12

same species

Question 13

Essentially all bacteria have mechanisms for ___.

Answer 13

quorum sensing.

Question 14

Quorum sensing mechanisms produce a response when a certain ___ of secreted molecules is reached.

Answer 14

threshold concentration

Question 15

Qurum sensing is an essential process in ___

Answer 15

biofilm formation

Question 16

Strict ___ must have oxygen to grow. ___ cannot tolerate oxygen and ___ can grow with or without oxygen.

Answer 16

Strict aerobes
obligate anaerobes
facultative anaerobes

Question 17

___ that enters a bacterial cell can be degraded, integrated into the host chromosome or integrated into a ___.

Answer 17

DNA

plasmid (extrachromosomal element)

Question 18

Restriction ___, or restriction enzymes, are used by bacteria to degrade foreign DNA

Answer 18

endonucleases

Question 19

___ is the uptake up naked DNA by “competent cells”

Answer 19

transformation

Question 20

___ is the transfer of DNA between bacteria through a virus

Answer 20

transduction

Question 21

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

Answer 21

conjugation

Question 22

___ in DNA can cause antibiotic resistance. They can be the result of base changes, deletions, insertions, duplications, or rearrangements

Answer 22

mutations

Question 23

___ are less likely to cause antibiotic resistance.

Answer 23

deletions

Question 24

Bacteria remove ___ from the cell by converting them to hydrogen peroxide with superoxide dismutase. This is then converted to water and oxygen with ___.

Answer 24

oxygen radicals

catalase

Question 25

Bacteria that do not have superoxide dismutase and catalase are ___.

Answer 25

anaerobic

Question 26

__ are the most numerous members of the normal flora of the human colon.

Answer 26

bacteroides

Question 27

Spillage of intestinal material into the peritoneal cavity typically results in a ___: acute inflammation followed by localized abcesses.

Answer 27

biphasic disease

Question 28

There are a large number of bacterial species present during the ___ with only a few species that predominate in abcesses.

Answer 28

acute phase

Question 29

___ is the most common isolate from intra-abdominal abscesses

Answer 29

bacteriodes fragilis

Question 30

Of the hundreds of species that are introduced into the peritoneal cavity by spillage from the colon, those (including B. fragilis) that have a ___ survive by phagocytosis by the host.

Answer 30

polysaccharide capsule

Question 31

Intra-abdominal abcesses caused by B. fragilis or other bacteria can lead to ___ and ___.

Answer 31

bacteremia and septic shock

Question 32

The ___ on the surface of B. fragilis is not toxic unlike other gram negative bacteria.

Answer 32

LPS

Question 33

___ is the presence of bacteria in the blood, with or without the presence of an illness.

Answer 33

bacteremia

Question 34

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

Answer 34

sepsis

Question 35

Treatment of ___ with antibiotics is important but can be difficult because the dead bacteria can release toxins that initially cause more damage.

Answer 35

sepsis

Question 36

___ are widespread in nature, but few cause disease.

Answer 36

spirochetes

Question 37

The corkscrew-like movement of spirochetes is facilitated by a ___.

Answer 37

periplasmic flagella

Question 38

___, the causative agent of syphilis, has sen difficult to study because it cannot be grown in the lab.

Answer 38

Treponema pallidum

Question 39

When T. palladum enters the body, it becomes systemic almost immediately by traveling through the ___ to the systemic circulation.

Answer 39

lymphatic channels

Question 40

The primary ___ formed by T pallidum heals spontaneously, but the infection is already systemic

Answer 40

chancre

Question 41

About ___% of patients who do not receive treatment enter the secondary stage of syphilis.

Answer 41

50%

Question 42

The rash produced by ___ is often mistaken for other problems

Answer 42

secondary syphilis

Question 43

Tertiary syphilis, if left untreated, can progress to the ___, causing ataxic gait, paresis, blindness, dementia, and death.

Answer 43

CNS

Question 44

Borrelia burgdorferi is the causative agent of ___.

Answer 44

Lyme's disease

Question 45

Like syphilis, Lyme's disease progresses in stages from an acute and local skin infection to a chronic disease of the ___ and ___.

Answer 45

CNS and Joints

Question 46

B. burgdorferi is transmitted by ___.

Answer 46

ticks

Question 47

There are ___ bacterial species found in the oral cavity, from a wide variety of phyla

Answer 47

500-1000

Question 48

Different bacteria occupy different environmental niches. ___ bacteria are generally proteolitic. ___ bacteria are generally saccrolitic.

Answer 48

subgingival | supragingival

Question 49

Factors that promote colonization in the oral cavity include ___ properties, ___ bacteria, nutritional substrates and temperature and moisture content.

Answer 49

adherence properties | synergistic

Question 50

Factors that inhibit colonization in the oral cavity include ___ properties of saliva, mechanical shearing, and ___ bacteria

Answer 50

antimicrobial | antagonistic

Question 51

There are many bacterial species that are associated with ___, while fewer species are associated with periodontal health

Answer 51

periodontitis

Question 52

Shifts in microbial composition occur in ___, however no bacterium is found in all patients with ___ and never found in healthy subjects.

Answer 52

periodontitis | periodontitis again

Question 53

The tissue distraction that occurs during periodontitis is mainly the result of a ___

Answer 53

host response

Question 54

There is a small shift from gram ___ to gram ___ during periodontitis

Answer 54

positive | negative

Question 55

the complexity of the microbial community ___ during periodontal disease

Answer 55

increases

Question 56

There is a slight shift to more ___ bacteria in periodontitis

Answer 56

uncultivated

Question 57

Microbial diversity declines in ___ and a progression is seen in terms of the dominant species is it progresses.

Answer 57

caries

Question 58

Each location in the oral cavity have its own associated microbial composition. however there is some overlap

Answer 58

.