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SP14 Microbiology > EX2 Leys > Flashcards

Flashcards in EX2 Leys Deck (63):
1

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

biofilm

2

What do you find in complex structures within a biofilm

bacteria

3

True or False
Most biofilms are mixtures of different species of bacteria

True

4

True or False
Biofilms can include other micro-organisms than bacteria

True

5

Biofilms have complex structures that do what

give accessibility to nutrients and removal of waste products

6

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

True

7

Most bacteria form biofilms in an environment where there is what

liquid flowing

8

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

binding to surfaces or other bacteria

9

Biofilms are associated with what dental diseases

periodontal disease
caries

10

Many bacterial diseases involve what type of species

polymicrobial

11

What is the type of communication between bacteria

quorum sensing

12

What are the two general mechanisms for quorum sensing

recognizes similar bacteria (same species)
recognizes all bacteria

13

True or False
Essentially all bacteria have mechanisms for quorum sensing

True

14

When do quorum sensing mechanism produce a response

when a certain threshold concentration of secreted molecules is reached

15

This is an essential process in biofilm formation

quorum sensing

16

This type of bacteria must have oxygen to grow

strict aerobes

17

This type of bacteria cannot tolerate oxygen

obligate anaerobes

18

This type of bacteria can grow with or without oxygen

facultative anaerobes

19

DNA that enters a bacterial cell can undergo what three things

be degraded
integrated into the host chromosome
integrated into plasmid

20

These are used by bacteria to degrade foreign DNA

restriction endonucleases (restriction enzymes)

21

This is the uptake of naked DNA by "competent cells"

transformation

22

This is the transfer of DNA between bacteria through a virus

transduction

23

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

Conjugation

24

Mutations in DNA can cause this

antibiotic resistance

25

This type of mutation is less likely to cause antibiotic resistance

deletion

26

Bacteria remove oxygen radicals from cells how?

by converting them to hydrogen peroxide with superoxide dismutase

27

Hydrogen peroxide is converted to what

converted to water and oxygen with a catalyst

28

Bacteria that do not have superoxide dismutase and catalase are what

anaerobic
they do not tolerate oxygen

29

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

bacteroides

30

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

biphasic disease
acute inflammation followed by localized abscesses

31

This is the most common isolate from intra-abdominal abscesses

bacteriodes fragilis

32

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

LPS

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

a polysaccharide capsule

34

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

bacteremia
septic shock

35

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

bacteremia

36

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

sepsis

37

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

the dead bacteria can release toxins that initially cause more damage

38

These are widespread in nature, but few cause disease

spirochetes

39

The corkscrew-like movement of spirochetes is facilitated by what

a periplasmic flagella

40

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

treponema pallidum

41

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

by traveling via the lymphatic system to system circulation

42

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

spontaneously
is

43

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

50%

44

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

True

45

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

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

46

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

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

47

This is the causative agent of Lyme's disease

Borrelia burgdorferi

48

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

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

49

B. burgdorferi is transmitted by what

ticks

50

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

500-1000

51

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

False; different bacteria occupy different environmental niches

52

Subgingival bacteria are generally what
Supragingival bacteria are generally what

subgingival = proteolitic
supragingival = saccrolitic

53

These factors promote colonization in the oral cavity

adherence properties
synergistic bacteria
nutritional substrates
temperature/moisture content

54

These factors inhibit colonization in the oral cavity

antimicrobial properties of saliva
mechanical shearing
temperature/moisture content

55

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

True

56

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

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

57

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

host response

58

There is a small shift of what bacteria during periodontitis

from gram positive to gram negative

59

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

increases

60

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

uncultivated

61

True or False
Microbial diversity declines in caries

True

62

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

True

63

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

is overlap of species