Brainscape's Knowledge GenomeTM

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


See full index

MBIO 3010 > Section 16 - GI Tract Infections > Flashcards

Section 16 - GI Tract Infections Flashcards

1
Q

What is one of the leading causes of diarrhea diseases?

A

E. coli

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

What is needed for a GI tract infection to occur?

A

Pathogen must be ingested in sufficient numbers of possess attributes to elude the host defences of the upper GI tract and reach the intestine

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

What is the difference between true food poisoning and food-associated infections?

A
  • True food poisoning is ingestion of a pre-formed toxin

- Food-associated infections are when the food is the vehicle for the pathogen

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

Is true food poisoning or food-associated infections more fast acting and why?

A

True food poisoning because the pathogen is already available, whereas food-associated infections require the pathogen to multiply after it enters the body

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

What are 2 common causes of food-associated infections?

A

Campylobacter and salmonella

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

What are the 3 different ways that a pathogen can cause disease in the GI tract?

A

1) Alter the water and electrolyte balance in the small intestine, leading to massive fluid secretion
2) Cell destruction and inflammation
3) Penetrate intestinal mucosa so it can spread and multiply outside the bowel

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

What is the most common outcome of GI tract infections?

A

Diarrhea

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

Which groups is diarrhea the most severe in resource-rich countries?

A
  • Very young
  • Elderly
  • Immunocompromised
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Is the identity of the pathogen common in diarrhea cases?

A

No

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

What are the 6 groups of E. coli that cause diarrhea?

A

1) Enteropathogenic E. coli (EPEC)
2) Enterotoxinogenic E. coli (ETEC)
3) Enterohaemorrhagic E. coli (EHEC)
4) Enteroinvasive E. coli (EIEC)
5) Enteroaggregative E. coli (EAEC)
6) Diffuse-aggregative E. coli (DAEC)

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

What does EPEC generally cause?

A

Sporadic cases in babies and young children

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

Does EPEC produce toxins?

A

No

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

What are the virulence factors of EPEC?

A

Adhesins and bundle-forming pili and intimin for attachment to epithelial cells and microvillus

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

Which groups of E. coli are the most important contributors to global incidence of diarrhea?

A

EPEC, ETEC, and EHEC

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

What is the virulence factor of ETEC?

A

Binds to receptors on cell membrane of small intestine

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

What toxins does ETEC produce?

A
  • Heat labile (LT) toxin - similar mode of action as cholera toxin
  • Heat stable (ST) toxin - increases cGMP which increases fluid secretion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which group of E. coli is the most important in resource-rich countries?

A

EHEC

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

How can you contract EHEC?

A

From uncooked meat or contaminated water

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

What toxins does EHEC produce?

A

Verotoxin 1 and 2 also called “shiga like toxin”

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

What are the symptoms of EHEC infection?

A
  • Damage to large intestine

- Ulceration and bleeding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the most common serotype of EHEC?

A

O157:H7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What can EHEC infection lead to?

A
  • Hemorrhagic colitis

- Hemolytic uremic syndrome

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

What is hemorrhagic colitis?

A

Destruction of mucosa, leading to a hemorrhage which causes bloody diarrhea

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

What causes hemolytic uremic syndrome?

A

Toxin gets absorbed in the bloodstream and then the verotoxin receptors are found on renal epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the symptoms of EHEC infection?

A
  • Anemia (fatigue, weakness, light-headedness)
  • Low platelet count
  • Sudden kidney damage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Where does EIEC attack?

A

Mucosa of large intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

How does EIEC cause disease?

A

Invade cells by endocytosis, then multiply and spread to adjacent cells causing tissue destruction and inflammation and ulceration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is important about EAEC?

A

“Stacked brick” appearance on tissue culture cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How is E. coli diagnosed?

A

Specific tests to identify strains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How is EHEC diagnosed?

A

Identification of shiga toxin genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How is EIEC diagnosed?

A
  • Invasion of tissue culture cells

- Presence of invasion associated genes

32
Q

What is the treatment of E. coli?

A
  • Fluid replacement

- Antibacterial therapy not normally used

33
Q

Are antidiarrheal medications normally used and why?

A

No because increased contact time of the pathogen with intestinal wall leads to increased disease severity

34
Q

What is the treatment for HUS?

A

Dialysis

35
Q

How can E. coli infection be prevented?

A
  • Clean water
  • Pasteurization
  • Proper cooking
36
Q

What does salmonella cause?

A
  • Gastroenteritis and food poisoning

- Enteric fever

37
Q

What are the sources of salmonella?

A

Meat, poultry, eggs, and dairy products

38
Q

What are the symptoms of salmonella and when do they normally occur?

A
  • Nausea, vomiting, and diarrhea

- 6-48 hours after ingestion

39
Q

What does salmonella typhi lead to?

A

Typhoid fever

40
Q

How is salmonella typhi spread?

A

Fecal contamination of food or water

41
Q

What are the initial symptoms of typhoid fever?

A
  • Headache
  • Fever
  • General malaise
  • Abdominal tenderness
42
Q

When does diarrhea begin during typhoid fever?

A

When the pathogen reaches the gallbladder and peyer’s patches

43
Q

How does salmonella typhi cause chronic colonization?

A

Hides in gallbladder and biliary tree

44
Q

What is the most common cause of bacterial gastroenteritis in North America?

A

Campylobacter

45
Q

Does campylobacter have a high or low ID50?

A

High

46
Q

Is campylobacter heat sensitive or heat stable?

A

Sensitive

47
Q

What are the symptoms of campylobacter infection and when do they normally occur?

A
  • 2-5 days
  • Diarrhea with blood and pus
  • Abdominal pain
48
Q

What are the sources of campylobacter?

A
  • Poultry

- Contaminated meat, water, and unpasteurized milk

49
Q

What is the treatment for campylobacter?

A

Fluoroquinolones and macrolides

50
Q

What causes vibrio?

A

Cholera

51
Q

Is vibrio gram negative or positive?

A

Negative

52
Q

What does cholera lead to?

A

Rapid dehydration

53
Q

What are the symptoms of vibrio caused by?

A

The production of an enterotoxin in the GI tract

54
Q

What are the virulence factors of vibrio?

A
  • Flagella
  • Production of mucinase
  • Production of AB toxins
55
Q

What species of shigella causes the most serious infection?

A

Shigella dysenteriae

56
Q

How is shigella transmitted?

A

Oral-fecal

57
Q

Does shigella have a low or high ID50?

A

Low

58
Q

What toxin does shigella produce?

A

Shiga toxin

59
Q

What does shiga toxin damage?

A

Epithelial and kidney cells

60
Q

What is the treatment for shigella?

A
  • Rehydration

- Severe cases require antibiotics

61
Q

What is the most common cause of hospital-acquired diarrhea?

A

Clostridium difficile

62
Q

Does clostridium difficile require broad or narrow spectrum antibiotics and why?

A

Broad because it is resistant to a lot of antibiotics because it can form spores

63
Q

What toxins does clostridium difficile produce?

A

TcdA and TcdB

64
Q

What is the treatment for clostridium difficile?

A
  • Antibiotics for serious infections

- Fecal transplant

65
Q

Why is staph aureus a good pathogen for causing food poisoning?

A

Heat stable and resistant to stomach/small intestine enzymes

66
Q

What is the cause of listeriosis?

A

Listeria monocytogenes

67
Q

What is the gram status and morphology of listeria monocytogenes?

A

Gram positive coccobacillus

68
Q

Where is listeria found?

A
  • Uncooked and unpasteurized food

- Soft cheeses

69
Q

Listeria monocytogenes can still multiply at ____ C

A

4

70
Q

Which groups have an enhanced risk of listeriosis?

A
  • Pregnant women

- Immunocompromised individuals

71
Q

What is the virulence factor of listeria?

A

Can polymerize host cell actin filaments to produce an actin tail that pushes the bacterium into a pseudopod which is endocytized by the host cell

72
Q

How is rotavirus transmitted?

A

Oral-fecal

73
Q

What are the symptoms of rotavirus?

A

Vomiting, diarrhea, and fever

74
Q

What is the treatment for rotavirus?

A

Fluid and salt replacement

75
Q

What can norovirus cause?

A

Gastroenteritis

76
Q

How is norovirus diagnosed?

A
  • Electron microscopy

- RT-PCR

MBIO 3010 (17 decks)

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