Brainscape's Knowledge GenomeTM

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


See full index

Fpathogens > 10 - E.coli > Flashcards

10 - E.coli Flashcards

1
Q

Is North America strongly affected by mortality from diarrhea in children under 5?

A

No

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

E.coli is a gram ______, motile, nonsporulating, rod-shaped, and a facultative anaerobe

A

negative

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

Does E.coli produce spores?

A

No

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

T OR F: E.coli is part of the normal microbial population of the intestinal track of humans, and other warm blooded animals?

A

T

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

T OR F: Most strains of E.coli are pathogenic

A

F

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

E. coli can be categorized into different _________ based on their ability to produce toxins, ability to adhere to epithelial cells, and ability to invade epithelial cells (the pathogenic traits have mostly been acquired through horizontal gene transfer)

A

pathotypes

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

AIEC =

A

Adherent invasive E.coli

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

ETEC =

A

Enterotoxigenic E.coli

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

EAEC =

A

Enteroaggregative E.coli

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

STEC =

A

Shiga toxin producing E.coli

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

EIEC/Shigella =

A

Enteroinvasive E.coli

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

DAEC =

A

Diffusely adherent E.coli

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

EPEC =

A

Enteropathogenic E.coli

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

UPEC =

A

Uropathogenic E.coli

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

E. coli can also be differentiated into serotypes based on three major surface antigens: _ (LPS), __ (flagella), and __(capsule)

A

O
H
K

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

The O antigen defines the ________ of a strain, and the H antigen identifies the _________

A

serogroup

serotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Several serogroups fall into multiple __________

A

pathotypes

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

E. coli strains can be grouped into 5 main phylogenetic groups:

A 
A
B1
B2
D
E

*EIEC/Shigella also forms additional phylogroups (black)

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

T OR F: Pathotypes do not always group together in the same phylogroup.

A

t

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

Name the main 4 parts of the small intestine:

A
  • villi
  • crypt
  • enterocyte
  • microvilli
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

The E.coli genome is very _____________

A

plastic

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

There are about _______ genes in the E.coli core genome, and ___________ genes in its pan-genome

A

1,700

16,400

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

Several _________, ____________, and ___________ regularly moving in and out of bacterial genomes

A

prophages
genomic islands
plasmids

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

Most virulence factors (toxins, and colonization factors) of E. coli are derived from _________________________

A

mobile genetic elements

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

The phenotype (and disease caused) by each phenotype is determined by which virulence factors they have picked up via _____________________

A

horizontal gene transfer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the genes that are considered virulence factors in humans:

A

LEE or Shiga toxins

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

Give me some characteristics of EPEC:

A
  • has the ability to form distinctive lesions on the surfaces of intestinal epithelial cells
  • carries LEE genes (the locus of enterocyte effacement)
  • mainly affects children less than 1 year old in developing countries
  • only transmitted via the fecal-oral route, humans are the only identified carrier
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What can you do to prevent transmission of EPEC?

A
  • proper hygiene methods

- have clean fresh water supplies

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

EPEC does not generally have ________________

A

enterotoxins

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

In EPEC the effacement of microvilli may lead to a decrease in absorptive surfaces thereby __________________________

A

contributing to diarrhea by increasing water in the small intestine

*Tight junctions may also be disrupted, this could lead to increased intestinal permeability

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

STEC is defined by the presence of Shiga toxin 1 & 2 which is acquired by _______________

A

bacteriophage infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

STEC causes what:

A

mild to bloody diarrhea and haemolytic uremic syndrome (HUS)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

HUS is caused by what:

A

The destruction of red blood cells. The damaged red blood cells clog the filtering system in the kidneys, which can lead to life-threatening kidney failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Does STEC have the LEE genes?

A

Yes and STEC can also form lesions on the microvilli like EPEC

35
Q

____________ is the most common serotype of STEC

A

O157:H7

36
Q

What is the transmission route for STEC:

A

fecal-oral route

37
Q

______________________ are responsible for sporadic and outbreak related illnesses of STEC

A

Contaminated food and water

38
Q

Stx toxins are carried on a __________ phage which may become ___________ during bacterial stress, for this reason __________ are not recommended

A

lysogenic
lytic
antibiotics

39
Q

EIEC and Shigella are ______________________ pathogens

A

facultative intracellular

40
Q

EIEC / Shigella are ______________ that divide in the intracellular milieu of intestinal cells

A

invasive

41
Q

T OR F: EIEC / Shigella destabilize the epithelial tight junctions, and induce epithelial cell death

A

T

42
Q

Generally, EIEC and Shigella have the same virulence strategies, though ___________ has increased virulence

A

Shigella

43
Q

Explain the multistep process infection by EIEC/Shigella

A

cells penetrate the epithelial barrier, induce macrophage cell death, invade intestinal epithelial cells, engagement in intra- and intercellular movement, and degrade epithelial integrity

44
Q

Symptoms of EIEC/Shigella include:

A
  • mild watery diarrhea
  • fatigue
  • malaise
  • fever
  • anorexia
45
Q

What happens later in the disease of EIEC/Shigella

A
  • abdominal cramps
  • blood or mucus in diarrhea and dehydration

*usually self-limiting and more serious in the developing world

46
Q

Since Shigella also carries the Stx toxins, _____ can also result

A

HUS

47
Q

What is one difference between STEC and EIEC/Shigella:

A

in the case of EIEC/Shigella antibiotics seem to protect against HUS unlike with STEC

48
Q

______________may be the most common bacterial pathogen identified in patients with diarrhea

A

EAEC

49
Q

________is a causative agent for traveler’s diarrhea

A

EAEC

50
Q

T OR F: EAEC is often transmitted through food and water contaminated with fecal material, such as salads, deserts, salsa – food workers can also be carriers and must practice hygienic measures to keep infection from spreading

A

T

51
Q

What is the 3-part infection model for EAEC infection?

A

1- cells adhere to intestinal mucosa
2- cells produce enterotoxins and cytotoxins
3 - the mucosa becomes inflamed due to toxins and the immune system (diarrhea)

52
Q

The identifying factor of EAEC is that the combination of virulence factors required for the three steps above are all encoded on the _________ plasmid

A

pAA virulence

53
Q

ETEC is also a major cause of _________

A

traveler’s diarrhea

54
Q

ETEC can produce either or both _________ or _______ enterotoxin and produces several colonization factors for adherence to the intestinal epithelium

A

heat-liable

heat-stable

55
Q

No ________________ are in the core-genome of ETEC

A

virulence factors

56
Q

Acquisition of _____________ toxins and __________ factors may be the driving force behind ETEC pathogenesis

A

plasmid-borne

virulence

57
Q

ETEC is the only E. coli to have a ___________, therefore, is a defining characteristic

A

heat-stable toxin

58
Q

How does the heat-stable toxin produced by ETEC acts:

A

it acts by inducing chlorine and fluid secretion into the lumen, thus diarrhea

59
Q

ETEC also affects the ______ industry

A

swine

60
Q

What are the symptoms associated with ETEC?

A
  • mild to severe (non-bloody) diarrhea which rapidly leads to dehydration
  • headaches
  • fever
  • abdominal cramping
  • nausea/vomiting
61
Q

Are antibiotics recommended for ETEC?

A

Antibiotic treatment is not generally recommended, since it will clear up on its own, and antibiotic use must be weighed against the possibility of antimicrobial resistance

62
Q

T OR F: DAEC attach to epithelial cells, but do not follow the classical patterns of adherence, such as attachment and effacement of microvilli

A

T

63
Q

What is special about DAEC?

A

its diffuse pattern of adherence to epithelial cells (adherence occurs over the entire surface of the epithelial cell

64
Q

T or F: Adults can become asymptomatic carriers, but it has been speculated that carrying DAEC leads to chronic inflammatory intestinal disease

A

T

65
Q

What happens when DAEC binds to epithelial cells:

A

it induces actin rearrangement and destroys microvilli, tight-junctions become leaky

66
Q

What is the defining virulence factor of DAEC:

A

the Afa/Dr family of adhesins which allow for the diffuse binding to epithelial cells

67
Q

What is the only treatment for DAEC:

A

oral rehydration

68
Q

______________ has been implicated as a causative agent of Crohn’s Disease, which is a cause of inflammatory bowel disease (IBD)

A

AIEC

69
Q

____ are most related to UPEC

A

AIEC

70
Q

___% of patients with Crohn’s disease carry AIEC

A

30

71
Q

EPEC and LEE-positive STEC are ________________ pathogens that attach to the intestinal epithelium and efface microvilli, forming characteristic A/E lesions.

A

extracellular

72
Q

ETEC uses _______________- for attachment to host intestinal cells

A

colonization factors (CFs)

73
Q

________ forms biofilms on the intestinal mucosa, and bacteria adhere to each other as well as to the cell surface to form an aggregative adherence pattern (AA) known as “stacked brick.”

A

EAEC

74
Q

_______ is dispersed over the surfaces of intestinal cells, resulting in a diffuse adherence (DA) pattern.

A

DAEC

75
Q

_______ colonizes the intestinal mucosae of patients with Crohn’s disease and is capable of invading epithelial cells as well as replicating within macrophages.

A

AIEC

76
Q

EIEC/Shigella are __________________ that penetrate the intestinal epithelium through M cells to gain access to the submucosa. EIEC/Shigella escape submucosal macrophages by induction of macrophage cell death followed by basolateral invasion of colonocytes and lateral spread.

A

intracellular pathogens

77
Q

Acquisition of genes is generally from mobile elements such as _____________, ___________, and __________

A

transposons
prophages
plasmids

78
Q

ETEC isolates carry enterotoxins __ and ___ solely or together on plasmids, as well as colonization factors (CFs).

A

LT

ST

79
Q

DAEC isolates have fimbriae that enhance adherence, called the ______

A

Afa/Dr

80
Q

EAEC virulence factors are found the __________

A

pAA plasmid.

81
Q

EIEC/Shigella gained the ability to invade cells mainly through the _______ plasmid and acquired additional virulence traits in the form of ______

A

pINV

PAIs

82
Q

nes involved in the pathogenesis of ______ are unclear

A

AIEC

83
Q

Important virulence factors include genes that encode the ability to:

A
  • Adhere to epithelial cells
  • Produce toxins
  • Invade epithelial cells
84
Q

What are the most common E.coli pathotypes in food (4):

A

STEC
ETEC
EAEC
EIEC

Fpathogens (23 decks)

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