Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Hugh's MD1 Abdominal > Infective Gastro > Flashcards

Infective Gastro Flashcards

(63 cards)

Start Studying
1
Q

What are the common aetiological causes of travellers diarrhoea?

A

ETEC, other bac. viruses and protozoa

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

What diagnotic techniques are commonly used to identify bacteria?

A

Culture

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

What are the aetiological agents responsible for dysentery?

A

Shigella, EIEC and protozoa (Entamoeba histolytica)

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

What the most common parasitic causes of diarrhoea in the developed world?

A

Giardia and crytosporidium

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

What is dysentery characterised by?

A

Blood, mucus and pus in the stool - more than just severe diarrhoea!

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

What is the problem with anti-motility agents?

A

They stop peristalsis which is a defense mechanism for the removal of pathogens.

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

What type of pathogen is the most common cause of diarrhoea in the developing world?

A

Bacteria

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

What diagnostic techniques are most commonly used to identify viruses?

A

Nucleic acid identification

Antigen detection

(Microscopy)

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

Why is oral rehydration preferable to intravenous in children?

A

Doesn’t require a highly skilled paediatrician to insert the needle

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

How do some mothers in developing countries contribute to gastro malnutrition?

A

They stop breast feeding as they think the milk might be the cause of the problem.

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

What type of *E. coli *produce shiga toxin?

A

EHEC (enterohaemorrhagic E. coli)

EAEC if it acquires a plasmid for it

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

What does EPEC stand for? What symptoms does it cause?

A

Enteropathogenic E. coli

Non-specific gastro in children in LDCs

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

What are the two ways diarrhoea kills people?

A

Immediate phase due to water and electrolyte imbalance

Delayed: mainly due to malnutrition due to enterocyte damage

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

What is the limitation with culturing faeces?

A

Generally only pathogens that are easy to find are looked for…

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

What happens if more than 4-5L of fluid enters the colon?

A

The excess is excreted as diarrhoea

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

What level of invasiveness is EPEC in terms of its diarrhoea causing ability?

A

Adhesive with brush border damage (destroy microvilli)

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

What is the function of Tir protein in EPEC infection?

A

Tir is secreted by the type III secretion sytem into enterocytes cytoplasm where is finds its way to the lumen membrane and acts as a receptor for intimin

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

How does diarrhoea contribute to malnutrition?

A

Increased nutrient/energy loss

Reduced energy intake (malabsorption, withholding of food)

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

Of the 5 variants of pathogenic E. coli that cause GI symptoms, which cause severe disease?

A

EHEC - bloody diarrhoea

EIEC - dysentery

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

Shiga toxin is associated with which clinical conditions?

A

Haemorrhagic colitis

Haemolytic-uremic syndrome

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

What are three classes of anti-diarrhoeal drugs?

A

Anti-motility agents

Anti-secretory agents

Binding agents

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

Why don’t animals infected with EHEC get as sick?

A

They have shiga toxin receptors that absorb the toxin

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

How does Salmonella manage to systemically invade?

A

Remains in macrophages

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

Of the 5 variants of pathogenic *E. coli *that cause GI symptoms which cause milder disease?

A

EPEC

EAEC

ETEC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
What diagnostic techniques are commonly used to identify parasites?
Microscopy Antigen detection (detection of nucleic acids)
16
What is pathotyping? For what pathogen/s is it important?
Determination of virulence factors ## Footnote * E. coli* * Yersinia*
18
What causes enteric fever?
*Salmonella* Typhi and *S.* Paratyphi
19
What does EAEC stand for? What symptoms does it cause?
Enteroaggregative *E. coli* Watery diarrhoea in childrens in LCDs
20
What is the function of Intimin protein in EPEC infection?
Intimin is an attachment protein EPEC uses to mediate intimate adhesion with enterocytes. It binds to Tir, a receptor also produced by EPEC
22
T/F Shigella has no animal reservoir
True
22
For what pathogen is serotyping important?
*Salmonella*
22
What are some strategies against traveller's diarrhoea?
Reduce exposure to infectious agent Immunisation (Antimicrobials)
23
T/F Using antibiotics for cholera infection has no effect
False, it shortens the illness and infectious period
25
Where is the most fluid absorbed?
Duodenum and jejunum.
26
What species of *Shigella* causes the most severe dysentery?
*S. dysenteriae*
28
What does ETEC stand for? What symptoms does it cause?
Enterotoxigenic *E. coli* Causes watery diarrhoea (in young children and travellers in LDCs)
29
Apart from *cholerae* what causes Cholera-like diarrhoea?
ETEC - discovered in soilders
31
What is haemorrhagic colitis? What causes it?
Blood in the stool (not pus) EHEC
32
What percentage of under 5 deaths are due to malnutrition?
33%
33
How do you treat diarrhoea?
Replace fluids - most important Reduce fluid loss - less important
34
How much fluid do we secrete from the GIT each day?
100mL
35
*Entaemoba histolytica *containing what thing indicates it's the cause of dysentery?
RBCs
37
Which diarrhoea causing bacteria invade the submucosa?
*Salmonella, Campylobacter*
38
What does seeing trophozoites of *Giardia lamblia *in diarrhoea stool samples indicate?
That *Giardia *isn't causing the diarrhoea because only the cyst stage is release in stool in normal *Giardia *infection. The presence of trophozoites indicates that there is another cause of diarrhoea that is forcing immature *Giardia *down the GIT prematurely.
39
What is the principle of binding agents?
Attach a toxin's receptors to sand so that the toxin is absorbed in the gut
41
T/F Bacteria is the major cause of diarrhoea in the developed world.
False, viruses are!
42
What does EIEC stand for? What symptoms does it cause?
Enteroinvasive *E. coli* Dysentery, any age, mainly LDCs
43
*Clostridium difficile *is the major cause of what diarrhoeal syndrome?
Antiboitic-associated colitis
44
T/F *V. Cholerae* and *Shigellae* are both found in the environment
False, only *Cholerae* is found in the environment
46
Which of the 5 *E. coli *utilise type III secretion systems?
EPEC and EHEC
47
Has does glucose increase fluid uptake?
It is co-transported into villus cells with Na creating an osmotic gradient for water to travel down
48
T/F Type III secretion systems are found in pathogens only
True
50
What is the pattern of diarrhoea when there is malaborption in the colon?
Frequent events of low volume
52
The causes of foodborne diarrhoea include...
*Staph, Salmonella, Clostridium, Bacillus, Vibrio, Listeria*, viruses (eg Norovirus), ciguatoxin
53
What are 4 virulence factors?
Adhesions factors Endotoxins Avoidance of immune responses Invasive ability
54
When should antiboitics be used in the treatment of diarrhoea?
Cholera Systemic spread of infection eg typhoid fever Immunocompromised patients Severe shigella infections Protozoal infections (even if carrier only) Pseudomembranous colitis if severe
55
What is the most important ingredient in rehydration salts?
Glucose
57
How much fluid does the colon usually absorb? What is the maximum it can absorb?
1.4L and 4-5L
59
Why is the name non-specific gastroenteritis inaccurate?
Because it refers to symptoms of diarrhoea and vomiting only and does not include actual inflammation in the GIT
60
Which virus' virion is smaller: Rotavirus, Norovirus or enteric adenovirus?
Norovirus at 30nm The others are 70nm
61
T/F bacteria are present in amoebic dysentery
False, the amoebae eat the bacteria
62
Clostridium is a ...
Gram positive rod Forms endospores Strictly anaerobic
63
How many species of dysentery causing *Shigella *are there?
4

Hugh's MD1 Abdominal (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions