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Med 2 - Week 57 > Enteric Infections > Flashcards

Flashcards in Enteric Infections Deck (53)
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1

Define: secretory diarrhea
- what are the features?

- Watery diarrhea w/o fever or with minimal fever.
- Continues despite increasing intake of food and water
- mid abdominal pain

2

Define: Inflammatory diarrhea

- mucoid like diarrhea
- accompanied by fever
- may often be bloody and have WBC in the stool
- lower abdominal and rectal pain

3

Where does secretory diarrhea originate in the GI tract

small bowel

4

What are 5 examples of causative pathogens of secretory diarrhea?

1. Vibrio cholera
2. Rotavirus
3. E. coli (ST or LT)
4. Norovirus
5. Giardia

5

What are 5 examples of causative pathogens of inflammatory diarrhea?

1. Shigella
2. Campylobacter
3. E. coli (EHEC/STEC)
4. Entamoeba histolytica
5. C. difficile

6

What are the two toxins that C. diff produces? Which is more pathogenic?

Toxin A (enterotoxin) and B (cytotoxin)
- Toxin B is more pathogenic

7

What are 2 medication types that increase risk for C. diff?

1. broad spectrum antibiotics

2. PPIs

8

What is the diarrhea like with C. difficile?

watery and foul smelling (like a barn)

9

What is the leukemoid reaction?

phenomenon of an increase in WBC count that mimics leukemia but is due to infection
- common in C. diff

10

What is the treatment approach for C. diff?

1. Stop unnecessary antibiotics
2. Metronidazole (IV or oral) and Vancomycin (oral only)
3. Stool transplant to replenish to replenish microbiota

11

what are 3 virulence factors that pathogenic E. coli have?

1. Fibriae: allow for colonization

2. Adhesions: allow for cell invasion

3. Toxins: both endo and exo

12

Shiga toxin is an example for what kind of toxin?

Exotoxin = secreted

13

What is ETEC and what specific pathogenic adaptations does it have?

Enterotoxigenic E. coli

1. fimbriae for attachment
2. Heat labile (LT) toxin similar to cholera
3. heat stable toxin (ST)

14

What is the clinical syndrome for ETEC diarrhea?

mild water diarrhea and nausea but no vomiting for 1-4 days

15

What is the pathogenesis of ETEC diarrhea?

ingestion of fecally contaminated food/water with 10^8-10 bacteria needed to cause disease

16

What is the treatment for ETEC diarrhea?

Oral rehydration

17

What are EHEC and STEC?

They're the same thing

enterohemorrhagic e. coli and shigatoxin producing e. coli

18

What are the virulence factors specific to EHEC/STEC

The shiga toxin (A/B) toxin
- acts on ribosomes to block protein synthesis leading to cell death
- has preference for enterocytes and endothelial cells in the kidney

19

What is the clinical syndrome of EHEC/STEC?

vomiting, diarrhea (often bloody), and abdominal pain

for children: 5-10 days later can develop lethargy, anemia, oliguria = hemolytic uremic syndrome

20

What are the two forms of salmonella?

non-typhoidal and typhoidal

21

What are the forms of non-typhoidal salmonella? What kind of illness do they cause?

Enteritidis and thyphimurium
- usually not invasive, self resolving disease

22

What are the forms of typhoidal salmonella? What kind of illness do they cause?

Typhi and parathyphi
- cause invasive disease with fever and bacteremia which is fatal if not treated

23

what are the typical reservoirs of non-typhoidal salmonella?

reptiles and chickens

24

What is the clinical picture of non-typhoidal salmonella?

Acute diarrhea with fever and abdominal pain that resolves within 4-7 days

25

What is the reservoir of typhoidal salmonella?

human only

26

What are the clinical symptoms of typhoidal salmonella disease?

Not always diarrhea! Can be constipated
- can lead to ileus and perforation

Long fevers + rash, headache

27

Where can salmonella typhi reside in the body dormant

the gallbladder

28

What is the virulence factor of typhoidal salmonella?

Vi capsular antigen which prevents phagocytosis

29

What is the treatment for typhoidal salmonella?

antibiotics based on local resistance

30

What are 3 adaptations that H. pylori have to increase colonization in the stomach ?

1. urease: converts urea to ammonium to neutralize stomach acid
2. swimming ability: spiral shape + flagella
3. Adhesions to bind to epithelial receptors