Lower Alimentary Tract Infections

Question 1

What type of transmission causes most GI infections?

Answer 1

Fecal-oral

Question 2

How to prevent the chain of transmission?

Answer 2

proper disposal and treatment of sewage
disinfection of drinking water
proper food preparation and handling

Question 3

what is the most dominant flora in the intestine?

Answer 3

Gram-negatives, both anaerobes, and aerobes

Question 4

two types of diseases of the GI tract?

Answer 4

infection and intoxication

Question 5

what are the differences/similarities between infection and intoxication?

Answer 5

infection: pathogen multiplies in mucosa/ passes through to other systemic organs; characterized by fever, the release of endotoxin (LPS)
intoxication: ingestion of toxin; sudden onset/no fever or systemic symptoms

BOTH: diarrhea, major cause of infant mortality (Dehydration)

Question 6

what are the main pathogenic mechanisms of LAT pathogens?

Answer 6

attachment, cell invasion, loss of microvilli, exotoxin production

Question 7

what are two actions of exotoxin on the gut?

Answer 7

1. increase the secretion of water and electrolytes

2. inhibit protein synthesis and cause cell death

Question 8

GI pathogens and gram-negative have both ___ and ___.

Answer 8

endotoxin; exotoxin

Question 9

Differences between Dysentery and Gastroenteritis

Answer 9

Dysentery often has pus, whereas gastroenteritis does not.

Question 10

How do you call the exotoxins produced by S. aureus?

Answer 10

enterotoxin

Question 11

What are the characteristics of enterotoxin?

Answer 11

heat stable and resistant to enzymatic destruction

Question 12

What does enterotoxin do?

Answer 12

trigger vomiting reflex

Question 13

What two main symptoms do Bacillus cereus cause?

Answer 13

Diarrhea and vomiting

Question 14

Bacillus cereus causes infection or intoxication?

Answer 14

BOTH!

Question 15

What are the two types of Salmonella infection?

Answer 15

Gastroenteritis and Typhoid fever (aka. enteric fever)

Question 16

What are the differences between Salmonella Gastroenteritis and Typhoid fever in terms of the transmission method and treatment?

Answer 16

Salmonella Gastroenteritis: zoonotic; not usually treated with antibiotics
Typhoid fever: human to human; always antibiotics

Question 17

Is Shigellosis an infection, or intoxication?

Answer 17

infection

Question 18

What’s the transmission method for Shigellosis?

Answer 18

person to person, no animal reservoir

Question 19

What is the main virulence factor for Shigellosis

Answer 19

Shiga toxin

Question 20

What is the leading cause of foodborne bacterial illness in Canada?

Answer 20

Campylobacter Gastroenteritis

Question 21

What is EHEC?

Answer 21

causes “Hamburger Disease”

Pathogenic strains that have special fimbriae for attachment to intestinal cells and produce toxins

Question 22

What is the best-known serotype for EHEC?

Answer 22

0157:H7

Question 23

What complication does EHEC usually cause?

Answer 23

HUS (hemolytic uremic syndrome)

Question 24

Is there a vaccine for EHEC?

Answer 24

NO

Question 25

What is pigbel?

Answer 25

gangrene of intestines ``` // Gangrene refers to the death of body tissue due to either a lack of blood flow or a serious bacterial infection ```

Question 26

Clostridium Gastroenteritis can be serious for what kind of people?

Answer 26

Who lack trypsin or eat a diet rich in trypsin inhibitors --> result in Pigbel

Question 27

What's the name of the bacteria that cause a GI global pandemic?

Answer 27

Vibrio cholerae

Question 28

What is the treatment for Vibrio cholerae?

Answer 28

rehydration glucose + electrolytes

Question 29

Viral gastroenteritis are mainly caused by _______ or ______.

Answer 29

rotavirus or norovirus

Question 30

Describe the incidence of Rotavirus Gastroenteritis

Answer 30

the same incidence in developed and underdeveloped nations.

Question 31

Rotavirus is the most common cause of viral gastroenteritis in which population?

Answer 31

children

Question 32

Norovirus is also known as ______ virus.

Answer 32

cruise ship virus

Question 33

What are the early symptoms of Norovirus

Answer 33

no prodrome.

Question 34

What are the two parasitic diseases of the GI?

Answer 34

protozoan diseases | Helminthic diseases

Question 35

What is the difference between protozoan diseases | and helminthic diseases?

Answer 35

protozoan diseases cause diarrhea | Helminthic diseases cause no diarrhea

Question 36

What type of hepatitis virus causes most cases of acute hepatitis?

Answer 36

Hepatitis A

Question 37

What type of hepatitis virus is the major transmission sexual?

Answer 37

Hepatitis B

Question 38

What type of hepatitis virus is transmitted bloodborne and is a major cause of liver cirrhosis

Answer 38

Hepatitis C

Question 39

What type of hepatitis virus is an Incomplete virus, hangs around with HBV?

Answer 39

Hepatitis D

Question 40

What type of hepatitis virus is dangerous for pregnant women in underdeveloped countries?

Answer 40

Hepatitis E