ch 20

large intestine

part of the GI tract is most heavily colonized with various microbes

Endogenous E. coli is an important microbe in the GI tract. What does it do?

produces vitamin K

Bloody stools and fever are more commonly associated with ____ causes of diarrhea.

bacterial

Vomiting is more commonly associated with ____ causes of diarrhea.

viral

Many causes of acute diarrhea spread by food, beverage, and fecal-oral routes. Which also spreads by direct contact?

Shigella

HUS stands for

hemolytic uremic syndrome

HUS

• can impact the kidneys and leave lasting damage

• appears in about 10% of STEC infections

• can have neurologic impacts that may be permanent

What are the best ways to prevent acute diarrhea from bacterial causes?

• proper food handling

• hand hygiene

• water treatment

Which two come from livestock, particularly cattle, but can contaminate produce as well?

• Shiga-toxin E. coli

• Non-shiga toxin E. coli

subspecies of Salmonella typhi

typhi

gastroenteritis

inflammation of the stomach and intestines

What should not always be associated with gastroenteritis?

fever

What is the best course of action for treating diarrhea?

rehydration

Why aren’t antibiotics prescribed more often for bacterial infections that cause diarrhea?

most cases of diarrhea are self limiting and will resolve on their own

dysentery

blood in the stool

emesis

vomiting

acute diarrhea

3+ loose stools per day for a few days

chronic diarrhea

3+ loose stools per day for 14+ days

Why does an individual lose so much fluid when infected with cholera?

cholera toxin causes electrolyte shedding and water loss

What is the most common cause of foodborne illness in the U.S.?

Norovirus

How many viral particles are necessary for an infectious dose of norovirus?

10-100

Which cause of chronic diarrhea is bacterial?

Enteroaggregative E. coli

Which causes of chronic diarrhea are protozoan?

• Cyclospora

• Giardia

• Entamoeba

Which causes of chronic diarrhea are most commonly seen outside the US?

• Giardia

• Entamoeba

What does not cause food poisoning?

Clostridiodes difficile exotoxin

Why is food poisoning considered to be intoxication instead of an infection?

because the disease comes from the toxins, not the presence of the bacteria

BRAT diet

• primarily bland foods

• the foods are meant to be easily digestible and solidify stool

BRAT diet stands for

bananas, rice, applesauce, toast

Why is proper food storage important?

to keep temperatures outside the range of optimal microbial growth

Which of the following scenarios is more likely to involve Clostridium perfringens food poisoning?

Green beans that were cooked and left to cool on the stove. Green beans that were cooked and left to cool on the stove.

heptatitis

inflammation of the liver

Why does hepatitis cause jaundice?

buildup of bilirubin normally processed by the liver

cirrhosis

scarring of the liver

Which infection often goes unnoticed until aggravated by other conditions?

stomach ulcers

A common sign of helminth infection is:

eosinophilia

Why will a patient not show increased eosinophils levels for a tapeworm infection?

they avoid systemic responses by staying in the lumen of the intestine

cystcercosis

consumption of larva leading to migratory symptoms

Neurocysticercosis can cause:

vision problems

Cysticercosis in muscles can cause:

lumps under the skin

Put the steps of pork tapeworm infection in order

1. eggs hatch in pigs

2. larvae move to organs and encyst

3. humans eat undercooked pork

4. larvae hatch in intestines and adult worm attaches