Micro 7 - Diarrhea

Question 1

What are the four types of Escherichia coli?

Answer 1

1. Enterotoxigenic E. coli (ETEC) 2. Enterohemorrhagic E. coli (EHEC) 3. Enteropathogenic E. coli (EPEC) 4. Enteroinvasive E. coli (EIEC)

Question 2

Describe Enterotoxigenic E. coli (ETEC).

Answer 2

1. Water diarrhea due to heat-liable and heat stable enterotoxins. 2. Does not infect the intestinal wall 3. Most common type of traveler’s diarrhea.

Question 3

Describe enterohemorrhagic E. coli (EHEC).

Answer 3

1. Bloody diarrhea and severe illness from infected meat. 2. Most common is 0157:H7 3. Produces shiga-like toxins. 4. Can lead to hemolytic uremic syndrome (HUS): anemia, thrombocytopenia, acute renal failure. Treatment: supportive.

Question 4

Describe Enteropathogenic E. coli (EPEC).

Answer 4

1. Watery diarrhea, but not toxin produced. 2. Common in children.

Question 5

Describe Enteroinvasive E. coli.

Answer 5

1. Bloody diarrhea and fever due to intestinal wall invasion. 2. Closely related to Shigella.

Question 6

What is the treatment for Enteroinvasive E. coli (EIEC)?

Answer 6

Fluoroquinolones, TMP-SMX, azithromycin.

Question 7

Describe clinical features of Shigella.

Answer 7

1. Causes watery diarrhea that turns to bloody diarrhea by invading the intestinal mucosa, causing inflammation and necrosis. Causes mucus and fever. 2. Produces Shiga toxins as well. 3. Lasts for 1-2 weeks. 4. It is a non-lactose fermenter.

Question 8

How is Shigella spread?

Answer 8

1. Person to person contact. 2. Contaminated food and water.

Question 9

How does Shigella differ from Salmonella in terms of their anatomical structure?

Answer 9

Shigella does not have flagella. Salmonella does.

Question 10

What is the treatment for Shigella?

Answer 10

Suppurative. In severe cases: Fluoroquinolones = 1st line. TMP-SMX or azithromycin = 2nd line or pediatrics.

Question 11

Which bacteria infections are related to cause Reiter syndrome?

Answer 11

1. Shigella flexneri 2. Salmonella

Question 12

What is the clinical presentation of Salmonella?

Answer 12

1. Bloody diarrhea and fever that begins 1-3 days later. 2. Non-lactose fermenter 3. Picnic setting, egg salad or chicken salad. 4. Turtles, pet stores.

Question 13

How is salmonella diagnosed?

Answer 13

Stool culture.

Question 14

What is the treatment for salmonella?

Answer 14

Healthy adults need only supportive care. In intense cases, fluoroquinolones = 1st line.

Question 15

What is the bacteria that needs to be suspected in osteomyelitis in sickle cell patients?

Answer 15

Salmonella due to having flagella that gives them ability to spread hematogenously.

Question 16

What is classic clinical presentation of Salmonella typhi?

Answer 16

“Rose spots” on the abdomen.

Question 17

Describe campylobacter jejuni.

Answer 17

1. G(-) 2. Z-shaped 3. Oxidase positive 4. Bloody diarrhea, especially in children 5. Grows in at 42C [Campylobacter likes it hot like a camp fire] 6. Self-limited but can last for 1-2 weeks.

Question 18

How is Campylobacter jejuni transmitted?

Answer 18

Fecal-oral; poultry, meat, unpasteurized milk.

Question 19

Which disease is campylobacter jejuni associated with?

Answer 19

Guillain-Barre syndrome.

Question 20

Describe Vibrio cholerae.

Answer 20

1. G(-) 2. Oxidase positive bacilli 3. Watery diarrhea “Rice-water”- Causes profound diarrhea. 4. Flagellum 5. Grows in alkaline media

Question 21

What does the toxin of Vibrio cholerae do?

Answer 21

Permanently activates cAMP.

Question 22

What is the treatment for Vibrio cholerae?

Answer 22

Aggressive oral rehydration.

Question 23

What disease can Yersinia enterocolitica cause that can mimic appendicitis?

Answer 23

Mesenteric adenitis

Question 24

How is Yersinia enterocolitica spread?

Answer 24

From undercooked pork and milk and hosehold pets.

Question 25

Describe Klebsiella pneumoniae.

Answer 25

1. G(-) 2. Lactose fermenting 3. Normal intestinal flora 4. Affects people with weakened immune systems: alcoholics, dibatics, chronic illness.

Question 26

What pathologies does Klebsiella pneumoniae cause?

Answer 26

1. Lobar pneumonia 2. Red currant jelly sputum 3. Necrosis in the lungs 4. Major cause of UTIs

Question 27

Describe Clostridium difficile.

Answer 27

1. Gram (+) 2. Oxidase negative 3. Spore-forming bacilli 4. Produces Toxin A and Toxin B.

Question 28

What does Toxin A of C. difficile cause?

Answer 28

AKA enterotoxin, binds to the brush border of the gut, leads to intestinal fluid secretion and inflammation.

Question 29

What does Toxin B of C. difficile cause?

Answer 29

Kills enterocytes by targeting the cytoskeletal structures of the enterocytes. Causes pseudomembranous colitis.

Question 30

Describe pseudomembranous colitis and primary risk factor.

Answer 30

Necrosis with exudates, fibrin and leukocytes of the colon caused by overgrowth of C. difficile. Primary risk factor is antibiotic use, especially cindamycin and ampicillin.

Question 31

How do we test for Pseudomembranous colitis?

Answer 31

C. diff toxin in the stool.

Question 32

How do we test pseudomembranous colitis?

Answer 32

1. Metronidazole 2. Vancomycin (orally).

Question 33

Why do we use vancomycin orally instead of the usual IV way in pseudomembranous colitis?

Answer 33

Because when taken orally, it is not absorbed systematically; its stays on the gut, hoping to control C. diff. This is why it also will not cause nephrotoxicity as it usually does.

Question 34

What foods are associated with Staph aureus?

Answer 34

Meats, mayonnaise, potato salad, and custard.

Question 35

Why does Staph aureus produce rapid onset of symptoms when ingested?

Answer 35

Preformed toxin.

Question 36

What bacteria is associated with reheated rice?

Answer 36

Bacillus cereus.

Question 37

What bacteria is associated with shellfish?

Answer 37

Vibrio parahaemolyticus and vulnificus.

Question 38

What food is associated with Clostridium botulinum?

Answer 38

Improperly canned foods.

Question 39

What bacteria is associated with clostridium perfringens?

Answer 39

Reheated meat disehes.

Question 40

What bacteria is associated with undercooked contaminated hamburger meat?

Answer 40

E. coli O157:H7

Question 41

Which form of E. coli causes hemolytic-uremic syndrome (HUS)?

Answer 41

E. coli O157:H7

Question 42

Which bacteria is associated with food poisoning as a result of mayonnaise sitting out for too long?

Answer 42

Staph aureus

Question 43

Which bacteria is associated with diarrhea caused by G(-) nonmotile organism that does not ferment lactose?

Answer 43

Shigella

Question 44

Which bacteria is associated with rice-water stools?

Answer 44

Vibrio cholerae Could potentially be Enterotoxigenic E. coli.

Question 45

Which bacteria is associated with diarrhea caused by S-shaped organism?

Answer 45

Campylobacter

Question 46

Which bacteria is associated with diarrhea transmitted from household pets?

Answer 46

Yersinia enterocolitica

Question 47

Which bacteria is associated with food poisoning resulting from reheated rice?

Answer 47

Bacillus cereus

Question 48

Which bacteria is associated with diarrhea caused by G(-) motile organism that does not ferment lactose?

Answer 48

Salmonella.

Question 49

Which bacteria is associated with the most common cause of traveler's diarrhea?

Answer 49

ETEC

Question 50

Which bacteria is associated with diarrhea after a course of antibiotics?

Answer 50

Clostridium difficile

Question 51

Which bacteria is associated with food poisoning due to exotoxin?

Answer 51

S. aureus and Bacillus cereus

Question 52

Which bacteria is associated with osteomyelitis in sickle cell disease?

Answer 52

Salmonella.