Bacterial Infections of the Digestive System

Question 1

What shape is Helicobacter pylori?

Answer 1

vibrio (comma-shaped)
-Gram negative able to survive in acidic environment

Question 2

What diseases does Helicobacter pylori cause?

Answer 2

Gastritis, peptic ulcers, stomach cancer

Question 3

What virulence factors help Helicobacter pylori live in the stomach and cause damage?

Answer 3

Adhesins: attachment to gastric epithelial cells
Flagella: burrowing through stomach lining
Urease: convert urea to ammonium and bicarbonate (both are alkaline and neutralize acid)

Question 4

What type of cancer is associated with Helicobacter pylori?

Answer 4

Stomach cancer

Question 5

What bacterium causes antimicrobial associated diarrhea?

Answer 5

Clostridium difficile
-Gram positive bacilli
-endospore former

Question 6

How does antimicrobial usage cause infection?

Answer 6

Kills off normal flora (bacteria) that keeps C. diff in check, allowing spores to germinate and grow

Question 7

How does toxin A of C-diff. alter the intestine?

Answer 7

breaks junctions between cells of mucosal epithelium in the colon.
Triggers inflammation ->fluid loss

Question 8

How does toxin B of C-diff. alter the intestine?

Answer 8

Kills mucosal epithelium cells
makes lesions that form to make pseudo membrane

Question 9

Clinical features of antibiotic associated diarrhea

Answer 9

Watery diarrhea, fever, appetite loss, nausea, abdominal pain, pseudo membrane colitis

Question 10

Antibiotic associated diarrhea transmission

Answer 10

feces, surfaces contaminated with C. diff, hands of healthcare personnel who touched contaminated surface

Question 11

how does the bacterium’s ability to form endospores outside the body contribute to the spread?

Question 12

Fecal transplant rationale

Answer 12

Restores balance
-introduces new good bacteria into the colon to regulate C. diff

Question 13

Helicobacter pylori transmission?

Answer 13

oral-to-oral or oral-to-fecal route