L10 - GI infections 2: Viral Gastroenteritis

Question 1

Which toxin produced by E-Coli can mimic cholera?

Answer 1

LT toxin.
Heat labile enterotoxin.
LT-1 can mimic cholera.

Question 2

Describe how salmonella results in diarrhoea?

Answer 2

• Uptake by M cells
• bacteria migrate through lamina propia (lies beneath epithelium) of ileocecal region.
• bacteria multiply.
• stimulates inflammatory response.
• causes prostaglandin release.
• cAMP activated.
• fluid secretion
• diarrhoea

Question 3

Describe damage caused by campylobacter?

Answer 3

Inflamed bleeding mucosal surfaces in the jejunum, ileum and colon.

Question 4

What is used to relieve severe campylobacter diarrhoea?

Answer 4

Erythromycin.
Macrolide antibiotics
- inhibits bacterial protein synthesis by binding reversibly to 50S ribosomal subunits of sensitive micro-organisms.

Question 5

Describe Shigellosis?

Answer 5

Infects mucosa of large intestine.
Inflammation, presence of blood and pus in stool.

Shigella diarrhoea usually watery at first but can later contain mucus and blood.

Shigellae attach, invade mucosal epithelium of the distal ileum and colon causing inflammation and ulceration.

Question 6

Describe Yersinia entercolitica?

Answer 6

Vibrio parahaemolyticus is gram negative bacterium found in raw seafood.
- invades terminal ileum, necrosis in peyer’s patches, associated inflammation of the mesenteric lymph nodes

Question 7

Describe two common symptoms of bacterial gastroenteritis?

Answer 7

1. Water Diarrhoea

2. Dysentery: mucosal invasion and damage, diarrhoea with blood

Question 8

Describe C.Diff enterotoxins

Answer 8

Toxin A - entertoxin

Toxin B

• cytotoxic
• causes bloody diarrhoea

Question 9

Severity of C.Diff can be seen in what factors?

Answer 9

• increase in temp
• increase in WBC
• increase in serum creatinine
• increase in serum lactate

Question 10

Antibiotic therapy may be given in gastroenteritis if:

Answer 10

• dysenteric symptoms
• severely dehydrated
• severe systemic symptoms
• immunosuppressed
• cholera likley

Question 11

Investigations

Answer 11

• urea, electrolyte, stool, microscopy, stool

Question 12

Ulcerative colitis

Answer 12

• Chronically relapsing inflammatory disease of the large intestine, idiopathic
• intense hyperaemia of intact mucosa
• hyperaemia - excess of BV supplying
• inflammation of mucosa, presence of many plasma cells at base of mucosa is indicative

Question 13

Vascular disorders

Answer 13

Vascular occlusion

Vascular stenosis: narrowing

Question 14

Necrotising entercolitis

Answer 14

Abdominal distention.
Serious in newborns.
Bloody stools.

Question 15

Diverticulitis

Answer 15

Herniated mucosa

Question 16

Intussusception

Answer 16

Invagination of one segment of bowel into another.

Resulting in intestinal obstruction.

Question 17

Management of viral entercolitis

Answer 17

Side room and contact precautions

Rehydrate

Inform public health if food associated