Bacterial gastroenteritis

Bacterial gastroenteritis

Updated: 01/26/2024

© Jun Wang, MD, PhD

 

General features

  • Infection of bacteria
  • Produce endotoxin and exotoxin
  • Secretory
    • Bacillus cereus: rice
    • Enterotoxigenic E. coli: recent travel
    • Clostridium perfringens: undercooked meat, raw legumes
    • Vibrio cholerae: Sea food, water
    • Staphylococcus aureus: Inadequately refrigerated food
  • Invasive
    • Yersinia: mile, pork
    • Typhi or paratyphi salmonella: recent travel
  • Inflammatory

Endotoxin

  • Components of the cell wall of G-negative bacteria
  • Released by death of bacterial, antibiotics, or antibodies
  • Cause fever: Release of interleukin-1
  • Cause shock: TNF associated hypotension and endothelial damage
  • Release of nitric oxide: Vasodilation, bacterial crossing blood-brain barrier

Extoxin

  • Secreted by both G+ and G- bacteria
  • A/B components
    • B: binds to receptor
    • A: active (toxic)
  • ·Cytolysins
    • Lyse cells by damaging membrane
  • Toxoids
    • Chemical modification
    • Used in vaccines
  • Inhibit protein synthesis
  • Activate immune system: non-specific polyclonal T-cell activation, cytokine releases, etc
  • Promote secretion: activate cAMP pathways, etc
  • Cytolysis: membrane damage, tissue necrosis

Diagnostic approaches

  • CBC
  • Stool tests
  • Stool microbiology tests

o   Culture

o   Molecular tests: More sensitive and rapid than culture

  • Stool microbiology tests recommended when
    • Severe illness: hypovolemia, severe diarrhea and severe abdominal pain
    • Signs of inflammatory diarrhea: fever, stools with blood with or without mucus
    • High-risk host features: old age ≥70 years, severe comorbidities such as heart diseases, immunocompromising condition, inflammatory bowel disease, pregnancy
    • Symptoms persisting for more than one week
    • Public health concerns

Management

  • Fluid and electrolytes replacement
  • Symptom relief
  • Antibiotics: Not needed for self-limited cases
  • Antimotility agents: Usually not indicated

 

 

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