- Microbiology & Etiology
- Gram-negative rod, oxidase (+).
- Curved, comma or S-shaped (seagull wing appearance).
- Thermophilic: Grows best at 42°C (Campy-fire burns hot).
- Motile (polar flagella).
- Transmission
- Fecal-oral route.
- Major reservoir: Intestinal tract of animals (esp. poultry).
- Risk factors: Ingestion of undercooked poultry, unpasteurized milk, contact with infected animals (puppies/kittens).
- Pathophysiology
- Organism invades the mucosa of the colon and destroys epithelial cells.
- Produces cytolethal distending toxin → cell cycle arrest and DNA damage.
- Inflammation leads to bloody, inflammatory diarrhea.
- Clinical Features
- Incubation: 1–7 days.
- Prodrome: Fever, headache, myalgia.
- GI: Acute enteritis with crampy abdominal pain (often RLQ → mimics appendicitis or pseudoappendicitis) and diarrhea (watery → bloody). t
- One of the most common causes of bacterial gastroenteritis in the US.
- Diagnostics
- Stool Culture: Gold standard.
- Requires selective media (Skirrow agar or Campy-BAP) containing antibiotics (vancomycin, polymyxin B, trimethoprim).
- Incubated at 42°C under microaerophilic conditions.
- Stool leukocyte/lactoferrin (+).
- Complications
- Guillain-Barré Syndrome (GBS):
- Ascending paralysis/weakness.
- Mechanism: Molecular mimicry. Antibodies against C. jejuni lipooligosaccharides cross-react with gangliosides (e.g., GM1) in peripheral nerve myelin/axons.
- Reactive Arthritis (Reiter syndrome):
- Triad: Urethritis, Uveitis, Arthritis (“Can’t see, can’t pee, can’t climb a tree”).
- Assoc. with HLA-B27.
- Treatment
- Supportive Care: Fluid and electrolyte replacement (mainstay).
- Antibiotics (reserved for severe/prolonged cases):
- First-line: Azithromycin (macrolides).
- Alternative: Fluoroquinolones (though resistance is increasing).