Pasteurella multocida
Related Subjects:
| Pasteurella Multocida
| Capnocytophaga canimorsus
| Snake Bites
| Dog Bites
| Tetanus
| Pasteurella multocida
| Listeriosis
| Moraxella catarrhalis
| Leptospira interrogans
| Lactobacillus acidophilus
| Helicobacter pylori
| Haemophilus parainfluenzae
| Haemophilus influenzae
⚠️ Pasteurella multocida is resistant to flucloxacillin and erythromycin - so standard skin antibiotics may fail.
📖 About
- Pasteurella multocida → zoonotic bacterium transmitted from animals to humans.
- Most commonly causes infection after dog 🐶 or cat 🐱 bites/scratches.
- Carried in saliva of ~50% of dogs and up to 90% of cats.
🔬 Characteristics
- Gram-negative, pleomorphic, “heme-loving” coccobacilli.
- Fastidious growth, but grows well on blood agar.
🏠 Source
- Normal flora of the oral cavity in cats, dogs, pigs, and other animals.
- Transmission via bites, scratches, or licking broken skin.
⚠️ Pathogenicity
- Soft tissue infection: Rapid-onset cellulitis, erythema, swelling, and pain after animal bite.
- Cat bites: High risk due to deep puncture wounds → can cause abscesses or tenosynovitis.
- Complications: Septic arthritis, osteomyelitis, bacteraemia in severe or delayed cases.
🔎 Investigations
- Culture on blood agar → smooth, grey, non-haemolytic colonies.
- Blood tests if systemic features (WCC, CRP, cultures).
💊 Management
- Immediate wound care: Vigorous irrigation + debridement.
- Delayed closure: Avoid primary closure of cat/dog bite wounds (esp. hand/face) to prevent trapping infection.
- Antibiotics:
- First line: Co-amoxiclav (amoxicillin–clavulanate).
- If penicillin allergy → doxycycline + metronidazole OR ceftriaxone (depending on severity).
- Tetanus & rabies prophylaxis → assess based on history and local guidelines.
💡 Exam pearl: Dog/cat bite cellulitis that fails to improve on flucloxacillin → think Pasteurella multocida.
First-line = Co-amoxiclav ✅.