3.16 Pasteurella Multocida

Microbiology review for the USMLE Step 1 exam

• Pasteurella multocida is a gram-negative coccobacillus that commonly causes infection following animal bites or scratches
• Classic presentation is a young male with swollen, red, and tender skin at the site of the bite or scratch
• Symptoms develop rapidly, usually within 3-48 hours after injury
• In rare cases, infection can progress to necrotizing fasciitis or bacteremia
• Diagnosis is made clinically using patient history and symptoms
• Treatment of choice is amoxicillin-clavulanate, and infections usually resolve with little complications when treated with antibiotic