Pasteurella multocida

1. GC 178 (An ugly wound): Animal bite wounds are a classic setting for Pasteurella multocida infection — the lecture emphasises wound infection pathogens and antiseptic technique; cat/dog bites are a core scenario ^[1].

2. GC 105 (Medically important microbes): Pasteurella multocida is listed among medically important G−ve organisms every doctor should know — emphasised as the prototypical bite wound organism alongside Capnocytophaga ^[1].

3. GC 106 (Practical issues in antibiotic use): Co-amoxiclav is the empirical antibiotic of choice for animal bite wounds — this is directly examinable as a prescribing question; the lecture warns against using cephalexin alone ^[1].

4. GC 098 (Antibiotic prophylaxis): Cat bites warrant prophylactic antibiotics due to high infection rates (~50%) — the lecture frames prophylaxis indications by wound type, location, and host factors ^[1].

5. AOS Microbiology material: Pasteurella is a "classic vignette" organism — very short stem required: animal bite + rapid-onset cellulitis = Pasteurella multocida ^[2].

• Onset timing is the key discriminator: Pasteurella causes infection within 12–24 hours of the bite. If the vignette says infection developed "3 days later" after a dog bite, consider Staphylococcus aureus, Streptococcus, or Capnocytophaga instead.
• Cat bite vs dog bite: Cat bites are deeper puncture wounds, higher inoculation → higher Pasteurella infection rate. Dog bites → broader polymicrobial flora, also risk of Capnocytophaga canimorsus.
• Asplenic patient + dog bite + fulminant sepsis = Capnocytophaga canimorsus (NOT Pasteurella — this is a common wrong answer).
• Cat scratch + regional lymphadenopathy (subacute, weeks) = Bartonella henselae (cat-scratch disease), NOT Pasteurella.
• Human bite + "clenched fist" injury = Eikenella corrodens, NOT Pasteurella.
• First-generation cephalosporin resistance: A favourite wrong-answer trap — students may choose cephalexin for "skin infection," but Pasteurella is intrinsically resistant. Always pick co-amoxiclav.

No directly relevant past paper questions concerning Pasteurella multocida were identified in the indexed Fourth Summative papers (2016–2025 MCQ, SAQ, and Minicase papers). The organism has not appeared as a named answer or stem pathogen in the available indexed past paper context.

However, note that the 2021 Fourth Summative SAQ Q12 ^[3] asks about organisms in immunocompromised settings (post-BMT), and the 2018 Fourth Summative Minicase ^[4] asks to name organisms causing specific infections — students should be prepared to list Pasteurella in any bite wound or soft tissue infection scenario if it appears in future papers.