Which of the following is an anaerobic pathogen commonly associated with cat bite abscesses?

• A. Porphyromonas
• B. Escherichia coli
• C. Staphylococcus aureus
• D. Streptococcus pneumoniae

Answer: (A)

Cat bites introduce bacteria from the animal’s mouth, and abscesses often arise from anaerobic bacteria that thrive in the low-oxygen environment of a closed wound. Porphyromonas is an anaerobic gram-negative rod that is a common part of oral flora and is frequently implicated in bite-wound infections, particularly cat bites, contributing to abscess formation. The other organisms listed don’t fit this pattern: E. coli is a gut-associated organism and is typically a facultative anaerobe; Staphylococcus aureus is a common skin wound pathogen but not specifically an anaerobic oral bite pathogen; Streptococcus pneumoniae is a respiratory bacterium and not part of cat bite oral flora.