A respiratory bacterium is accidentally introduced into a deep puncture wound. To assess the risk of successful colonization in the wound you should analyze which of the following collections of factors together?

• A. Local oxygen tension, presence or absence of surface receptors compatible with the bacterium’s adhesins, local innate immune factors (e.g., neutrophil influx), and whether the wound environment provides nutrients and pH suitable for the respiratory bacterium.
• B. Only the bacterium’s capacity to form spores, because spore-forming ability is the single factor that determines whether any microbe can colonize a sterile wound regardless of receptor compatibility or immune response.
• C. Whether the bacterium previously colonized the nasal cavity of the patient, since prior colonization at any site automatically protects that same microbe from establishing in a wound due to cross-protective mucosal immunity.
• D. The sunlight exposure at the time of injury and the patient’s blood type alone, because colonization depends exclusively on UV-mediated killing and ABO antigens present at the wound surface.

Answer: (A)