Marine exposure and wounds: Which organism is least likely to cause wound infection after exposure to seawater or contaminated shellfish?

Introduction:
Marine and brackish water exposures can seed polymicrobial wound infections with specific Gram-negative organisms. This question examines knowledge of which listed pathogen is least associated with wound infections after seawater or shellfish exposure.

Given Data / Assumptions:

• V. vulnificus is notorious for necrotizing wound infections after seawater exposure.
• V. alginolyticus commonly causes otitis externa and wound infections in marine settings.
• Aeromonas species are linked to freshwater and brackish injuries but can be present in coastal environments.
• Shewanella algae can cause marine-associated soft-tissue infections.

Concept / Approach:
Identify the organism whose primary clinical association is not wound infection in marine exposures. V. cholerae is mainly an enteric pathogen transmitted via contaminated water/food causing cholera, not a typical wound pathogen.

Step-by-Step Solution:
Step 1: Map each organism to typical disease: V. vulnificus → severe wound sepsis; V. alginolyticus → ear/wound; Aeromonas → traumatic water-related wound infections; Shewanella → marine soft tissue infection.Step 2: Recognize V. cholerae primarily causes diarrheal disease, rarely implicated in wound infections.Step 3: Therefore, V. cholerae is least likely in this context.

Verification / Alternative check:
Case series emphasize V. vulnificus as a leading cause of rapidly progressive necrotizing infections after seawater injuries, whereas V. cholerae is infrequently reported outside the gastrointestinal tract.

Why Other Options Are Wrong:

• V. vulnificus: quintessential marine wound pathogen.
• V. alginolyticus: frequently linked to marine wound and ear infections.
• Aeromonas: well-known cause of water-exposure wounds, especially freshwater.
• Shewanella algae: documented cause of marine-associated cellulitis and ulcers.

Common Pitfalls:
Assuming all vibrios are enteric only; overlooking well-documented marine wound pathogens like V. vulnificus.

Final Answer:
Vibrio cholerae.