Which organism is commonly involved in freshwater wound infections and is a Gram-negative rod?

• A. Aeromonas hydrophila
• B. Plesiomonas shigelloides
• C. Vibrio vulnificus
• D. Yersinia enterocolitica

Answer: (A)

Freshwater wound infections are most often caused by bacteria that thrive in aquatic environments. Aeromonas hydrophila is a Gram-negative rod commonly found in fresh water and is a classic culprit in wounds exposed to such surroundings. It can produce a range of infections from skin cellulitis to more invasive disease, especially in people with underlying health issues. While Plesiomonas shigelloides is also associated with freshwater and can cause gastroenteritis, it is less frequently implicated in wound infections. Vibrio vulnificus, by contrast, is tied to saltwater and marine exposures, making it a coastal wound pathogen rather than a freshwater one. Yersinia enterocolitica is typically linked to foodborne illness and not to freshwater wound infections. Thus, Aeromonas hydrophila best fits the scenario.