Vibrio vulnificus bacteria, computer illustration. This Gram-negative rod- shaped motile bacteria is found in sea water. It can cause disease if ingested in contaminated seafood, or if an open wound is exposed to contaminated water. In healthy individuals it causes vomiting, diarrhoea and abdominal pain, or dermatitis. In those with a compromised immune system or liver disease it can cause fever, decreased blood pressure, blistering skin lesions and septicaemia, and can be fatal.