Plesiomonas Shigelloides (Food Poisoning)


What is Plesiomonas shigelloides?

Plesiomonas shigelloides is a member of the family Vibrionaceae.  It is a Gram negative, motile, facultatively anaerobic, oxidaase positive bacterium.  Most human Pleasiomonas shigelloides infections are suspected to be waterborne in nature.  The organism maybe present in unsanitary water which has been used for drinking water, recreational water or water used to rinse foods that are consumed without cooking or heating.    Pleasiomonas shigelloides has been isolated from freshwater fish and raw shellfish such as shrimp and oysters and a variety of animals including cattle, goats, swine, cats, dogs, snakes and toads.


What are the symptoms of Plesiomonas shigelloides?

People exposed to these bacteria may experience mild self-limiting gastroenteritis.  The most common symptoms are diarrhea, nausea, vomiting, fever, chills and abdominal pain.  Diarrhea is usually watery and non-bloody.

The symptoms may appear from 20 to 24 hours after consumption of contaminated food or water.  The symptoms may last from 1 to 7 days.

Most infections are so mild that individuals do not seek medical treatment.  When treatment is indicated by their health care provider infections are treated with and respond well to antibiotics.


Where is Pleasiomonas shigelloides found and how is it spread?

Most human infections are suspected to be waterborne.  Pleasiomonas shigelloides infections occur in the summer months and correlate with environmental contamination of freshwater (rivers, streams, ponds) and are generally found in a tropical freshwater environment.  The usual route of transmission of the organism in sporadic or epidemic cases is by ingestion of contaminated water or raw shellfish.  It has also been found associated with aquariums and fish tanks.


How do you prevent Pleasiomonas shigelloides infections?

  • Hand washing is the best prevention. Make sure hands are properly washed, using soap and water for at least 15 seconds, after using the washroom, handling diapers and before and after preparing or serving food.
  • Clean and sanitize diaper changing area after each use
  • Drink water from a safe supply.  When traveling, boil water for at least 1 minute if you are unsure of the supply or use bottled water.  Remember that ice cubes made from contaminated water may also carry the parasite.
  • Avoid eating raw shell fish harvested from unknown sources.
  • When cleaning an aquarium/ fish tank ensure sinks are cleaned afterwards and wash hands properly using soap and water for at least 15 seconds.
  • If ill with diarrhea, avoid preparing or handling food.


This page provides basic information only. It must not take the place of medical advice, diagnosis or treatment. Always talk to a health care professional about any health concerns.

Source:  US Department of Health Bad Bug Book, Foodborne Pathogenic Microorganisms


For Further Information

Call the Infectious Disease Program: (807) 625-5900

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Health Topic
Diseases & Infections