Vibrio parahaemolyticus: Potential threat to consumer health

V. parahaemolyticus is a Gram-negative, straight, sometimes curved, bacillus that belongs to the family of Vibrionaceae. These bacteria are widespread in the marine environment, which is their main reservoir. V. parahaemolyticus occurs in estuaries and warm seawaters along the coasts of many continents. It is the most frequent cause of food poisoning in Asian countries, but only sporadically causes this type of health problems in Europe. This microorganism is halophilic, and its presence in seawaters is closely connected with seasonality. Only about 1% of V. parahaemolyticus occurring in the natural environment is pathogenic for people. The strains belonging to pandemic serotypes O3:K6, O1:KUT, O1:K25, O4:K68 are considered as the most pathogenic bacteria. The major sources of pathogenic strains are fish and seafood. Infection usually results from eating contaminated food, especially raw or undercooked food of marine origin. Man can be an asymptomatic carrier, and bacteria excreted with stool cause secondary environmental contamination. Clinical symptoms connected with gastroenteritis usually include severe watery diarrhoea, nausea and abdominal cramps. In the acute form of the disease, hemorrhagic gastroenteritis occurs. Moreover, severe infections may lead to complications connected with septicemia, which sometimes lead to death. Extraintestinal V. parahaemolyticus infections are rare and usually occur as wound infections. Culture methods that are commonly used for the identification of V. parahaemolyticus are laborious and time-consuming, and their results are not always clear. Recently, several DNA-based methods of detecting pathogenic V. parahaemolyticus have been developed. They are highly sensitive and specific, as well as faster than traditional microbiological analyses.