Category Archives: Vibrio parahaemolyticus

RASFF Alert – Vibrio parahaemolyticus – Frozen Raw Shrimps

RASFFEuropean Food Alerts

Vibrio parahaemolyticus (in 4 out of 5 samples /25g) in frozen raw shrimps (Penaeus vannamei) from Vietnam, via the Czech Republic in Slovakia

Research – Effect of Ploidy on Vibrio parahaemolyticus and Vibrio vulnificus Levels in Cultured Oysters

Journal of Food Protection

Vibrio parahaemolyticus and Vibrio vulnificus are naturally occurring human pathogenic bacteria commonly found in estuarine environments where oysters are cultured. The use of triploid oysters has increased due to their rapid growth rate and because they maintain a high quality throughout the year. Previous work suggested levels of Vibrio spp. may be lower in triploid oysters than diploid oysters. Therefore, this study aimed to determine whether there is a difference in the abundances of V. parahaemolyticus and V. vulnificus between half-sibling diploid and triploid American oysters (Crassostrea virginica). In four trials, 100 individual oysters (either iced or temperature abused) were analyzed for V. parahaemolyticus and V. vulnificus by using direct plating followed by colony hybridization. Mean levels of V. parahaemolyticus in iced and abused diploid oysters were 3.55 and 4.21 log CFU/g, respectively. Mean levels in iced and abused triploid oysters were 3.49 and 4.27 log CFU/g, respectively. Mean levels of V. vulnificus in iced and abused diploid oysters were 3.53 and 4.56 log CFU/g, respectively. Mean levels in iced and abused triploid oysters were 3.54 and 4.55 log CFU/g, respectively. The differences in Vibrio spp. abundances between diploid and triploid oysters was not significant (P > 0.05). However, the differences across treatments were significant (P < 0.05), with the exception of V. parahaemolyticus levels in trial 3 (P = 0.83). Variation between individual oysters was also observed, with 12 of 808 measurements being outside of the 95th percentile. This phenomenon of occasional statistical outliers (“hot” or “cold” oysters) has been previously described and supports the appropriateness of composite sampling to account for inherent animal variability. In summary, the data indicate that abundances of V. parahaemolyticus and V. vulnificus are not dependent on the ploidy of cultured oysters but vary with the type of handling.

  • Vibrio spp. abundances in oysters are not dependent on ploidy.
  • Vibrio spp. abundances in oysters are dependent on handling treatment.
  • Identification of occasional “hot” or “cold” oysters supports composite sampling.

Canada – Vibrio parahaemolyticus: Canadian officials investigate outbreak in 4 provinces

Outbreak News Today

The Public Health Agency of Canada (PHAC) announced investigating  an outbreak of Vibrio parahaemolyticus infections occurring in four provinces.

Based on the investigation findings to date, exposure to shellfish has been identified as a likely source of the outbreak. Many individuals who became sick reported eating shellfish, mainly raw oysters, harvested from eastern coastal waters, before their illnesses occurred.

As of October 14, 2020, there are 21 confirmed cases of Vibrio parahaemolyticus illness in the following provinces: Saskatchewan (1), Quebec (7), New Brunswick (10), and Prince Edward Island (3). Individuals became sick between early July and mid-September 2020. One individual has been hospitalized. No deaths have been reported.

Research – Presence of Foodborne Pathogens in Seafood and Risk Ranking for Pathogens

Mary Ann Leibert

This study aims at examining the contamination of coliform bacteria, Escherichia coliListeria monocytogenesVibrio vulnificus, and Vibrio cholerae, which carry extremely serious risks to the consumer health, in 700 seafood belonging to 4 different (raw sea fish, raw mussels, raw shrimp, and raw squid) categories. The total number of samples was determined as 700. When the obtained results were viewed in total, they were found to be 48.14%, 18.71%, 8.57%, and 3.42% for coliform bacteria, E. coliL. monocytogenes, and V. vulnificus, respectively. V. cholerae, one of the factors studied, was not found. Conventional microbiological cultivation methods were used in the analysis stage as well as the real-time PCR method. This study aims at making a risk ranking modeling for consumer health based on product category and pathogens by interpreting the results of the analysis with statistical methods. According to the statistical analysis, significantly binary correlations were determined among some parameters that stimulate one another for reproducing. In the light of the obtained results of the study, it has been concluded that the studies of the most detailed examinations of the microbiological risks associated with seafood, forms of microbial pollution and microorganisms that cause deterioration in seafood and threaten consumer health and the path that their epidemiologies follow, are of primary importance to both protecting consumer health and obtaining safe and quality seafood.

Canada – N.B. declares outbreak of shellfish bacteria causing gastrointestinal illness – Vibrio parahaemolyticus

Global News CA

Food Illness - Vibrio

Image CDC

New Brunswick health officials have declared an outbreak of vibrio parahaemolyticus, a bacteria found in shellfish that causes gastrointestinal illness in humans.

The province says nine cases of vibrio have been confirmed. The average for New Brunswick is typically only two to three cases a year.

“I am advising all New Brunswickers to ensure that they obtain shellfish and other seafood from a licensed establishment or harvest shellfish from fishing zones which are currently open by Fisheries and Oceans Canada,” said N.B. chief of health Dr. Jennifer Russell in a news release.

Research – Surveillance of foodborne disease outbreaks in China, 2003–2017

Science Direct

Foodborne disease remains a major public health problem worldwide. To understand the epidemiology and changes of foodborne disease in China, data reported to the National Foodborne Disease Outbreak Surveillance System during 2003–2017 were collected. A total of 19,517 outbreaks, which resulted in 235,754 illnesses, 107,470 hospitalizations, and 1,457 deaths, were reported in this period. Of the 13,307 outbreaks with known etiology, 31.8% of outbreaks were caused by poisonous mushrooms, followed by Vibrio parahaemolyticus (11.3%), saponin (8.0%), Salmonella (6.8%), nitrite (6.4%), pesticide (4.8%), Staphylococcus aureus (4.2%) and Bacillus cereus (3.0%). Among 18,955 outbreaks with reported setting, 46.6% were associated with food prepared in a household, followed by 22.5% with food prepared in a restaurant, and 18.4% prepared in a canteen. Of the 13,305 outbreaks associated with a single food category, fungi (mainly poisonous mushroom) were the most commonly implicated food category, followed by meats, vegetables, aquatic animals, condiments, poisonous plants (such as saponin, tung oil or seed, aconite) and grains (such as rice, noodle, rice noodle). Analysis of foodborne disease outbreaks can provide insight into the most important causative agents and sources of foodborne disease, and assist public health agencies determine the high-risk etiology and food pairs, specific points of contamination and settings to reduce foodborne disease illnesses.

China – Durian grabbed from sunken vessel sicken 523 Guangxi villagers – Vibrio parahaemolyticus

The Standard

Food Illness

A total of 523 Chinese villagers suffered from food poisoning symptoms after eating durian from a capsized cargo ship in Guangxi on August 26, the local disease control center announced on Tuesday, the state media said.

A later investigation showed that they were infected with vibrio parahaemolyticus bacterium, which, when ingested, causes gastrointestinal illness in humans, and was probably caused by the durian becoming contaminated by sea water.
An announcement from the local government on August 27 said 101 of the villagers suffered from abdominal pains, diarrhea and vomiting while others only displayed mild symptoms. Nine people are currently in hospital,
Video clips circulating online showed the villagers rushing to the sea to try and recover durian floating on the sea water’s surface, after a cargo ship loaded with durian overturned around 200 meters away from the coast of Dongxing in Guangxi on August 26.
Local authorities tried to stop the villagers, but they still managed to recover some durian.
More common in the sea, vibrio parahaemolyticus bacterium is a microorganism that favors salty food, and is commonly found in food poisoning cases in coastal areas in the summer and autumn months, Guangxi Center for Disease Prevention and Control said.
It often lurks in fish, shrimp, crab, shellfish and other seafood, and occasionally spreads through salted products like pickles, seasoned meats and salted eggs. It is suspected the durian, soaked in sea water, could have been contaminated with the microorganism.
Experts said the incubation period for those infected with the bacterium ranges from 1 hour to 4 days, but lasts 10 hours in most cases. The symptoms resulting from its ingestion start quickly, and include chills, abdominal pains, nausea and vomiting, followed by fever, diarrhea, and watery or bloody stool.

Research – Escape artists: How vibrio bacteria break out of cells

Science Daily

Food Illness

Image CDC

As soon as the foodborne pathogen Vibrio parahaemolyticus infects a human intestinal cell, the bacteria are already planning their escape. After all, once it is in and multiplies, the bacterium must find a way out to infect new cells.

Now, UT Southwestern scientists have discovered the surprising route that V. parahaemolyticus takes during this exit — or egress — from cells. The bacteria, they report in the journal eLife, gradually modify cholesterol found in a cell’s plasma membrane, eventually weakening the membrane enough so that it can break through.

“The more we understand how bacteria are manipulating host cells at a molecular level, the more we understand how they cause disease,” says study leader Kim Orth, Ph.D., professor of molecular biology and biochemistry at UTSW and a Howard Hughes Medical Institute investigator. “Bacteria have many different mechanisms to escape, but this stood out because it’s an especially novel one.”


Research – Synergistic antibacterial effect of nisin, ethylenediaminetetraacetic acid, and sulfite on native microflora of fresh white shrimp during ice storage

Wiley Online

This study aims to investigate the effectiveness of using nisin, ethylenediaminetetraacetic acid (EDTA), and sulfite alone or in combination in reducing Vibrio parahaemolyticus Salmonella enterica , and Pseudomonas fluorescens in broth and native microflora on raw Pacific white shrimp during ice storage. Nisin (50 ppm), EDTA (20 mM), alone or in combination were used to test on the growth of parahaemolyticus enterica , and fluorescens in broth. Nisin (50 ppm), EDTA (20 mM), sodium metabisulfite (1.25 and 0.625%), ice; alone or in combination were used on shrimps during 1°C storage for 10 days. Microbial and chemical changes were analyzed during shrimp storage. First, the combination of nisin and EDTA exhibited antibacterial effects against parahaemolyticus enterica , and fluorescens in broth. Second, in shrimp preservation, the combination of nisin, EDTA, and sulfite at a low dose of 0.625% exhibited higher antimicrobial activity than did a high dose of sulfite (1.25%). Based on aerobic bacteria counts, psychrotrophic bacteria, and TVB‐N, shrimp treatment with combination of nisin, EDTA, and low‐dose sulfite were still acceptable within 10 days of storage. Based on our findings, nisin and EDTA can be used to reduce uses of sulfite for shrimp preservation in the future.

Research – Attributing human foodborne diseases to food sources and water in Japan using analysis of outbreak surveillance data


In Japan, strategies for ensuring food safety have been developed without reliable scientific evidence on the relation between foodborne infections and foods. The aim of this research was to provide information on the proportions of foodborne diseases caused by seven major causative pathogens ( Campylobacte r spp., Salmonella spp., EHEC, V. parahaemolyticus , Clostridium perfringens , Staphylococcus aureus , and Norovirus) attributable to foods using analysis of outbreak surveillance data. For the calculation of the number of outbreaks attributed to each source, simple-food outbreaks were attributed to the single-food category in question, and complex-food outbreaks were classified under each category proportionally to the estimated probability. Between 2007 and 2018, 8.730 outbreaks of foodborne diseases caused by seven pathogens were reported and another 6,690 (76.6%) were of “unknown source”. We observed fluctuations in the sources of foodborne diseases caused by the seven pathogens from 2013 to 2018 as follows: chicken products (92.9%, CI 92.6–92.9) for Campylobacter spp., beef products (40.1%, CI 38.2–41.2) and vegetables (39.3%, CI 38.2–41.2) for EHEC, eggs (22.8%, CI 14.9–31.9), chicken products (13,3%, CI 6.4–21.3) for Salmonella spp., finfish (86.3%, CI 62.5–95.8) and shellfish (13.7%, CI 4.2–37.5) for V. parahaemolyticus, grains and beans (47.2%, CI 31.2–62.5) for S. aureus, vegetables (69.3%, CI 50.8–79.7) and beef products (13.1%, CI 10.2–15.3) and chicken products (10.0%, CI 1.7–27.1) for C. perfringens , and shellfish (74.7%, CI 73.1–75.9) for Norovirus. In this study, we provide the best currently available basis to evaluate the link between foodborne diseases and foods. Additionally, our results reflected the effect of strict health regulations for raw beef during a given time period, and demonstrate the importance of controlling the contamination rate of Campylobacter spp. in chicken products at each step of the food supply chain.