Category Archives: Vibrio parahaemolyticus

Research – Long-Term Depuration of Crassostrea virginica Oysters at Different Salinities and Temperatures Changes Vibrio vulnificus Counts and Microbiological Profile

Journal of Food Protection

Previous short-duration depuration studies with the eastern oyster (Crassostrea virginica) demonstrated difficulty in achieving significant naturally incurred Vibrio vulnificus population count reductions. The present study used long-duration depuration (14 days) at controlled temperatures (10 or 22°C) and salinities (12, 16, or 20 mg/g). All depuration temperature–salinity combinations significantly reduced V. vulnificus counts, with greatest reductions seen in 12 mg/g, 10°C seawater (2.7-log CFU/g reduction) and in 20 mg/g, 22°C seawater (2.8-log reduction). Mesophilic vibrios dominated the overall microflora of freshly harvested oysters, whereas refrigerated storage selected for psychrotrophic bacteria (Pseudomonas spp., Aeromonas spp., Shewanella spp., Psychrobacter spp.) as well as did depuration at 10°C (Pseudoalteromonas spp., Shewanella spp., Vibrio spp.). Depuration at 22°C retained dominance of mesophilic vibrios, including pathogenic species, followed by Shewanella spp., Pseudoalteromonas spp., and Photobacterium spp. Although aerobic plate counts were lower in 22°C depurated oysters (5.0 log versus 6.0 log) compared with 10°C, depuration at 10°C offered greater V. vulnificus population reductions than depuration at 22°C. This advantage was only seen at 12 mg/g salinity, with no impact at 16 and 20 mg/g salinities. No depuration treatment reduced V. vulnificus counts to nondetectable levels. Use of prolonged depuration may be a helpful intervention to control V. vulnificus populations in oysters.

RASFF Alert- Vibrio parahaemolyticus – Frozen Squid

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RASFF-Vibrio parahaemolyticus in frozen squid (Loligo spp.) from India in Greece

Research – How to kill pathogens on seafood

Food Processing

Controlled release antimicrobial film makes seafood safer.

Seafood may be contaminated with bacterial pathogens, such as Vibrio and Salmonella, which can survive long-term freezing conditions. Vibrio naturally occur in marine environments and Salmonella can contaminate seafood during production or processing and both are concerns for the seafood industry.

However, a solution may be at hand. A biodegradable, edible film made with plant starch and antimicrobial compounds may control the growth of foodborne pathogens on seafood, according to a group of international researchers.

Catherine Cutter, professor of food science, Penn State, explained, “We have the ability to develop a film with antimicrobial activity that can kill foodborne pathogens on food surfaces. Given the recent outbreaks that we have seen with a number of food products, coming up with something that can be used by the industry to kill microorganisms on the surfaces of food is a noble area of research to investigate.

Vibrio and Salmonella are somewhat susceptible to freezing,” Cutter said. “So, if you treat bacterial cells with antimicrobials and then freeze them, the approach can be more lethal.”

Freezing does not kill bacteria. However, when freezing food, ice crystals can form from the water in food. The ice crystals, Cutter said, can act like “daggers” and pierce the bacterial cell wall, causing damage to the cell.

Researchers used a blend of thermoplastic starch, a biodegradable polymer made from tapioca powder and a gelatin coating containing antimicrobials known as Nisin Z and lauric arginate (LAE).

 

Hong Kong – Test results on microbiological quality of poon choi all satisfactory

CFS

 

The Centre for Food Safety (CFS) of the Food and Environmental Hygiene Department today (November 26) announced the test results of a recently completed seasonal food surveillance project on the microbiological quality of poon choi. Thirty samples were collected and all passed the tests.

A CFS spokesman said, “As poon choi is popular for gatherings during winter and there were previous cases of bacterial food poisoning associated with poon choi, the CFS has continued to conduct a seasonal food surveillance project this year to assess the microbiological quality of poon choi. A total of 30 poon choi samples were collected from different retailers (including online retailers) for testing of common food poisoning organisms including Bacillus cereus, Clostridium perfringens, Salmonella, coagulase-positive staphylococci organisms and Vibrio parahaemolyticus.”

Despite the satisfactory results of all samples tested, the spokesman reminded people to be careful when purchasing and enjoying this seasonal delicacy. He advised consumers to order poon choi from licensed and reliable shops, avoid prolonged storage of poon choi at room temperature to reduce the risk of bacteria growth, reheat poon choi thoroughly before consumption, consume cooked or reheated poon choi as soon as possible or keep the food at temperatures above 60 degrees Celsius, and stop consuming the food if it tastes or smells abnormal.

“The public should also maintain a balanced diet and avoid eating too much food with high levels of energy, sugar, salt or fat,” the spokesman said.

He also appealed to the food trade not to entertain orders beyond handling capacity. Traders are reminded to check the quality of food and ingredients when they are delivered to them. In addition, to reduce the risk of food poisoning, they should avoid preparing food too far in advance and take note of the temperature in storing, transporting and preparing food.

“All food and food ingredients should be stored at safe temperatures while perishable items should be stored at 4 degrees C or below. The cooling time of cooked food should be reduced as far as possible, for example, by dividing food into smaller portions or placing it in shallow containers. When transporting hot poon choi, it should be kept at above 60 degrees C, and for chilled poon choi, it should be kept at 4 degrees C or below,” the spokesman said.

“Traders should also provide clear advice on the proper methods of storing and reheating of poon choi to consumers so as to further reduce the risk of food poisoning due to improper handling,” he added.

The CFS will continue its surveillance of poon choi available in the market to ensure food safety and protect the health of the public.

Japan – Food poisoning shuts sushi shops – Vibrio parahaemolyticus

The Japan News 

CDC Vibrio

TOKYO (Jiji Press) — Totoyamichi, a conveyor-belt sushi restaurant operator affiliated with Japan’s Skylark Holdings Co., has been shutting all 24 outlets since Monday after food poisoning occurred at some of them.

At least 39 customers have complained of food poisoning symptoms after eating at Totoyamichi restaurants.

Skylark reported the case only on its website while stopping short of holding a press conference. The restaurant group may thus come under fire for failing to fully explain the incident, analysts said.

According to Skylark, food poisoning symptoms, such as diarrhea and stomachache, were reported from customers who used eight Totoyamichi outlets in Tokyo and neighboring Kanagawa and Saitama prefectures between Aug. 31 and Sept. 3. The affected customers are recovering from their illness.

In a survey by Skylark, vibrio parahaemolyticus, a type of bacteria that causes stomachache and other symptoms, was detected from raw sea urchin at some outlets.Speech

Research -Occurrence of four pathogenic Vibrios in Chinese freshwater fish farms in 2016

Science Direct

The purpose of this survey was to investigate the distribution of major pathogenic Vibrio spp. (Vibrio parahaemolyticus, Vibrio alginolyticus, Vibrio vulnificus and Vibiro cholerae) in Chinese freshwater fish farms. In total, 4,064 samples of freshwater fish, water and sediment were collected from 12 provinces covering every quarter in 2016. The occurrence of Vibrios was as follows: V. cholerae (10.33%), V. parahaemolyticus (3.89%), V. alginolyticus (1.24%) and V. vulnificus (0.76%). Among 158 confirmed V. parahaemolyticus isolates, 44 isolates (27.85%) had virulence genes (trh/tdh). Among 420 confirmed V. cholerae isolates, 4 were the O1 stains and 4 were the O139 strains. Out of 112 freshwater farms, 58.93% had Vibrios-positive samples. The rates of Vibrios-positive samples from May to October (12.45%∼35.20%) were higher than those in other months (0.00%∼8.07%). Compared the environment factors of Vibrios positive and negative water samples, there was a significantly difference in temperature (P<0.01), while no significant difference in salinity and pH value (P>0.05). In summary, the study presents comprehensive contamination data on the occurrence of four major pathogenic Vibrios in freshwater aquaculture of China for the first time, and the results indicate that Vibrios are widely distributed in aquaculture environment and a further risk assessment is needed to conduct.

USA – Texas warns public of Vibrio risk

Outbreak News Today 

CDC Vibrio

Image Cdc Enter a caption

 

Texas health officials are warning the public about the increased risk of Vibrio infections naturally found in coastal water.

Most infections occur between May and October, when the warmer water temperatures in the Gulf of Mexico promote the growth of these bacteria.

People can become ill after eating raw or undercooked contaminated seafood, particularly oysters, or when a person has an open wound that is exposed to seawater. Illness due to eating raw or undercooked seafood usually includes gastrointestinal symptoms such as vomiting, diarrhea, abdominal pain, nausea, fever, and chills. These symptoms frequently occur within 24 hours of eating and last approximately three days. Wound infections can cause redness, swelling, large blisters on the skin, skin ulcers, and, in serious cases, may even lead to limb amputation or death. People with a weakened immune system, liver disease, diabetes, cancer, or other chronic diseases or who have decreased gastric acidity are at highest risk for severe illness.