Category Archives: Vibrio vulnificans

RASFF Alert – Vibrio vulnificus – Frozen Wild Giant Tiger Shrimps

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RASFF – Vibrio vulnificus (present /25g) in frozen wild giant tiger shrimps (Penaeus monodon) from Vietnam in France

RASFF Alert -Vibrio vulnificus – Frozen Shrimps

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RASFF – Vibrio vulnificus (presence /25g) in frozen shrimps (Penaeus vannamei) from Honduras in the Netherlands

Research – Vibrio spp. from Yesso scallop (Patinopecten yessoensis) demonstrating virulence properties and antimicrobial resistance

Wiley Online Library

Abstract

We report the prevalence and characterization of Vibrio spp. isolated from marketed Yesso scallop (Patinopecten yessoensis) in Korea. A total of 30 isolates including, V. parahaemolyticus (n = 2), V. alginolyticus (n = 9), V. fluvialis (n = 7), V. diabolicus (n = 7), V. anguillarum (n = 4) and V. aestuarianus (n = 1) were isolated and identified. The phenotypic pathogenicity tests demonstrated that, 18 (60%), 21 (70%), 18 (60%), 7 (23%), 22 (73%), 21 (70%), 9 (30%), and 11 (33%) of the isolates were positive for DNase, protease, gelatinase, lipase, phospho‐lipase, amylase, slime production, and haemolysis, respectively. PCR assays revealed the prevalence of toxR, tlh, VAC, vfh, hupO, and VPI genes among the isolates with varying combinations. A close genetic affinity among V. alginolyticus and V. diabolicus strains was observed. Also the virulence genes specific to one Vibrio species were detected among other species as well. In addition, 29/30 (97%) isolates were multidrug resistant, while higher resistance rates were shown for ampicillin, colistin, vancomycin, and cephalothin. The results imply that the scallops in Korean markets harbor Vibrio spp., which are potentially virulent and multidrug resistant, thus their public health implications should not be underrated.

Practical applications

For many decades, vibrios are known for its importance in seafoodborne illnesses. Yesso scallop is the most popular and extensively cultured scallop variety in Korea. Therefore, we sought to assess the marketed fresh Yesso scallops for the prevalence and molecular characterization of Vibrio species. A total of 30 strains were isolated and identified by a series of biochemical tests, subsequent gyrB gene sequencing and phylogenetic analyses. Six Vibrio spp. were identified with V. alginolyticus as the most prevalent. Interestingly, V. alginolyticus was genetically similar to V. diabolicus. Besides, the virulence genes specific to V. alginolyticus and V. parahaemolyticus were observed in other species as well. It suggests that the detection of the species‐specific genes does not ensure the correct identification of pathogenic vibrios. Further, the occurrence of V. parahaemolyticus‐specific virulence genes in other Vibrio spp. potentially complicates the correct tracking of V. parahaemolyticus infections. In addition, 73% of these Vibrio spp. isolates showed multiple antibiotic resistance (MAR) indices higher than 0.2, which signifies their high risk of infection. Collectively, these results provide important evidence that not only the well‐known pathogenic vibrios like V. parahaemolyticus, but also other Vibrio spp. can act alike because of their similar characteristics.

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.

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).

 

USA – Vibrio vulnificus in Florida in 2018

Outbreak News Today

CDC Vibrio

Florida state health officials have reported 39 Vibrio vulnificus cases through Dec. 14, down from last year’s total of 50. Of this total, nine fatalities have been reported.

Lee County saw the most with four cases, while nine counties reported two cases each. Deaths were reported from Hillsborough (2), Dade, Indian River, Jackson, Okaloosa, Sarasota, Volusia and Walton counties.

People can get infected with Vibrio vulnificus when they eat raw shellfish, particularly oysters. The bacterium is frequently isolated from oysters and other shellfish in warm coastal waters during the summer months. Since it is naturally found in warm marine waters, people with open wounds can be exposed to Vibrio vulnificus through direct contact with seawater. There is no evidence of person-to-person transmission of Vibrio vulnificus.

Vibrio vulnificus can cause disease in those who eat contaminated seafood or have an open wound that is exposed to warm seawater containing the bacteria. Ingestion of Vibrio vulnificus can cause vomiting, diarrhea and abdominal pain. Vibrio vulnificus can also cause an infection of the skin when open wounds are exposed to warm seawater; these infections may lead to skin breakdown and ulcers.

USA – Flooding from Hurricane Michael creates food safety issues across South

Food Safety News

Strong winds and heavy rain continue to wreak havoc across parts of the South today as Hurricane Michael meanders out of Georgia and heads up the mid-Atlantic Coast.

In addition to the devastating damage that is immediately visible today, less obvious hazards in the wake of the massive storm are expected to last weeks. Food safety dangers come in various forms and can cause severe illnesses and deaths as floodwaters recede.

Among the most vulnerable foods are fresh fruits and vegetables. They are breeding grounds for pathogens when power outages cause the loss of refrigeration and temperature control. Fresh produce that comes into contact with floodwater can be instantly contaminated with a wide range of bacteria, viruses and parasites.

The toxic composition of floodwater is such a serious food safety hazard that federal law prohibits the sale, distribution or donation of any produce or other food crops from fields that are flooded. Special inspections are required before such crops can even be used for animal feed. 

USA Today

Hurricane Michael leaves behind a treacherous, dangerous landscape that will likely pose risks to human health for weeks to come, experts say.

The water itself can carry bacteria and viruses that pose a major health hazard.

Among the medical dangers are cholera, Hepatitis A and vibriosis, said Dr. Robert Glatter, an emergency room physician at Lenox Hill Hospital in New York City. Glatter said storm victims need to stay focused on staying healthy while they await recovery efforts. That may mean not rushing outside as soon as the skies clear.

“Don’t panic— try to take things one step at a time when you feel overwhelmed,” he said.