Raw is risky: Searching for answers behind Vibrio-in-raw-oyster outbreaks

Michael Casey of The Charlotte Observer reports that for the past 25 years, researcher Stephen Jones has tried to understand the threat that bacteria may pose to oysters in New Hampshire’s Great Bay estuary. He often couldn’t get funding to study the problem. But that is beginning to change as scientists notice “something is going on.”

Oyster-Vancouver, B.C.- 07/05/07- Joe Fortes Oyster Specialist Oyster Bob Skinner samples a Fanny Bay oyster at the restuarant. Vancouver Coastal Health now requires restaurants to inform their patrons of the dangers of eating raw shellfish.  (Richard Lam/Vancouver Sun)   [PNG Merlin Archive]

Scientists are recognizing that a waterborne disease sickening tens of thousands of people each year is associated with warmer waters of the Gulf of Mexico moving northward, partly due to climate change. The problem is extremely rare in New Hampshire and neighboring Maine, but scientists have seen cases elsewhere in New England and expect it to become a bigger problem.

Cases of human illness have been piling up since Sept. in Florida, Massachusetts and Western Canada.

“We have this situation in the northern part of the United States and other cooler climates where people haven’t thought this had been a problem,” said Jones, of the Northeast Center for Vibrio Disease and Ecology at the University of New Hampshire. “In the last 10 or 20 years, it’s become very apparent that there is something going on.”

In a paper in the science journal PLOS One, Jones and other scientists reported their findings that illnesses from vibrio bacteria have jumped significantly in New England — from five cases in 2000 to 147 in 2013. Disease-causing bacteria can contaminate oysters, leading to infections such as diarrhea, vomiting and abdominal pain.

Jones and his colleague, Cheryl Whistler, concluded that warmer waters in the Great Bay, higher salinity and the presence of chlorophyll all contributed to higher concentrations of one of the more common vibrio species that makes people sick — vibrio parahaemolyticus. The researchers are hoping their findings will serve as the foundation of an early warning system for the region’s booming oyster industry.

oysters-grillCurrently, all experts can do is monitor the waters and rapidly cool harvested oyster to halt bacteria growth.

An August report in the Proceedings of the National Academy of Sciences found that warming waters were linked to waterborne food poisoning, especially from eating raw oysters.

“There is similar reporting in Alaska where it has been found that increased cases have been occurring where it has not been reported before because of the temperature rise,” said the study’s lead author, Rita Colwell, of the University of Maryland.

The industry has welcomed Jones and Whistler’s work, noting that outbreaks like the one that occurred last month in Massachusetts need to be avoided. Nearly 75 people were sickened.

“When you are involved with a recall because people have gotten sick, you are a losing tremendous amount of money and a tremendous amount of credibility,” said Tom Howell, president of Spinney Creek Shellfish Inc., in Eliot, Maine, which harvests oysters from the Great Bay. A predictive model would allow the industry to move more aggressively to avoid an outbreak, he said.

But Howell and Chris Nash, New Hampshire’s shellfish program manager, said that day could be far off.

“We are still learning what seems to trigger these pathogenic strains to multiply … We don’t have that knowledge yet and it may be that we never do,” Nash said. “We are talking about biological organisms … They react to their environment different, the same way humans do.”

OysterFest in Wellfleet MA to go on, without raw oysters, after 75 ill with noro

I’ve eaten exactly one raw oyster ever.

It was at a reception for a food safety meeting in New Zealand.

I picked up the shell, dumped the contents (salt water and a slimy shellfish meat) into my mouth, getting about 50% of it on my shirt. I spent the rest of the night smelling like the beach.raw_oyster

I didn’t get noro from the bivalve experience. According to capecod.com 75 folks around Cape Cod, MA are ill with norovirus after eating raw oysters harvested in a month that ends in ‘r.’

The state has closed all shellfish beds in Wellfleet Harbor following an outbreak of suspected norovirus believed to be linked to shellfish from that area.

It comes just two days before the Wellfleet OysterFest, which attracts tens-of-thousands of people to the Outer Cape.

An official from the festival said the event will go on planned, but without any raw shellfish.

The Massachusetts Department of Public Health issued the ban Thursday afternoon after receiving reports of approximately 75 suspect cases of norovirus over the past two days.

A statement from the DPH said they were all primarily associated with eating raw shellfish at weddings and restaurants in the Outer Cape area.

All shellfish harvesters in the area and Town of Wellfleet officials have been notified about the closure.

All affected shellfish that was harvested on or after September 26 has been recalled and ordered not to be used.

Minneapolis sees rise in foodborne illness from nororvirus, Vibrio in oysters

When I think Minnesota, I think raw oysters.

No, I never think that about anywhere.

raw.oysters.minnJeremy Olson of the Star Tribune reports that city health inspectors in Minneapolis are investigating a summer increase in foodborne illnesses related to norovirus and Vibrio, a bacteria found in raw oysters.

The increases were highlighted in the city’s “food establishment” newsletter, released Thursday.

“The reason for the spike in norovirus outbreaks is not known,” the advisory stated. “The Vibrio outbreaks are due to higher concentrations of bacteria in some oyster beds during the summer.”

Cases of norovirus, a highly contagious bug that causes severe vomiting and diarrhea, are not required to be reported to the Minnesota Department of Health, but the state agency has received reports of a slight uptick that is unusual for this time of year.

Raw is risky: Study links global warming to rise in waterborne illnesses

Rising global temperatures are clearly linked to increasing waterborne food poisoning, particularly from eating raw oysters, along with other nasty infections, a new study shows.

Oyster-Vancouver, B.C.- 07/05/07- Joe Fortes Oyster Specialist Oyster Bob Skinner samples a Fanny Bay oyster at the restuarant. Vancouver Coastal Health now requires restaurants to inform their patrons of the dangers of eating raw shellfish. (Richard Lam/Vancouver Sun) [PNG Merlin Archive]

About a dozen species of vibrio bacteria make people sick from eating raw or undercooked seafood or drinking or swimming in tainted water. It also causes cholera, although that was not the focus of the research.

Lab-confirmed vibrio infections in the United States have increased from an average of about 390 a year from the late 1990s to an average of 1,030 in recent years, according to the Centers for Disease Control and Prevention. But most cases aren’t confirmed by tests and reported.

“It’s a remarkable increase on an annual basis,” said study lead author Rita Colwell of the University of Maryland, a top microbiologist who used to head the National Science Foundation.

The study examined Europe and North America, but the most consistent tracking of vibrio illnesses were in the United States. The CDC blames about 100 deaths a year on vibrio on average.

Even Alaska, where such outbreaks used to be unheard of because the bacteria needs warm water, is getting cases from people eating vibrio-infected oysters, Colwell said. Her study, published in Monday’s Proceedings of the National Academy of Sciences , highlights an unprecedented wave of vibrio illnesses from swimming in northern Europe during heat waves in 1994, 1997, 2003, 2006 and 2010.

Climate influence on Vibrio and associated human diseases during the past half-century in the coastal North Atlantic

22.jun.16

DOI: 10.1073/pnas.1609157113

Vezzulli, C. Grande, P.C. Reid, P. Hélaouët, M. Edwards, M.G. Höfle, I. Brettar, R.R. Colwell, C. Pruzzo

http://www.pnas.org/content/early/2016/08/02/1609157113.abstract

Climate change is having a dramatic impact on marine animal and plant communities but little is known of its influence on marine prokaryotes, which represent the largest living biomass in the world oceans and play a fundamental role in maintaining life on our planet. In this study, for the first time to our knowledge, experimental evidence is provided on the link between multidecadal climatic variability in the temperate North Atlantic and the presence and spread of an important group of marine prokaryotes, the vibrios, which are responsible for several infections in both humans and animals. Using archived formalin-preserved plankton samples collected by the Continuous Plankton Recorder survey over the past half-century (1958–2011), we assessed retrospectively the relative abundance of vibrios, including human pathogens, in nine areas of the North Atlantic and North Sea and showed correlation with climate and plankton changes. Generalized additive models revealed that long-term increase in Vibrio abundance is promoted by increasing sea surface temperatures (up to ∼1.5 °C over the past 54 y) and is positively correlated with the Northern Hemisphere Temperature (NHT) and Atlantic Multidecadal Oscillation (AMO) climatic indices (P < 0.001). Such increases are associated with an unprecedented occurrence of environmentally acquired Vibrio infections in the human population of Northern Europe and the Atlantic coast of the United States in recent years.

Raw is risky: Canada reports 1st case this year of illness linked to eating raw oysters

CBC News reports British Columbia has recorded its first case this year of someone being sickened by eating raw oysters contaminated with Vibrio bacteria.

oysters.grillThe B.C. Centre for Disease Control (BCCDC) said the illness was reported June 30 in the Vancouver area.

Vibrio parahaemolyticus bacteria grow in seawater and can end up in shellfish like oysters and clams. When water temperatures rise in the summer, the accumulations of the naturally occurring bacteria increase to the point that eating undercooked shellfish can give people nausea, fever and diarrhea.

Last year’s outbreak of the Vibrio-caused illness was the biggest in Canadian history and sickened at least 73 British Columbians. Sixty of the illnesses were due to eating contaminated raw or undercooked B.C. oysters in restaurants. The other 13 illnesses were traced to exposure to seawater with high levels of the bacteria.

At the height of the outbreak last summer, Vancouver Coastal Health ordered restaurants not to serve raw oysters harvested from B.C. waters and the Canadian Food Inspection Agency issued a food recall for B.C. oysters. 

“Eating raw shellfish increases your risk of Vibrio and other infections,” said Dr. Eleni Galanis, epidemiologist at the BCCDC, in a release.  

“It’s best to eat them cooked, but if you choose to eat raw shellfish like oysters, then understand the risks and take steps to reduce your likelihood of illness.”

Meanwhile, Florida health officials have reported 13 Vibrio vulnificus cases as of July 5, including four fatalities thus far in 2016.

Last year, Florida saw 45 cases and 14 deaths, the most since 2003.

Healthy individuals typically develop a mild disease; however, Vibrio vulnificus infections can be a serious concern for people who have weakened immune systems, particularly those with chronic liver disease.

Oyster-Vancouver, B.C.- 07/05/07- Joe Fortes Oyster Specialist Oyster Bob Skinner samples a Fanny Bay oyster at the restuarant. Vancouver Coastal Health now requires restaurants to inform their patrons of the dangers of eating raw shellfish.  (Richard Lam/Vancouver Sun)   [PNG Merlin Archive]

So don’t be a drunk and eat raw.

I BBQ them, and prefer scallops on the half-shell.

In other Virbrio news, UT Southwestern Medical Center researchers have uncovered a mechanism that a type of pathogenic bacteria found in shellfish use to sense when they are in the human gut, where they release toxins that cause food poisoning.

The researchers studied Vibrio parahaemolyticus, a globally spread, Gram-negative bacterium that contaminates shellfish in warm saltwater during the summer. The bacterium thrives in coastal waters and is the world’s leading cause of acute gastroenteritis.

“During recent years, rising temperatures in the ocean have contributed to this pathogen’s worldwide dissemination,” said Dr. Kim Orth, Professor of Molecular Biology and Biochemistry at UT Southwestern and senior author of the study, published today in the online journal eLife.

About a dozen Vibrio species cause infection in humans, according to the Centers for Disease Control and Prevention, and Vibrio parahaemolyticus is one of the three most common culprits. Vibrio infections cause an estimated 80,000 illnesses and 100 deaths in the United States every year.

The study found that two proteins made by Vibrio parahaemolyticus work together to detect and capture bile salts in the intestines of people who eat raw or undercooked seafood containing the bacteria.

“When a person eats, acids in the stomach help break down the meal, and bile salts in the intestine aid in the solubilization of fatty food. When humans eat raw or undercooked shellfish contaminated with Vibrio parahaemolyticus, the bacteria use those same bile salts as a signal to release toxins,” said Dr. Orth, also an Investigator with the Howard Hughes Medical Institute (HHMI), holder of the Earl A. Forsythe Chair in Biomedical Science, and a W.W. Caruth, Jr. Scholar in Biomedical Research. Dr. Orth studies the strategies that bacterial pathogens use to outsmart their host cells.

Evidence is increasing that several bacterial pathogens that cause gastrointestinal illness, including the extremely toxic Vibrio cholerae, sense bile salts. But until now, the mechanism that those pathogens use for doing this has remained unknown, Dr. Orth said. In previous studies, only one bacterial gene had been implicated in receiving and transmitting the gut-sensing signal, Dr. Orth said.

“We discovered that not one, but two genes are required for Vibrio to receive the bile salt signal. These genes encode two proteins that form a complex on the surface of the bacterial membrane. Using X-ray crystallography, we found that these proteins create a barrel-like structure that binds bile salts and receives the signal to tell the bacterial cell to start making toxins,” she said.

Future experiments will aim to understand how binding of bile salt by this protein complex induces the release of toxins.

“Ultimately, we want to understand how other pathogenic bacteria sense environmental cues to produce toxins. With this knowledge, we might be able to design pharmaceuticals that could prevent toxin production, and ultimately avoid the damaging effects of infections,” she said.

The receptor pair could possibly act as a model to discover sensors in other bacteria where pharmaceuticals might be more applicable, Dr. Orth said, adding “we are in the early stages of this research.”

Co-lead authors were graduate student Peng Li and research scientist Dr. Giomar Rivera-Cancel, both in Molecular Biology. Other contributing authors included Dr. Lisa Kinch, an HHMI bioinformatics specialist; Dr. Dor Salomon, postdoctoral researcher; Dr. Diana Tomchick, Professor of Biophysics and Biochemistry and Director of the Structural Biology Core Facility; and Dr. Nick Grishin, Professor of Biophysics and Biochemistry, an HHMI Investigator, and a Virginia Murchison Linthicum Scholar in Biomedical Research.

The research was supported by the National Institutes of Health, the Welch Foundation, the Department of Energy, and the HHMI.

And finally, bacterial infections from various organisms including Vibrio sp. pose a serious hazard to humans in many forms from clinical infection to affecting the yield of agriculture and aquaculture via infection of livestock. Vibrio sp. is one of the main foodborne pathogens causing human infection and is also a common cause of losses in the aquaculture industry. Prophylactic and therapeutic usage of antibiotics has become the mainstay of managing this problem, however this in turn led to the emergence of multidrug resistant strains of bacteria in the environment; which has raised awareness of the critical need for alternative non antibiotic based methods of preventing and treating bacterial infections. Bacteriophages – viruses that infect and result in the death of bacteria – are currently of great interest as a highly viable alternative to antibiotics. This article provides an insight into bacteriophage application in controlling Vibrio species as well underlining the advantages and drawbacks of phage therapy.

Insights into bacteriophage application in controlling Vibrio species

Front. Microbiol. | doi: 10.3389/fmicb.2016.01114

http://journal.frontiersin.org/article/10.3389/fmicb.2016.01114/abstract

Vengadesh Letchumanan,  Kok Gan Chan,  Priyia Pusparajah,  Surasak Saokaew,  Acharaporn Duangjai,  Bey Hing Goh,  Nurul-Syakima Ab Mutalib and  Learn-Han Lee

Fancy food ain’t safe food: Oysters at Wimbledon edition

Oysters are no longer being served at Wimbledon after a bout of food poisoning at a luxury hospitality tent chefed by the Roux family.

novak djokovic-cropped_1e5jl4dpdlhai17s03p0ksxskiAccording to the Daily Mail, the Gatsby Club’s exclusive clientele pay up to £5,000 for corporate packages which include a champagne reception and a three-course meal prepared by Britain’ s first celebrity chef, Albert Roux, 80.

And with such steep prices, guests are also offered a complimentary bar and oysters upon arrival.

But customers may no longer be getting their money’s worth after organisers were forced to suspend serving the delicacy when a number of guests reported falling sick.

One customer, who did not want to be named, said he was warned about the bout of sickness after dining there this week.

He said: ‘A friend of mine who is a steward rang me up to find out if we were okay.

‘He said over 100 people had been poisoned and they reckoned it was the oysters.

‘We ate at the Gatsby Club last year and it was excellent, but people need to know if they’re spending this much money.’

A Wimbledon spokesperson would not confirm the exact number of people that were effected but said it was ‘less than half’ of 100.

WGS, Vibrio and traceback in oysters

In the summer of 2010, Vibrio parahaemolyticus caused an outbreak in Maryland linked to the consumption of oysters. Strains isolated from both stool and oyster samples were indistinguishable by pulsed-field gel electrophoresis (PFGE). However, the oysters contained other potentially pathogenic V. parahaemolyticusstrains exhibiting different PFGE patterns.

Oyster-Vancouver, B.C.- 07/05/07- Joe Fortes Oyster Specialist Oyster Bob Skinner samples a Fanny Bay oyster at the restuarant. Vancouver Coastal Health now requires restaurants to inform their patrons of the dangers of eating raw shellfish.  (Richard Lam/Vancouver Sun)   [PNG Merlin Archive]

In order to assess the identity, genetic makeup, relatedness, and potential pathogenicity of the V. parahaemolyticusstrains, we sequenced 11 such strains (2 clinical strains and 9 oyster strains). We analyzed these genomes by in silico multilocus sequence typing (MLST) and determined their phylogeny using a whole-genome MLST (wgMLST) analysis. Ourin silico MLST analysis identified six different sequence types (STs) (ST8, ST676, ST810, ST811, ST34, and ST768), with both of the clinical and four of the oyster strains being identified as belonging to ST8.

Using wgMLST, we showed that the ST8 strains from clinical and oyster samples were nearly indistinguishable and belonged to the same outbreak, confirming that local oysters were the source of the infections. The remaining oyster strains were genetically diverse, differing in >3,000 loci from the Maryland ST8 strains. eBURST analysis comparing these strains with strains of other STs available at the V. parahaemolyticus MLST website showed that the Maryland ST8 strains belonged to a clonal complex endemic to Asia. This indicates that the ST8 isolates from clinical and oyster sources were likely not endemic to Maryland. Finally, this study demonstrates the utility of whole-genome sequencing (WGS) and associated analyses for source-tracking investigations.

A nonautochthonous U.S. strain of Vibrio parahaemolyticus isolated from Chesapeake Bay oysters caused the outbreak in Maryland in 2010

Appl. Environ. Microbiol. June 2016 vol. 82 no. 11 3208-3216

Julie Haendiges, Jessica Jones, Robert A. Myers, Clifford S. Mitchell, Erin Butler, Magaly Toro and Narjol Gonzalez-Escalona

http://aem.asm.org/content/82/11/3208.abstract?etoc

Vibrio, from raw oysters, and cirrhosis aren’t a good combination

Vibrio is one of the nastier foodborne pathogens, one of the reasons why I don’t go near raw oysters (the other being that I just don’t like them).

It’s particularly a problem with folks with existing liver problems.

Nazir and colleagues provide an example in the British Medical Journal.

Oyster-Vancouver, B.C.- 07/05/07- Joe Fortes Oyster Specialist Oyster Bob Skinner samples a Fanny Bay oyster at the restuarant. Vancouver Coastal Health now requires restaurants to inform their patrons of the dangers of eating raw shellfish. (Richard Lam/Vancouver Sun) [PNG Merlin Archive]

We present a case of a 40-year-old man with decompensated alcoholic liver cirrhosis presenting with atraumatic cellulitis of one extremity and severe sepsis that rapidly progressed to compartment syndrome despite broad-spectrum antibiotics. Local cultures following debridement revealed Vibrio vulnificus, and subsequent history revealed consumption of raw oysters 48 h before presentation. Our case points out the unique susceptibility of those with cirrhosis and elevated iron saturation to Vibrio septicaemia, as well as the rapidity and severity of the disease progression.

Fancy food ain’t safe food, Hong Kong edition: 6 sick with noro from raw oysters

The Excelsior has taken oysters off the menu due to several diners falling sick at the luxury hotel’s rooftop restaurant last week.

The Centre for Food Safety is investigating after at least six diners who ate imported Penn Cove oysters at the Causeway Bay hotel’s Tott’s and Roof Terrace restaurant on February 23 showed symptoms of food poisoning.

The CFS has also banned the import and sale of raw oysters from the same area.

A spokesman said the CFS had linked a case of food poisoning to the consumption of raw oysters.

“The stool specimen of one of the affected persons tested positive for norovirus upon laboratory testing,” the statement said.

“For the sake of prudence, the CFS has immediately banned the import into and sale within Hong Kong of all raw oysters harvested from the area,” it added.

The ban will affect Tott’s and Roof Terrace and one other restaurant that obtained the same rogue oysters. According to food safety inspectors, no remaining stock from the affected batch was found on their premises.

A spokeswoman for the Excelsior said: “As soon as we knew of these cases, we stopped all the supply of oysters throughout the hotel.

“We will ensure we maintain our due diligence and, keeping the high standards of our food supplies, maintain very high hygiene standards. We’ll continue to select the best possible suppliers.”

Uh-huh.

17 sick: Norovirus linked to Oregon oysters

I don’t eat raw oysters.

State and local public health officials are investigating an outbreak of norovirus that sickened 17 people who ate oysters from Yaquina Bay earlier this month.

Raw oystersAll 17 people, who were among three separate groups totaling 32 people who ate at restaurants throughout Lincoln County, have recovered. One person had been hospitalized. Those who fell ill reported having eaten the oysters between Feb. 12 and Feb. 14.

The Oregon Health Authority Public Health Division, Lincoln County Health & Human Services and the Oregon Department of Agriculture, teamed up on the investigation.

Oregon Oyster Farms Inc., of Newport says it sold the oysters to restaurants and retail stores in Oregon, to wholesalers in New York and Massachusetts, and at its on-site store. The company has issued a voluntary recall of raw, ready-to-eat shucked oysters sold in half-gallons, one-pint plastic tubs and 10-ounce plastic jars, with sell-by dates of Feb. 19 through March 8. It also is recalling product sold in mesh bags containing five dozen in-shell oysters with harvest dates of Feb. 5 through Feb. 15.

Consumers who have purchased those products from Oregon Oyster Farms Inc., are urged to discard them or return them to the place of purchase for a full refund. Consumers with questions may contact the company at 541-265-5078.

Public health officials are working with the Oregon Department of Agriculture to determine the exact source of the contamination, including investigating whether the contamination was more likely to have occurred in the oyster beds or at some point after harvesting, said Emilio DeBess, DVM, state public health veterinarian with the Public Health Division’s Acute and Communicable Disease Prevention Section.

One unopened jug of oysters collected from a restaurant tested positive for the same strain of norovirus found in stool samples from three ill persons.

DeBess said that although consuming raw oysters is popular, there is a risk involved.