News / Europe

    E coli: Good Bacteria Gone Bad

    Outbreak in Europe focuses attention on deadly strain

    Samples are taken from a cucumber for a molecular biological test in Brno, Czech Republic on Wednesday, June 1, 2011.
    Samples are taken from a cucumber for a molecular biological test in Brno, Czech Republic on Wednesday, June 1, 2011.

    Multimedia

    Audio

    As a major outbreak of a highly toxic strain of E. coli bacteria continues to sicken residents of Europe, medical experts are racing to find the source.

    E. coli has become a growing public health problem in recent years. The bacteria doesn't usually cause any trouble, says University of Minnesota microbiology professor Michael Sadowski. "E. coli is a normal inhabitant of the intestinal tract of warm-blooded animals."

    That means you, me, our livestock and even wild animals are all carrying strains of E. coli around in our guts. The types that cause disease are rare, Sadowski says.

    "The majority of E. coli are in fact considered to be harmless. And they carry out various biochemical processes in your intestine and they help you digest food."

    E. coli and how it is transmitted

    E. coli is an abbreviation for Escherichia, which is a large and diverse group of bacteria. Most strains are harmless, others can cause illness. Symptoms include stomach cramps, diarrhea and vomiting. The major source is cattle, but other animals, foods and liquids may spread contamination to people.

    • Shiga toxin-producing E. coli

      This is a dangerous form of E. coli known by the acronym STEC. The best known strain of this STEC (also called 0157) was identified in 1982. Transmission and symptoms are similar to the most common form of E. coli.

    • EHEC

      A very serious infection is enterohaemorrhagic E. coli known by the acronym EHEC. It produces toxins, known as verotoxins or Shiga-like toxins. It may lead to life threatening diseases such as hemolytic uremic syndrome, or HUS.

    • HUS

      Scientists believe this is responsible for the European outbreak, originating from a potentially life threatening strain of STEC (0104). HUS afflicts the kidneys, blood and central nervous system.

    And the majority have remained relatively harmless until fairly recently, says University of Minnesota food safety professor Francisco Diez. "We didn't have this type of organism before 1982."

    That's when the first deadly strain of E. coli appeared in hamburger meat in the United States. Before then, Diez says, E. coli wasn't even considered a disease-causing germ.

    According to Diez, it is not clear exactly how this new virulence developed. It may have been changes in the bacteria, or changes in the way food is produced or distributed. Whatever the cause, E. coli is now turning up in a growing number of fruits and vegetables including apples, lettuce, and spinach.

    For a germ that was first found in meat, it seems like a long way to the produce aisle. But Diez says there is a connection.


    "We've seen an increase in cases of produce-associated outbreaks, but ultimately the source is cattle."

    He says cattle-manure fertilizer that has not been well composted may still carry live bacteria from the animals’ gut. Or manure may contaminate irrigation water. It could also be on the hands of someone picking or sorting the produce. Add storage, transportation, and preparation as other places between the farm and the fork where food can become contaminated with the bacteria.

    That's part of why tracing an outbreak to its source is so difficult. In Europe, officials originally blamed Spanish-grown cucumbers, but now they are not so sure. Other suspects include tomatoes and lettuce.

    The problem is, those are all common salad ingredients.

    "It's hard to find enough people that only ate one, and only ate one once in the time period before their infection," says Christopher Braden, head of the foodborne disease section at the U.S. Centers for Disease Control and Prevention." They're commonly eaten. They're commonly eaten together. So to try to tease one apart as to which one is the culprit can be difficult."

    Spain maintains that its cucumbers have been falsely accused. Spanish farmers are losing huge amounts of money, and they are furious.

    The CDC was in a similar position in 2008 when it blamed tomatoes for a salmonella outbreak that ultimately was pinned on peppers.

    Braden says it can be a hard decision to make when you have preliminary information that points to a suspect. "And in the meantime, people are getting ill and possibly dying in large numbers. Sometimes there's a real balancing act between being fast and being right. Often times it's really hard to do both."

    He adds that, if their first suspicions proved correct, they could also be criticized if they did not act.

    There are still a lot of unknowns about the current European outbreak, and it will likely be some time before they are all resolved.

    In the meantime, the advice remains the same: wash your hands after using the toilet, and before preparing food and eating, and wash counters and utensils that come in contact with raw meat.

    And if you are concerned about the cleanliness of raw vegetables, cook them well.


    Steve Baragona

    Steve Baragona is an award-winning multimedia journalist covering science, environment and health.

    He spent eight years in molecular biology and infectious disease research before deciding that writing about science was more fun than doing it. He graduated from the University of North Carolina at Chapel Hill with a master’s degree in journalism in 2002.

    You May Like

    Rolling Thunder Tribute to US Military Turns into a Trump Rally

    Half-million motorcycles are expected to rumble Sunday afternoon from Pentagon to Vietnam War Memorial for rally in event group calls Ride for Freedom

    The Struggle With Painkillers: Treating Pain Without Feeding Addiction

    'Wonder drug' pain medications have turned out to be major problem: not only do they run high risk of addicting the user, but they can actually make patients' chronic pain worse, US CDC says

    Video Canine Reading Buddies Help Students With Literacy

    Idea behind reading program is that sharing book with nonjudgmental companion boosts students' confidence and helps instill love of reading

    This forum has been closed.
    Comments
         
    There are no comments in this forum. Be first and add one

    Featured Videos

    Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
    Chinese-Americans Heart Trump, Bucking National Trendi
    X
    May 27, 2016 5:57 AM
    A new study conducted by three Asian-American organizations shows there are three times as many Democrats as there are Republicans among Asian-American voters, and they favor Hillary Clinton over Donald Trump. But one group, called Chinese-Americans For Trump, is going against the tide and strongly supports the business tycoon. VOA’s Elizabeth Lee caught up with them at a Trump rally and reports from Anaheim, California.
    Video

    Video Chinese-Americans Heart Trump, Bucking National Trend

    A new study conducted by three Asian-American organizations shows there are three times as many Democrats as there are Republicans among Asian-American voters, and they favor Hillary Clinton over Donald Trump. But one group, called Chinese-Americans For Trump, is going against the tide and strongly supports the business tycoon. VOA’s Elizabeth Lee caught up with them at a Trump rally and reports from Anaheim, California.
    Video

    Video Reactions to Trump's Success Polarized Abroad

    What seemed impossible less than a year ago is now almost a certainty. New York real estate mogul Donald Trump has won the number of delegates needed to secure the Republican presidential nomination. The prospect has sparked as much controversy abroad as it has in the United States. Zlatica Hoke has more.
    Video

    Video Drawings by Children in Hiroshima Show Hope and Peace

    On Friday, President Barack Obama will visit Hiroshima, Japan, the first American president to do so while in office. In August 1945, the United States dropped an atomic bomb on the city to force Japan's surrender in World War II. Although their city lay in ruins, some Hiroshima schoolchildren drew pictures of hope and peace. The former students and their drawings are now part of a documentary called “Pictures from a Hiroshima Schoolyard.” VOA's Deborah Block has the story.
    Video

    Video Vietnamese Rapper Performs for Obama

    A prominent young Vietnamese artist told President Obama said she faced roadblocks as a woman rapper, and asked the president about government support for the arts. He asked her to rap, and he even offered to provide a base beat for her. Watch what happened.
    Video

    Video Roots Run Deep for Tunisia's Dwindling Jewish Community

    This week, hundreds of Jewish pilgrims are defying terrorist threats to celebrate an ancient religious festival on the Tunisian island of Djerba. The festivities cast a spotlight on North Africa's once-vibrant Jewish population that has all but died out in recent decades. Despite rising threats of militant Islam and the country's battered economy, one of the Arab world's last Jewish communities is staying put and nurturing a new generation. VOA’s Lisa Bryant reports.
    Video

    Video Meet Your New Co-Worker: The Robot

    Increasing numbers of robots are joining the workforce, as companies scale back and more processes become automated. The latest robots are flexible and collaborative, built to work alongside humans as opposed to replacing them. VOA’s Tina Trinh looks at the next generation of automated employees helping out their human colleagues.
    Video

    Video Wheelchair Technology in Tune With Times

    Technologies for the disabled, including wheelchair technology, are advancing just as quickly as everything else in the digital age. Two new advances in wheelchairs offer improved control and a more comfortable fit. VOA's George Putic reports.
    Video

    Video Baby Boxes Offer Safe Haven for Unwanted Children

    No one knows exactly how many babies are abandoned worldwide each year. The statistic is a difficult one to determine because it is illegal in most places. Therefore unwanted babies are often hidden and left to die. But as Erika Celeste reports from Woodburn, Indiana, a new program hopes to make surrendering infants safer for everyone.
    Video

    Video California Celebration Showcases Local Wines, Balloons

    Communities in the U.S. often hold festivals to show what makes them special. In California, for example, farmers near Fresno celebrate their figs and those around Gilmore showcase their garlic. Mike O'Sullivan reports that the wine-producing region of Temecula offers local vintages in an annual festival where rides on hot-air balloons add to the excitement.
    Video

    Video US Elementary School Offers Living Science Lessons

    Zero is not a good score on a test at school. But Discovery Elementary is proud of its “net zero” rating. Net zero describes a building in which the amount of energy provided by on-site renewable sources equals the amount of energy the building uses. As Faiza Elmasry tells us, the innovative features in the building turn the school into a teaching tool, where kids can't help but learn about science and sustainability. Faith Lapidus narrates.

    Special Report

    Adrift The Invisible African Diaspora