E coli strain previously unseen and 'resistant to antibiotics'

Bacterial outbreak had spread beyond Germany to 10 countries with people infected through eating contaminated vegetables
Alok Jha guardian.co.uk 2 Jun 11;

A strain of E coli spreading across Europe is a previously unseen and more virulent variant of the bacterium, health officials have said.

So far 18 people have died and more than 2,000 havehad become infected from eating contaminated vegetables. The bacterial outbreak had spread beyond Germany to 10 countries.

After scientists sequenced the genetic code of the E coli, Hilde Kruse, a food safety expert at the World Health Organisation told Associated Press: "This is a unique strain that has never been isolated from patients before … [there are] various characteristics that make it more virulent and toxin producing."

Scientists also said that the new strain appeared likely to be resistant to common antibiotics.

A spokesperson for the UK's Health Protection Agency said the organisation had not sequenced the bacterium but had agreed with the WHO finding that the E coli O104 strain associated with the outbreak "which we know to have a highly unusual combination of virulent properties, could be one that has never been seen before".

There is no evidence yet that the bacteria have appeared on British vegetables.

Stephen Smith, a clinical microbiologist at Trinity College, Dublin, said the new E coli strain was a "mongrel" combining two "nasty" types of the bacterium. He said: "It is very similar to enteroaggregative E coli which has been associated with outbreaks of watery diarrhoea, in developing nations since 1970. However, this bacterium has been recognised as a cause of diarrhoea in industrialised nations and has caused outbreaks in the US, Sweden, Britain and Germany."

The toxin produced by the bacterium binds to, and damages, kidney cells and leads to haemolytic uraemic syndrome (HUS), a rare and severe complication that destroys red blood cells and can affect the central nervous system. More than 500 cases of HUS have been reported in Germany and three cases were found in the UK in people who had recently been to Germany.

An HPA spokesperson said: "Bacteria and viruses are evolving all the time. We expect to see new strains, sometimes more virulent or resistant to antibiotics than others, and plan on that basis."

FACTBOX-Facts about Europe's E. coli outbreak
Reuters 2 Jun 11;

June 2 (Reuters) - The deadly strain of E. coli that has killed at least 17 people in Europe and sickened 1,500 has never been seen in a human population and it may be the most toxic yet, health experts said on Thursday.

Here are answers to some frequently asked questions about the outbreak.

1. What is E. coli? Escherichia coli (E. coli) are a group of bacteria that live in the intestines of many animals, including humans. Most strains are harmless, but others can cause illness ranging from diarrhea to pneumonia. E. coli infections can be mild to life-threatening.

2. How is E. coli spread? E. coli infections are caused by ingesting the feces of infected animals or humans, often via contaminated food or water. People can contaminate food by failing to wash their hands after using the toilet or changing a baby's diaper, although person-to-person infection is rare. Feces from animals, ranging from cows to birds, can contaminate water or crops.

3. What is the strain? The strain that is sickening people in Germany and other parts of Europe, known as 0104:H4, is part of a class of bacteria known as Shiga toxin-producing Escherichia coli, or STEC. It is the first time the strain has caused an outbreak in humans. Symptoms of STEC infections vary for each person but often include severe stomach cramps, diarrhea (often bloody) and vomiting. Low fever (less than 101 degrees F/38.5 degrees C) also may be present. Most people recover within five to seven days.

4. What are the major complications of this strain? Hundreds of people sickened in the outbreak have developed hemolytic uremic syndrome, or HUS, a life-threatening complication of E. coli infections. The syndrome, which results in the destruction of red blood cells and severe kidney problems, usually arises about a week after diarrhea starts.

Symptoms of HUS include decreased frequency of urination, extreme fatigue and the loss of the skin's pink color. Children, the elderly and people with compromised immune systems usually are at highest risk for HUS. In the case of this outbreak, healthy adult women have been hard hit.

5. What is the medical treatment? Experts said supportive therapy, including hydration, is important. Treatment for HUS includes dialysis for kidney failure and blood transfusions for anemia. Antibiotics should not be used, as there is no evidence that treatment with antibiotics is helpful. Antibiotics and antidiarrheal agents like Imodium also may increase risk of HUS.

Source: U.S. Centers for Disease Control and Prevention (Reporting by Lisa Baertlein in Los Angeles and Julie Steenhuysen in Chicago; Editing by Peter Cooney)