[BabbyAnn]

Could the problem be due to imported food?
We are used to bacteria which we meet around us every day, but may not have been into contact with imported bacteria before and hence have not built up immunity to them.

A bacterial cell such as E.coli can multiply within 20 minutes in ideal growing conditions - the gut is the perfect place (37oC and nutrients) and some bacteria can also readily exchange DNA with other types of bacteria or phages (these are like viruses that infect bacteria) - so new strains of bacteria (eg different types of E.coli) can emerge readily with a rapid growth in cell numbers.  This is a natural course of "evolution" and nothing sinister about it.  It is one of the reasons why bacteria are one of the most studied forms of life because of the genetic diversity and rapid growth and scientists can use them to learn about genomes and make medicines.

The immune response is a bit more complicated - because there are so many types and strains of E.coli, we don't all have the same antibody response, even a population within the same country.  It would be nice to think the outbreak was the result of imported food but there are many sources of contamination.

In this case, the E.coli strain was found in highest numbers from a different animal species (bovine) so the most likely source of contamination is from vegetables grown in cow manure and poor hygiene to wash the food and hands after handling. 

Severe illness (or even death) is not down to the bacteria itself but the toxins (natural by products) they produce and this can cause serious diarrhoea and dehydration as the body tries to get rid of it from the body as quickly as possible.  This can also lead to kidney failure in extreme cases as fluids are pumped from the blood system into the gut to facilitate rapid expulsion to get rid of the source of infection.  The effect of the toxin (rather than the bacteria) is the cause of haemolytic uraemic syndrome (the red blood cells are haemolysed/break down)   

With regards to using raw manure versus rotted down, although it is likely most of the bacteria will have died, some will remain viable but just be dormant.  The soil is teaming with microbes most of which are naturally occurring but if food is improperly prepared, these can become pathogens.  A classic case is the Clostridium botulinum which is found in soil but only becomes deadly if preserved food is done incorrectly.

I hope I wasn't too technical  but I just wanted to dispel any myths.  I think the title of this thread should be "now wash your food and hands" to remind people to go back to basics 

[Yorkie]

That's really interesting, thanks for the explanation 

On your last paragraph, are you saying that raw manure is less 'safe' on the bacterial front than well rotted, or that in practice there's little difference in risk?

[BabbyAnn]

On your last paragraph, are you saying that raw manure is less 'safe' on the bacterial front than well rotted, or that in practice there's little difference in risk?

Raw manure would most likely have a higher load of viable gut bacteria than rotted down stuff - but I wouldn't like to use the word "safer" because all around us are bacteria.  It only becomes a problem when hygiene is disregarded and is ingested.  Most root vegetables are only contaminated on the surface (unless you accidentally break that skin and it gets into the flesh) so washing them, peeling and cooking them thoroughly should be fine.

Peas eaten straight from pods should be fine (unless you had just been handling manure and not washed your hands)  Fruit on the other hand - from my experience, birds have a habit of pooping wherever they land, so I'll leave that to your imagination ...

I meant to add earlier about cooking - when food is cooked properly and served piping hot, then bacteria are killed off.  Food that is not cooked thoroughly or is contaminated (such as a ready cooked meal or a salad) and just kept warm on the other hand, are potential sources of food poisoning because bacteria can thrive and also produce toxins which is what usually makes people very ill.