E.coli or Escherichia coli are bacteria that normally live in the intestines of humans and animals. Although, most strains of these bacteria are harmless, several are known to produce toxins that can cause diarrhea. One particular E.coli strain called 0157 can cause severe diarrhea and kidney damage.almonella. Salmonella is the second most common cause of food poisoning after campylobacter. It has been found in unpasteurised milk, eggs and raw egg products, meat and poultry. It can survive if food is not cooked properly.