The qualified rate of coli group tested from the equipment, tableware and hands in big, middle and small restaurants was 94.44%, 67.62% and 33.33% respectively.

While most E.coli bacteria are harmless, a group called enterohaemorrhagic E. coli (EHEC) can produce toxins, known as Shiga toxins or verotoxins, which damage blood cells and the kidneys.

A method is found out to determine the total coli-group by the five fermentation tubes.