An employee of the veterinarian institute in Hanover, central Germany, prepares a quick test for the identification within hours of the pathogenic agent in the virulent E. coli bacteria (EHEC) on June 1, 2011. The number of people sickened by a mysterious killer bacteria grew, two weeks after the outbreak in Germany, while fears over tainted vegetables hit European farmers hard. Scientists and health officials say they have identified the E. coli bacteria (EHEC) responsible for the outbreak, which has mainly affected northern Germany, but are unable to say what caused it or who was responsible. AFP PHOTO CAROLINE SEIDEL GERMANY OUT