An Austrian scientist holds a petri dish with bacterial strains of EHEC bacteria (enterohaemorrhagic Escherichia coli.) in the microbiological laboratory of the The Austrian Agency for Health and Food Safety (AGES) in Vienna June 9 , 2011. The German government has been criticised at home and around Europe for failing so far to pin down the cause of the E.coli outbreak that has killed 27 and stricken more than 2,700 people in 12 countries. All cases have been traced back to near Hamburg in northern Germany. REUTERS/Leonhard Foeger (AUSTRIA - Tags: SCI TECH HEALTH)