An employee holds petri dishes with bacterial strains of EHEC bacteria in the microbiological laboratory...
An employee holds petri dishes with bacterial strains of EHEC bacteria (bacterium Escherichia coli.) in the microbiological laboratory of the 'Universitaetsklinikum Hamburg-Eppendorf ' (University Clinic Eppendorf- UKE) in the northern German town of Hamburg, June 2, 2011. REUTERS/Fabian Bimmer (GERMANY - Tags: HEALTH SCI TECH)