Jabarkan Asal usul dari Wabak E.coli O104:H4 2011 dalam bahasa melayu

On May 26, 2011, German officials stated the contaminated vegetables were organic cucumbers that originated in Spain, but European Union spokesperson on 30 May said that two Spanish greenhouses, that were suspected to be sources, had been closed and were being investigated.  The investigation included analyzing soil and water samples from the greenhouses in question, located in the Andalusia region, with results expected by 1 June. Cucumber samples from the Andalusian greenhouses did not show E. coli contamination, but a cross-contamination during transport in Germany or distribution in Hamburg are not discarded.

On May 31, an EU official said that the transport chain was so long that the cucumbers from Spain could have been contaminated at any point that occurred along the transit route.Spanish officials, said before that there was no proof that the outbreak originated in Spain; Spanish Secretary of State for European Affairs Diego Garrido said that "you can't attribute the origin of this sickness to Spain.".

On Tuesday 31 May, lab tests showed that two of the four cucumbers examined did contain toxin-producing E. coli strains, but not the O104 strain that was found in patients; this means that Spanish cucumbers are not the source of the outbreak and German authorities have to start all over again in their search for the source. The bacteria in the other two cucumbers have not yet been identified. No other possibilities have been officially proposed.  Paul Hunter, professor of health protection at the University of East Anglia located in Norwich, United Kingdom, pointed out that salads are a regular cause of outbreaks of food borne diseases including STEC, like this one, and Salmonella.  As of the first of June, the source is still unknown.

Genomic sequencing by BGI Shenzhen revealed that the bacteria belong to a "new super-toxic strain", a hybrid that has acquired some virulence abilities of enteroaggregative E. coli (EAEC) strains by horizontal gene transfer.