The German authorities said on Monday that Germany's first sample tests of the allegedly contaminated bean sprouts have found no E. coli strains that have sickened more than 2,000 people in Europe.
According to a statement issued by the Agriculture Ministry of the Lower-Saxony state, 23 of 40 samples concerning the suspected sprouts from a market garden in the state have tested negative, and further tests are still pending.
"Based on the initial findings in tests of some of the samples, especially the seeds, we assume that intensive analytical efforts are needed to prove that the suspected pathogen is really there," the statement said.
Lower-Saxony's Agriculture Minister Gert Lindemann said Sunday that a market garden in the rural district of Uelzen had provided a connection "involving all the main outbreaks" of the disease.
Restaurants and food outlets of almost all E. coli-affected areas had received shipments of sprouts directly or indirectly from the company, state officials said.
The German authorities have been racing to track down the source of the pathogen since the outbreak, which has infected people in 12 countries, all of whom had once travelled in northern Germany.
More than 600 of those infected have developed Hemolytic Uremic Syndrome, a potentially deadly complication attacking the kidneys.
The E. coli source was first thought to be cucumbers from Spain, which has caused huge loses for Spain farmers. However, this conclusion was overthrown by laboratory tests in Hamburg later.