The E. coli epidemic in Europe is caused by a new, highly infectious and toxic strain of bacteria that carries genes giving it resistance to a few classes of antibiotics, Chinese scientists who analyzed the organism said.
The scientists at the Beijing Genomics Institute, who are collaborating with Germany's University Medical Center Hamburg-Eppendorf, completed sequencing the genome of the bacterium in three days after receiving its DNA samples.
"This E. coli is a new strain of bacteria that is highly infectious and toxic," said the scientists at the Beijing Genomics Institute in Shenzhen city in southern China.
They said in a press release on Thursday the bacterium was closely related to another E. coli strain, called EAEC 55989, which was previously isolated in central Africa and known to cause serious diarrhea.
Authorities are still hunting for the source of the new bacteria, which is believed to have contaminated raw vegetables. The E.coli outbreak has so far killed at least 18 people and made more than 1,500 others ill in eight European countries and in the USA after 3 people returned from Europe with the strain.
University Medical Center Hamburg-Eppendorf, one of the largest hospitals in Hamburg, treated many of the infected patients from north Germany and found they did not respond to some of the antibiotics used, the Chinese scientists said.
"The analysis further showed that this deadly bacterium carries several antibiotic resistant genes, including resistance to aminoglycoside, macrolides and Beta-lactam antibiotics: all of which makes antibiotic treatment extremely difficult," the scientists said.
This new strain of also bore the hallmarks of other E. coli strains that are known to cause symptoms such as bloody diarrhea, or hemorrhagic colitis, and hemolytic-uremic syndrome, which affects the kidneys.
E.coli can be passed from person to person but experts say there was no evidence this was happening in any significant numbers in this outbreak.
Health experts are recommending strict hygiene measures such as hand washing and thorough cleaning and cooking of food.
The sequences of this new E. coli strain have been uploaded to the National Center for Biotechnology Information (SRA No: SRA037315.1) and are also available for download at:
ftp://ftp.genomics.org.cn/pub/Ecoli_TY-2482