Speedy tweets matter for science, and fimbriae hairs matter for death and disease from lethal German EHEC E. coli germs

posted in: Syndicated | 3

…[The German outbreak  bacteria form fimbriae [pili].” Fimbriae are small tentacles that help EAEC bacteria stick to the intestinal wall. This could lead to a stronger colonization of the gut and more toxin being released into the body.

Speed matters: Scientists Rush to Study Genome of Lethal E. coli

…an armada of scientists around the world who are analyzing available genomic data on the  fly and, via tweets, wikis, and blogs, disseminating results online. “I am really surprised and impressed at how fast this is developing,” says Holger Rohde, a microbiologist at the University Medical Center Hamburg-Eppendorf. “I think it shows how relevant this platform can be to science.
The picture emerging from these first analyses is surprising:


The German strain’s DNA sequence revealed the microbe not to be a typical EHEC bacterium. Instead, the pathogen shares 93% of its sequence with EAEC 55989, an E. coli strain isolated in 2002 from an HIV-positive patient in the Central African Republic suffering from chronic diar rhea. EAEC stands for enteroaggregative E. coli, which can form biofilms and are better at colonizing the human gut than EHEC, says Lothar Beutin, head of the National Reference Laboratory for E. coli at the Federal Institute for Risk Assessment in Berlin. They usually do not carry the gene for the Shiga toxin, however. “The sequence really looks like a typical EAEC that has acquired the Shiga toxin gene,” Beutin says.

…some of the unusual characteristics of the German outbreak: the high number of HUS cases, for example, and the fact that so many young, healthy adults are becoming sick. “At first, we thought that the severity of the cases might be due to some change in the toxin,” Rohde says. “But now it seems more likely that is just the fact  that these bacteria form fimbriae [pili].” Fimbriae are small tentacles that help EAEC bacteria stick to the intestinal wall. This could lead to a stronger colonization of the gut and more toxin being released into the body, Rohde and other scientists suggest.

From
 www.sciencemag.org   
SCIENCE    VOL 332    10 JUNE 2011  p124

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David Tribe is an applied geneticist, teaching graduate/undergrad courses in food science, food safety, biotechnology and microbiology at the University of Melbourne.