Enteropathogenic E. coli Infection Mechanism

Part 3: Intestinal cell forms pedestal
for bacterium, and infection follows

webpart3.mov
source: Howard Hughes Medical Institute (www.hhmi.org/biointeractive.index.html)

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Credits:
Director: Dennis Liu, Ph.D.
Scientific Direction: B. Brett Finlay, Ph.D.
Scientific Content: Satoshi Amagai, Ph.D.
Animators: Eric Keller, Satoshi Amagai, Ph.D.

The bacterium is now firmly bound to the intestinal cell surface via the interaction between the Tir and intimin proteins. Pedestal formation, a very active and striking process, begins. Another intestinal cytoskeletal protein (orange booties) binds to a portion of the bacterial Tir protein that is inside the cell. Once these proteins bind, long strands of actin (yellow balls) start to form. The actin filaments build up directly beneath where the bacterium is bound to the intestinal cell. As the actin filaments lengthen, they push the cell membrane upward, and the bacterium becomes perched atop a dramatic pedestal formed by the intestinal cell.

Once many enteropathogenic bacteria have adhered to the intestinal lining, symptoms of the infection (diarrhea) commence.

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