As soon as the foodborne pathogen Vibrio parahaemolyticus infects a human intestinal cell, the bacteria are already planning their escape. After all, once it is in and multiplies, the bacterium must find a way out to infect new cells.
Now, UT Southwestern scientists have discovered the surprising route that V. parahaemolyticus takes during this exit — or egress — from cells. The bacteria, they report in the journal eLife, gradually modify cholesterol found in a cell’s plasma membrane, eventually weakening the membrane enough so that it can break through.
“The more we understand how bacteria are manipulating host cells at a molecular level, the more we understand how they cause disease,” says study leader Kim Orth, Ph.D., professor of molecular biology and biochemistry at UTSW and a Howard Hughes Medical Institute investigator. “Bacteria have many different mechanisms to escape, but this stood out because it’s an especially novel one.”

