Loosen Up
Bacterial toxin may lead to less painful treatments for diabetes and brain cancer
By John Travis
Take the nasty bacterium that causes cholera, delete the gene for its well-studied toxin, and you should end up with a harmless microbe that can immunize people against the real thing. It sounded like a good plan, recalls Alessio Fasano of the University of Maryland School of Medicine in Baltimore.
The scheme failed, however. A decade ago, when Fasano and his colleagues used a genetically stripped Vibrio cholerae to vaccinate 10 people, half the volunteers developed mild diarrhea. The altered bacterium obviously had some bite left in it.