Engineered Bacteria Secrete Another Species' Toxin to Kill It

Scientists at Nanyang Technological University in Singapore have successfully engineered Escherichia coli bacteria that attack Pseudomonas aeruginosa, a bacterium that causes lethal infections to humans. P. aeruginosa fights with its own species by releasing toxic proteins known as pyocins. Thus, biochemical engineer Matthew Chang and colleagues inserted into E.coli the genes that code for pyocin 5, which kills specific strains of P. aeruginosa that infect people. E. coli automatically burst only when they have detected chemical signals from infectious strains of P. aeruginosa. With this specific reaction, the development of antibiotic resistance is delayed.

In laboratory tests, only 1 percent of P. aeruginosa have survived in the presence of the engineered E. coli. The researchers are currently improving the engineered E. coli to deliver better pyocin before using animal models. They are also developing another E. coli strain that targets Vibrio cholerae, a bacterium that targets human gut and cause cholera.

Know more at http://www.nature.com/news/2011/110816/full/news.2011.483.html.