Suicide bacteria made to fight infections

Scientists have genetically engineered a common bacteria found in the body in a way to target and destroy a potentially drug resistance harmful microbe. Researchers at Nanyang Technological University in Singapore developed a strain of harmless E. coli (Escherichia coli) bacteria that are able to detect and kill Pseudomonas aeruginosa, which is a leading cause of hospital acquired infections. P.aeurginosa is an opportunistic bacteria that lives in soil, water, and even in environments like hot tubs. For most healthy people, this bacteria seldom poses a problem but in patients with a weak immune system it may cause fatal infections that are resistant to a many powerful antibiotics. E. coli strains produce a protein called LasR, which recognizes molecules that P.aeurginosa bacteria use to communicate with one another. When LasR detects to these chemical signals, it switches on two genes. The first gene creates a toxin called pyocin that is lethal to P.aeeruginosa while the other gene orders the E. coli to break apart, which causes the release of more pyocin molecules, said lead researchers Nazanin Saeidi and Choon Kit Wong. Pyocin toxin is actually made and used by P.aeruginosa itself to kill other Pseudomonas competing strains. However, the scientists engineered the suicide E. coli to produce a form of pyocin called S5 that kill off the strains of P.aeruginosa responsible for most of the hospital infections. The suicide E.coli showed successful results in lab trials and managed to destroy 99 percent of targeted P.aeruginosa and even 90 percent of the drug resistant forms, the scientists reported in the journal Molecular Systems Biology. However, it may takes some years of developments and safety studies before using the new lethal weapon in animal and human trials. The scientists hope that the new proceeding may lead some day to new effective treatments for infections that are highly resistant to antibiotics.