The work, which is published this week in Molecular Systems Biology
, is an example of the emerging field of synthetic biology - in which researchers use engineering principles to design novel living systems.
Assistant Professors Chueh Loo Poh and Matthew Wook Chang led the team that designed the new E. coli bacteria. Guided missiles
The weapon used is a substance called pyocin, which is made by some bacteria to kill specific competitors, such as
P. aeruginosa, while leaving E. coli unscathed.
The sensing device harnesses a system that P. aeruginosa uses to detect its own population numbers called 'quorum sensing'. Quorum sensing enables each P. aeruginosa to be aware of the presence of other P. aeruginosa microbes.
"Most microbial species have their own quorum-sensing [system]", says Poh. By putting the P. aeruginosa
quorum-sensing machinery into the E. coli missile the researchers created a detection device which would notice when there were P. aeruginosa nearby.
"When you have an infection and take a drug it kills all the beneficial bacteria too. E. coli isn't normally found in the respiratory system.
E.coli that could detect signs of Pseudomonas aeruginosa, a leading cause of
infection that can be fatal to patients with weak immune systems.
When added to a culture of P. aeruginosa in lab tests, the artificial E.coli
- slimy communities of bacteria which are difficult to destroy - by up to 90
new approach to tackling drug-resistant infections, where progress using
summary, we engineered a novel biological system, which comprises sensing,
killing, and lysing devices, that enables E. coli to sense and eradicate
pathogenic P. aeruginosa strains by exploiting the synthetic biology
P. aeruginosa is a bacteria which infects the lungs and digestive system,
systems.
The strains found in hospitals are often resistant to antibiotics, creating a
The E.coli strain developed by researchers from the Nanyang Technological
P. aeruginosa naturally produces a toxin known as pyocin, but the scientists
detected nearby.
The E.coli bacteria then burst themselves open and cover the P. aeruginosa
bacteria with pyocin, which eats away at the outer cell wall and causes the
In a lab in Singapore, scientists are designing and breeding suicide bombers. Nazanin Saeidi and Choon Kit Wong have found a new way of killing Pseudomonas aeruginosa, an opportunistic species that thrives wherever humans are weak. It commonly infects hospital patients whose immune systems have taken a hit. To seek and destroy this threat, Saiedi and Wong have used the common lab bacterium Escherichia coli as a sacrificial pawn.
Their E.coli recruits produce a protein called LasR, which recognises molecules that P.aeruginosa
It produces pyocin, a toxin that kills
P.aeruginosa innovation. By arming their bombers with pyocin S5, Saeidi and Wong found that they could kill many
P.aeruginosa strains that cause problems for hospital patients.
P.aeruginosa called biofilms. E.coli
bombers levelled them.
Meanwhile, the drug onslaught harms helpful bacteria that normally colonise our bodies.
As an alternative, some scientists have tried using viruses called phages, which target and kill bacteria. Saeidi and Wong have taken a different approach. antimalarial drugs, create biofuels, decontaminate water
and even hunt cancer cells.