On the 20th of January Dr Chris Morris from the University of East Anglia delivered a talk to a keen audience of WGS Biologists and general science enthusiasts alike.
Dr Morris explained the ingenious method which he hopes will eventually lead to a new breed of antibiotics. Antibiotics in circulation today use a variety of methods to kill the bacterial cell causing infection – prevent the construction of the cell wall of the bacteria, stopping protein synthesis, prevent the bacteria multiplying, or allow the host’s defence mechanism to deal with it. The new method proposed by Dr Morris and his team was simple in concept, but as he later explained was much more complex in practise.
Segments of sense (coding strand) DNA are surrounded by a capsule of nanoparticles measuring between 1 and 100 nanometers in size. This capsule locates the bacteria being targeted by electrostatic forces of attractions and locks onto the bacteria cell surface. When attached, it punches a hole and the sense DNA fragment is released into the cell. Once inside the cell, the DNA segment knocks out a transcription factor – a protein that binds to specific DNA sequences, thereby controlling the rate of transcription of genetic information from DNA to messenger RNA – resulting in the repair response gene being switched off. The repair response to the hole formed in the surface of the bacterial cell no longer occurs, and thus by lysis the cell is destroyed. I believe it’s fair to say the audience were stunned by Dr Morris’ astounding method of puncturing the cell, and preventing the repair response as a way to remove bacterial infections.
Dr Morris also detailed some of the remaining hurdles to be overcome. One problem that continues is the control of the size of the nano particles and prevent the coagulation of them. Dr Morris is hopeful with more years of testing and hard work this form of antibiotic may one day be prescribed to patients fighting bacterial infections. His team’s method also raises the obvious question, is there any way we could apply this to the fight against viral infections?