Beating Bugs with Bugs

A major problem for hospitals these days are infections caused by a super-bug known as MRSA, - a strain of bacteria that have become resistent to all but a few antibiotics. But now, thanks to James Burnie and his team at the University of Manchester, doctors have a new weapon up their sleeves in the form of a new drug that mimics the bodies' own antibodies. The scientists took blood samples from people who had survived infections with the MRSA super-bug and isolated an antibody that they had produced against the bacterium. (The antibody binds to a protein called the ABC transporter which controls the movement of proteins and ions in and out of bacterial cells). Antibodies are made in immune cells by cleverly rearranging short pieces of DNA. The researchers used the MRSA antibodies from the patients to work out the DNA sequence coding for these antibodies, and inserted this piece of DNA into E. coli bacteria. When these genetically-modified bacteria grow they produce large amounts of the antibody which can then be harvested, purified and given to patients. In laboratory tests the new drug, called Aurograb, greatly reduced the growth of the MRSA super-bug, and trials are now underway on patients in UK hospitals. The greatest challenge facing this new idea is whether the super-bugs can change to become resistent to this new drug too. It's ironic that scientists are using bugs to produce substances to kill other bugs !