Context

The first widely-prescribed antibiotic was Penicillin, mass-produced from 1943. Since then antibiotics have continued to save millions of lives across the world. However, in 1947 the first cases of antibiotic-resistant bacteria were found in the clinic. This has been the general pattern every time a new antibiotic has come onto the market - it is only a matter of a few years or less before some bacteria become resistant.

Bacteria are smaller and simpler than human cells and they can divide very quickly, in some cases they can double in number in just 20 minutes. Every time a bacterium divides, random mistakes are made when it copies its DNA code. These changes can result in the new bacterium having a slightly different structure. On some occasions, it is the target of the antibiotic which is changed and hence the antibiotic cannot bind to and kill the bacterium. So when the antibiotic is given to the person, all the normal bacteria die but these new mutant bacteria are now resistant and continue to grow and divide. Hence an antibiotic-resistant strain of bacteria has been created. It is by this process that bacteria such as MRSA (Methicillin Resistant Staphylococcus Aureus) are created.

It is possible to slow down the process of antibiotic resistance by prescribing antibiotics as sparingly as possible and by having every patient complete full courses of antibiotics rather than stop part-way through. But if we are to continue winning the fight against bacteria, scientists must design and develop new types of antibiotic which avoid all the current methods of resistance. There has been only one major new type of antibiotic released in the last 25 years and so there is a strong need for research into this important area.

Current Work

My research is focused on developing compounds which we can make cheaply in the laboratory that bind to the DNA of bacteria. They bind to DNA causing it to bend in on itself and tangle up like a ball of wool. This tangled DNA is now of no use to the bacteria as it cannot unravel it, which it needs to if it's going divide and make new bacteria. I am developing ways of targeting these molecules precisely to the DNA of bacteria and better understanding how they could possibly operate in the clinic.

A typical day in the laboratory

 

The World Health Organisation monitors the use of antibiotics worldwide