Scientists identify genetic catalysts that speed up evolution of antibiotic resistance

Researchers at Oxford University have shown that it is possible to identify genetic catalysts that accelerate the evolution of antibiotic resistance in bacteria - and that this knowledge could be used to design treatments to stifle the development of resistance. The study was funded by the Wellcome Trust and the European Research Council and is published in the journal Nature Ecology & Evolution . Senior author Professor Craig MacLean, from Oxford's Department of Zoology, said: 'It is well established that different species of bacteria evolve resistance to antibiotics during infections at very different rates. One potential explanation for this observation is that some species of bacteria may be intrinsically better at evolving resistance to antibiotics than others.' To test this hypothesis, the team challenged species of the genus Pseudomonas - bacteria that are opportunistic pathogens of humans, animals and plants - with the common antibiotic ceftazidime. They found that individual species of Pseudomonas evolved antibiotic resistance at radically different rates. Professor MacLean said: 'We identified that the presence of a gene known as ampR is a major cause of this variation. ampR is a master regulatory gene that switches the expression of hundreds of other genes on and off, including genes involved in antibiotic resistance.