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.'