Experimental evolution and bacterial resistance: (co)evolutionary costs and trade-offs as opportunities in phage therapy research.

Antagonistic coevolution between bacteria and phages (reciprocal selection for resistance and infectivity) has been demonstrated in a wide range of natural ecosystems, as well as experimental populations of microbes, yet exploiting knowledge of coevolution for the prophylactic and therapeutic use of phages is under-explored. In this addendum to our recent paper we discuss how real-time coevolution studies using experimental populations of bacteria and phages can provide novel insight into the changes in bacterial phenotypes that result from resistance evolution against coevolving phages, and how this may ultimately improve our understanding of phage therapy and ability to design effective treatments.