. Author manuscript; available in PMC: 2019 Jul 1.
Published in final edited form as: Nat Microbiol. 2019 Feb 18;4(5):837–845. doi: 10.1038/s41564-019-0369-x
Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:http://www.nature.com/authors/editorial_policies/license.html#terms