@article {Lam098178, author = {Margaret M.C. Lam and Ryan R. Wick and Kelly L. Wyres and Claire Gorrie and Louise M. Judd and Sylvain Brisse and Adam Jenney and Kathryn E. Holt}, title = {Frequent emergence of pathogenic lineages of Klebsiella pneumoniae via mobilisation of yersiniabactin and colibactin}, elocation-id = {098178}, year = {2017}, doi = {10.1101/098178}, publisher = {Cold Spring Harbor Laboratory}, abstract = {Klebsiella pneumoniae (Kp) is a commensal bacterium that causes opportunistic infections. Evidence is mounting that Kp strains carrying acquired siderophores (yersiniabactin, salmochelin and aerobactin) and/or the genotoxin colibactin are highly pathogenic and can cause invasive disease. Here we explored the diversity of the Kp integrative conjugative element (ICEKp), which mobilises the yersiniabactin locus ybt, by comparing 2499 diverse Kp genomes. We identified 17 distinct ybt lineages and 14 ICEKp structural variants (some of which carry colibactin (clb) or salmochelin synthesis loci). Hundreds of ICEKp transmission events were detected affecting hundreds of Kp lineages, including nearly \>20 transfers into the globally-disseminated, carbapenem-resistant clonal group CG258. Additionally, we identify a plasmid-encoded lineage of ybt, representing a new mechanism for ybt dispersal in Kp populations. We introduce a novel sequence-based typing approach for identifying ybt and clb variants, to aid the identification of emerging pathogenic lineages and the convergence of antibiotic resistance and hypervirulence.SIGNIFICANCE Klebsiella pneumoniae infections are increasingly difficult to treat with antibiotics. Some K. pneumoniae carry extra genes that allow them to synthesise yersiniabactin, an iron-scavenging molecule, which enhances their ability to cause disease. These genes are located on a genetic element that can easily transfer between strains. Here, we screened 2499 K. pneumoniae genome sequences and found substantial diversity in the yersiniabactin genes and the associated genetic elements, including a novel mechanism of transfer, and detected hundreds of distinct yersiniabactin acquisition events between K. pneumoniae strains. We also developed tools to identify and type yersiniabactin genes, to help track the evolution and spread of yersiniabactin in global K. pneumoniae populations and to monitor for acquisition of yersiniabactin in antibiotic-resistant strains.}, URL = {https://www.biorxiv.org/content/early/2017/01/04/098178}, eprint = {https://www.biorxiv.org/content/early/2017/01/04/098178.full.pdf}, journal = {bioRxiv} }