title: The emergence of bacterial "hopeful monsters".
abstract: The global spread of antibiotic-resistant bacteria has largely been driven by the dissemination of successful lineages. A particularly important example is sequence type (ST) 258 of Klebsiella pneumoniae, a common cause of health care-associated infections. Representatives of this lineage carry a variable array of plasmid-borne resistance genes, typically including a carbapenemase effective against the full range of clinically important β-lactams. In their recent mBio article, Chen et al. [mBio 5(3):e01355-14] described how ST258 emerged through "hybridization" between two other strains, with a second recombination resulting in the diversification of a key antigen. This commentary describes the findings in the context of other examples where saltational evolution has resulted in the sudden emergence of important pathogenic bacteria.
authors: Department of Infectious Disease Epidemiology, Imperial College London, St. Mary's Campus, London, United Kingdom.
authors: Nicholas J
authors: NJ
authors: Croucher
authors: Bill and Melinda Gates Foundation, Seattle, Washington, USA.
authors: Keith P
authors: KP
authors: Klugman
mesh_terms: D007710:Klebsiella Infections / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000235:genetics* / Q000302:isolation & purification*; D011995:Recombination, Genetic