title: Evolution of Staphylococcus aureus by large chromosomal replacements.
abstract: Conjugative transfer and replacement of hundreds of kilobases of a bacterial chromosome can occur in vitro, but replacements in nature are either an order of magnitude smaller or involve the movement of mobile genetic elements. We discovered that two lineages of Staphylococcus aureus, including a pandemic methicillin-resistant lineage, were founded by single chromosomal replacements of at least approximately 244 and approximately 557 kb representing approximately 10 and approximately 20% of the chromosome, respectively, without the obvious involvement of mobile genetic elements. The replacements are unprecedented in natural populations of bacteria because of their large size and unique structure and may have a dramatic impact on bacterial evolution.
authors.affiliation: Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, United Kingdom.
authors.forename: D Ashley
authors.initials: DA
authors.lastname: Robinson
authors.forename: Mark C
authors.initials: MC
authors.lastname: Enright
mesh_terms: D001483:Base Sequence; D005075:Biological Evolution; D002876:Chromosomes, Bacterial / Q000235:genetics*; D003227:Conjugation, Genetic; D016106:Methicillin Resistance / Q000235:genetics; D008969:Molecular Sequence Data; D013211:Staphylococcus aureus / Q000235:genetics*