title: Phylogenetic analysis of Staphylococcus aureus CC398 reveals a sub-lineage epidemiologically associated with infections in horses.
abstract: In the early 2000s, a particular MRSA clonal complex (CC398) was found mainly in pigs and pig farmers in Europe. Since then, CC398 has been detected among a wide variety of animal species worldwide. We investigated the population structure of CC398 through mutation discovery at 97 genetic housekeeping loci, which are distributed along the CC398 chromosome within 195 CC398 isolates, collected from various countries and host species, including humans. Most of the isolates in this collection were received from collaborating microbiologists, who had preserved them over years. We discovered 96 bi-allelic polymorphisms, and phylogenetic analyses revealed that an epidemic sub-clone within CC398 (dubbed 'clade (C)') has spread within and between equine hospitals, where it causes nosocomial infections in horses and colonises the personnel. While clade (C) was strongly associated with S. aureus from horses in veterinary-care settings (p = 2 × 10(-7)), it remained extremely rare among S. aureus isolates from human infections.
authors: Robert Koch Institute, Wernigerode, Germany.
authors: Mohamed M H
authors: MM
authors: Abdelbary
authors: Institute of Microbiology and Epizootics, Free University Berlin, Berlin, Germany.
authors: Anne
authors: A
authors: Wittenberg
authors: Robert Koch Institute, Wernigerode, Germany.
authors: Christiane
authors: C
authors: Cuny
authors: Robert Koch Institute, Wernigerode, Germany.
authors: Franziska
authors: F
authors: Layer
authors: Robert Koch Institute, Wernigerode, Germany.
authors: Kevin
authors: K
authors: Kurt
authors: Institute of Microbiology and Epizootics, Free University Berlin, Berlin, Germany.
authors: Lothar H
authors: LH
authors: Wieler
authors: Institute of Microbiology and Epizootics, Free University Berlin, Berlin, Germany.
authors: Birgit
authors: B
authors: Walther
authors: Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark.
authors: Robert
authors: R
authors: Skov
authors: Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark.
authors: Jesper
authors: J
authors: Larsen
authors: National Food Institute, Technical University of Denmark, Lyngby, Denmark.
authors: Henrik
authors: H
authors: Hasman
authors: The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom.
authors: J Ross
authors: JR
authors: Fitzgerald
authors: Department of Epidemiology, College of Public Health, the University of Iowa, Iowa City, Iowa, United States of America.
authors: Tara C
authors: TC
authors: Smith
authors: Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands.
authors: J A
authors: JA
authors: Wagenaar
authors: Istituto Superiore di Sanità, Rome, Italy.
authors: Annalisa
authors: A
authors: Pantosti
authors: Centre National de Référence Staphylococcus aureus, Microbiology Department, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium.
authors: Marie
authors: M
authors: Hallin
authors: European Centre for Disease Prevention and Control, Stockholm, Sweden.
authors: Marc J
authors: MJ
authors: Struelens
authors: Department of Microbiology, Scottish MRSA Reference Laboratory (SMRSARL), Glasgow Royal Infirmary, Glasgow, United Kingdom.
authors: Giles
authors: G
authors: Edwards
authors: Labor Dr. Böse GmbH, Harsum, Germany.
authors: R
authors: R
authors: Böse
authors: Robert Koch Institute, Wernigerode, Germany.
authors: Ulrich
authors: U
authors: Nübel
authors: Robert Koch Institute, Wernigerode, Germany.
authors: Wolfgang
authors: W
authors: Witte
mesh_terms: D000818:Animals; D056426:Genetic Loci / Q000235:genetics; D006734:Horse Diseases / Q000453:epidemiology* / Q000235:genetics / Q000382:microbiology*; D006736:Horses / Q000382:microbiology*; D006762:Hospitals, Animal; D006801:Humans; D010802:Phylogeny; D011110:Polymorphism, Genetic / Q000235:genetics; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000235:genetics / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000235:genetics*