title: Genomic insights into the emergence and spread of international clones of healthcare-, community- and livestock-associated meticillin-resistant Staphylococcus aureus: Blurring of the traditional definitions.
abstract: The evolution of meticillin-resistant Staphylococcus aureus (MRSA) from meticillin-susceptible S. aureus has been a result of the accumulation of genetic elements under selection pressure from antibiotics. The traditional classification of MRSA into healthcare-associated MRSA (HA-MRSA) and community-associated MRSA (CA-MRSA) is no longer relevant as there is significant overlap of identical clones between these groups, with an increasing recognition of human infection caused by livestock-associated MRSA (LA-MRSA). Genomic studies have enabled us to model the epidemiology of MRSA along these lines. In this review, we discuss the clinical relevance of genomic studies, particularly whole-genome sequencing, in the investigation of outbreaks. We also discuss the blurring of each of the three epidemiological groups (HA-MRSA, CA-MRSA and LA-MRSA), demonstrating the limited relevance of this classification.
authors.affiliation: Department of Microbiology, University Hospital Crosshouse, Lister Street, Kilmarnock KA2 0BE, UK. Electronic address: abhijit.bal@nhs.net.
authors.forename: A M
authors.initials: AM
authors.lastname: Bal
authors.affiliation: School of Veterinary and Life Sciences, Murdoch University, and Department of Microbiology, Fiona Stanley Hospital, Western Australia, Australia.
authors.forename: G W
authors.initials: GW
authors.lastname: Coombs
authors.affiliation: School of Medicine, University of St Andrews, St Andrews KY16 9TF, UK.
authors.forename: M T G
authors.initials: MTG
authors.lastname: Holden
authors.affiliation: Institute of Infection and Immunity, St George's, University of London, Cranmer Terrace, London SW17 0RE, UK.
authors.forename: J A
authors.initials: JA
authors.lastname: Lindsay
authors.affiliation: Pathology Queensland Central Laboratory and Griffith University School of Medicine, Queensland, Australia.
authors.forename: G R
authors.initials: GR
authors.lastname: Nimmo
authors.affiliation: Infectious Diseases and Intensive Care Unit, Pontchaillou University Hospital, 35033 Rennes, France.
authors.forename: P
authors.initials: P
authors.lastname: Tattevin
authors.affiliation: Statens Serum Institut, 5 Artillerivej, DK-2300 Copenhagen S, Denmark.
authors.forename: R L
authors.initials: RL
authors.lastname: Skov
mesh_terms: D000818:Animals; D017714:Community-Acquired Infections / Q000382:microbiology; D023281:Genomics; D006801:Humans; D058751:Livestock / Q000382:microbiology; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics*; D013203:Staphylococcal Infections / Q000453:epidemiology*
keywords: MRSA clones; MRSA epidemiology; Whole-genome sequencing