title: MRSA epidemic linked to a quickly spreading colonization and virulence determinant.
abstract: The molecular processes underlying epidemic waves of methicillin-resistant Staphylococcus aureus (MRSA) infection are poorly understood(1). Although a major role has been attributed to the acquisition of virulence determinants by horizontal gene transfer(2), there are insufficient epidemiological and functional data supporting that concept. We here report the spread of clones containing a previously extremely rare(3,4) mobile genetic element–encoded gene, sasX. We demonstrate that sasX has a key role in MRSA colonization and pathogenesis, substantially enhancing nasal colonization, lung disease and abscess formation and promoting mechanisms of immune evasion. Moreover, we observed the recent spread of sasX from sequence type 239 (ST239) to invasive clones belonging to other sequence types. Our study identifies sasX as a quickly spreading crucial determinant of MRSA pathogenic success and a promising target for therapeutic interference. Our results provide proof of principle that horizontal gene transfer of key virulence determinants drives MRSA epidemic waves.
authors.affiliation: Department of Laboratory Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, China.
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.forename: Xin
authors.initials: X
authors.lastname: Du
authors.forename: Amer E
authors.initials: AE
authors.lastname: Villaruz
authors.forename: Binh An
authors.initials: BA
authors.lastname: Diep
authors.forename: Decheng
authors.initials: D
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Song
authors.forename: Yueru
authors.initials: Y
authors.lastname: Tian
authors.forename: Jinhui
authors.initials: J
authors.lastname: Hu
authors.forename: Fangyou
authors.initials: F
authors.lastname: Yu
authors.forename: Yuan
authors.initials: Y
authors.lastname: Lu
authors.forename: Michael
authors.initials: M
authors.lastname: Otto
mesh_terms: D000818:Animals; D002681:China; D005260:Female; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D051379:Mice; D008812:Mice, Hairless; D008813:Mice, Inbred ICR; D014774:Virulence