title: Staphylococcal aureusEnterotoxin C and Enterotoxin-Like L Associated with Post-partum Mastitis.
abstract: Denmark is a low prevalence country with regard to methicillin resistantStaphylococcus aureus(MRSA). In 2008 and 2014, two neonatal wards in the Copenhagen area experienced outbreaks with a typical community acquired MRSA belonging to the samespatype and sequence type (t015:ST45) and both were PVL and ACME negative. In outbreak 1, the isolates harbored SCCmecIVa and in outbreak 2 SCCmecV. The clinical presentation differed between the two outbreaks, as none of five MRSA positive mothers in outbreak 1 had mastitis vs. five of six MRSA positive mothers in outbreak 2 (p< 0.02). To investigate if whole-genome sequencing could identify virulence genes associated with mastitis, t015:ST45 isolates from Denmark (N= 101) were whole-genome sequenced. Sequence analysis confirmed two separate outbreaks with no sign of sustained spread into the community. Analysis of the accessory genome between isolates from the two outbreaks revealed aS. aureuspathogenicity island containing enterotoxin C and enterotoxin-like L only in isolates from outbreak 2. Enterotoxin C and enterotoxin-like L carryingS. aureusare associated with bovine mastitis and our findings indicate that these may also be important virulence factors for human mastitis.
authors.affiliation: Department of Clinical Microbiology, Herlev and Gentofte Hospital, University of Copenhagen Herlev, Denmark.
authors.forename: Kristina T
authors.initials: KT
authors.lastname: Franck
authors.affiliation: Department of Clinical Microbiology, Hvidovre Hospital, University of Copenhagen Hvidovre, Denmark.
authors.forename: Heidi
authors.initials: H
authors.lastname: Gumpert
authors.affiliation: Department of Clinical Microbiology, Herlev and Gentofte Hospital, University of Copenhagen Herlev, Denmark.
authors.forename: Bente
authors.initials: B
authors.lastname: Olesen
authors.affiliation: Reference Laboratory for Antimicrobial Resistance and Staphylococci, Statens Serum Institut Copenhagen, Denmark.
authors.forename: Anders R
authors.initials: AR
authors.lastname: Larsen
authors.affiliation: Reference Laboratory for Antimicrobial Resistance and Staphylococci, Statens Serum Institut Copenhagen, Denmark.
authors.forename: Andreas
authors.initials: A
authors.lastname: Petersen
authors.affiliation: Department of Clinical Microbiology, Herlev and Gentofte Hospital, University of Copenhagen Herlev, Denmark.
authors.forename: Jette
authors.initials: J
authors.lastname: Bangsborg
authors.affiliation: Department of Pediatrics, Nordsjællands Hospital, University of Copenhagen Hillerød, Denmark.
authors.forename: Per
authors.initials: P
authors.lastname: Albertsen
authors.affiliation: Department of Clinical Microbiology, Hvidovre Hospital, University of CopenhagenHvidovre, Denmark; Faculty of Health Sciences, Institute of Clinical Medicine, University of CopenhagenCopenhagen, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Westh
authors.affiliation: Department of Clinical Microbiology, Hvidovre Hospital, University of Copenhagen Hvidovre, Denmark.
authors.forename: Mette D
authors.initials: MD
authors.lastname: Bartels
keywords: MRSA; SaPITokyo12571; clinical presentation; enterotoxins; pathogenicity islands; post-partum mastitis; virulence; whole-genome sequencing