title: Molecular Characterization of Invasive Staphylococcus aureus Infection in Central New York Children: Importance of Two Clonal Groups and Inconsistent Presence of Selected Virulence Determinants.
abstract: BACKGROUND
  The genetic makeup of circulating Staphylococcus aureus (SA) populations varies by region. The extent to which SA virulence determinants contribute to the severity of pediatric infections is poorly understood. The study objective was to describe the genetic population of invasive SA (ISA) isolates from children in the Central New York (CNY) area and the prevalence of selected virulence genes.
  
  
  METHODS
  Clinical and demographic information for hospitalized children <19 years of age with community-onset or community-associated ISA infections, determined from clinical microbiology records, was extracted from medical records from Upstate Golisano Children's Hospital in CNY. Antibiotic susceptibility was assessed, and available isolates were genotyped and tested for the presence of selected virulence determinants. Associations between clinical and laboratory findings were evaluated using standard statistical techniques.
  
  
  RESULTS
  Ninety patients with ISA disease diagnosed between 2007 and 2010 were included in the study; 74% were due to methicillin-susceptible SA (MSSA). The most common clinical diagnosis was bacteremia. Fifty-seven of 90 isolates were available for further testing. The SA pulsed-field gel electrophoresis type, agr type, and clonal complexes most commonly isolated were USA300 (n = 25, 44%), agr1 (n = 30, 52%), and CC8 (n = 25, 44%), respectively. USA300 strains were more likely to be associated with deep abscesses (P = .007), whereas non-USA300 strains were associated with medical device infections (P = .018). Isolates from patients with deep abscesses and pneumonia were more likely to carry luk-PV genes (P = .023 and P = .051, respectively).
  
  
  CONCLUSIONS
  MSSA remains an important problem of pediatric ISA infection in our region and results from genetically diverse SA populations.
authors.affiliation: Department of Pediatrics, State University of New York Upstate Medical University, Syracuse, New York.
authors.forename: Manika
authors.initials: M
authors.lastname: Suryadevara
authors.affiliation: University of Arizona, Tucson, Arizona.
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Clark
authors.affiliation: BIO5 Institute and Department of Pathology, University of Arizona, Tucson, Arizona.
authors.forename: Donna M
authors.initials: DM
authors.lastname: Wolk
authors.affiliation: University of Arizona, Tucson, Arizona.
authors.forename: Aubri
authors.initials: A
authors.lastname: Carman
authors.affiliation: Department of Public Health and Preventive Medicine, Upstate Medical University, Syracuse, New York.
authors.forename: Paula F
authors.initials: PF
authors.lastname: Rosenbaum
authors.affiliation: Department of Pediatrics, State University of New York Upstate Medical University, Syracuse, New York.
authors.forename: Jana
authors.initials: J
authors.lastname: Shaw
keywords: Children; Invasive; MRSA; MSSA; S aureus; USA300; Virulence Determinants