title: Molecular epidemiology of methicillin-resistant and methicillin-susceptible Staphylococcus aureus isolates from global clinical trials.
abstract: Determining the genetic characteristics of Staphylococcus aureus is important for better understanding of the global and dynamic epidemiology of this organism as we witness the emergence and spread of virulent and antibiotic-resistant clones. We genotyped 292 S. aureus isolates (105 methicillin resistant and 187 methicillin susceptible) using a combination of pulsed-field gel electrophoresis, multilocus sequence typing, and SCCmec typing. In addition, S. aureus isolates were tested for the presence of the Panton-Valentine leukocidin (PVL) genes. Isolates were recovered from patients with uncomplicated skin infections in 10 different countries during five phase III global clinical trials of retapamulin, a new topical antibiotic agent. The most common methicillin-resistant clone had multilocus sequence type 8, pulsed-field type USA300, and SCCmec type IV and possessed the PVL genes. This clone was isolated exclusively in the United States. The most common PVL-positive, methicillin-susceptible clone had multilocus sequence type 121 and pulsed-field type USA1200. This clone was found primarily in South Africa and the Russian Federation. Other clones were found at lower frequencies and were limited in their geographic distribution. Overall, considerable genetic diversity was observed within multilocus sequence type clonal complexes and pulsed-field types.
authors.affiliation: Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, NE 68178, USA. rgoering@creighton.edu
authors.forename: Richard V
authors.initials: RV
authors.lastname: Goering
authors.forename: Ribhi M
authors.initials: RM
authors.lastname: Shawar
authors.forename: Nicole E
authors.initials: NE
authors.lastname: Scangarella
authors.forename: F Patrick
authors.initials: FP
authors.lastname: O'Hara
authors.forename: Heather
authors.initials: H
authors.lastname: Amrine-Madsen
authors.forename: Joshua M
authors.initials: JM
authors.lastname: West
authors.forename: Marybeth
authors.initials: M
authors.lastname: Dalessandro
authors.forename: Julie A
authors.initials: JA
authors.lastname: Becker
authors.forename: Stacey L
authors.initials: SL
authors.lastname: Walsh
authors.forename: Linda A
authors.initials: LA
authors.lastname: Miller
authors.forename: Stephanie F
authors.initials: SF
authors.lastname: van Horn
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Thomas
authors.forename: Monique E
authors.initials: ME
authors.lastname: Twynholm
mesh_terms: D006801:Humans; D007194:India / Q000453:epidemiology; D016106:Methicillin Resistance / Q000235:genetics; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics*; D017720:Molecular Epidemiology; D012867:Skin / Q000382:microbiology; D013019:South Africa / Q000453:epidemiology; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology; D013211:Staphylococcus aureus / Q000235:genetics*