title: Shedding of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus from adult and pediatric bathers in marine waters.
abstract: BACKGROUND
  Staphylococcus aureus including methicillin resistant S. aureus, MRSA, are human colonizing bacteria that commonly cause opportunistic infections primarily involving the skin in otherwise healthy individuals. These infections have been linked to close contact and sharing of common facilities such as locker rooms, schools and prisons Waterborne exposure and transmission routes have not been traditionally associated with S. aureus infections. Coastal marine waters and beaches used for recreation are potential locations for the combination of high numbers of people with close contact and therefore could contribute to the exposure to and infection by these organisms. The primary aim of this study was to evaluate the amount and characteristics of the shedding of methicillin sensitive S. aureus, MSSA and MRSA by human bathers in marine waters.
  
  
  RESULTS
  Nasal cultures were collected from bathers, and water samples were collected from two sets of pools designed to isolate and quantify MSSA and MRSA shed by adults and toddlers during exposure to marine water. A combination of selective growth media and biochemical and polymerase chain reaction analysis was used to identify and perform limited characterization of the S. aureus isolated from the water and the participants. Twelve of 15 MRSA isolates collected from the water had identical genetic characteristics as the organisms isolated from the participants exposed to that water while the remaining 3 MRSA were without matching nasal isolates from participants. The amount of S. aureus shed per person corresponded to 105 to 106 CFU per person per 15-minute bathing period, with 15 to 20% of this quantity testing positive for MRSA.
  
  
  CONCLUSIONS
  This is the first report of a comparison of human colonizing organisms with bacteria from human exposed marine water attempting to confirm that participants shed their own colonizing MSSA and MRSA into their bathing milieu. These findings clearly demonstrate that adults and toddlers shed their colonizing organisms into marine waters and therefore can be sources of potentially pathogenic S. aureus and MRSA in recreational marine waters. Additional research is needed to evaluate recreational beaches and marine waters as potential exposure and transmission pathways for MRSA.
authors.affiliation: Department of Pediatrics, University of Miami, Miami, Florida 33130, USA. lplano@med.miami.edu
authors.forename: Lisa R W
authors.initials: LR
authors.lastname: Plano
authors.forename: Anna C
authors.initials: AC
authors.lastname: Garza
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Shibata
authors.forename: Samir M
authors.initials: SM
authors.lastname: Elmir
authors.forename: Jonathan
authors.initials: J
authors.lastname: Kish
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Sinigalliano
authors.forename: Maribeth L
authors.initials: ML
authors.lastname: Gidley
authors.forename: Gary
authors.initials: G
authors.lastname: Miller
authors.forename: Kelly
authors.initials: K
authors.lastname: Withum
authors.forename: Lora E
authors.initials: LE
authors.lastname: Fleming
authors.forename: Helena M
authors.initials: HM
authors.lastname: Solo-Gabriele
mesh_terms: D000328:Adult; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D009666:Nose / Q000382:microbiology; D012623:Seawater / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000302:isolation & purification*; D014871:Water Microbiology