title: Clarifying the transmission route of Staphylococcus aureus colonizing the skin in early childhood atopic dermatitis.
abstract: BACKGROUND
  We previously found that skin-colonizing Staphylococcus aureus in early childhood atopic dermatitis (AD) originates predominantly from the patient's nose, whereas maternal transmission did not contribute substantially to colonization.
  
  
  OBJECTIVE
  To investigate the transmission route and definitive source of skin-colonizing S aureus in early childhood AD.
  
  
  METHODS
  A total of 527 children and 32 healthy teachers from 2 kindergartens and 1 elementary school were included in the study. Children were screened for AD and categorized into 3 groups (AD, borderline, and healthy). Samples were collected from 5 to 6 different body sites, including the skin, subungual spaces, and anterior nares. The identity of colonies apparent on mannitol salt agar plates was confirmed by polymerase chain reaction amplification of the nuc gene. The genotypic composition of cultured isolates was examined by pulsed-field gel electrophoresis and analyzed with a dendrogram.
  
  
  RESULTS
  The total colonization rate was higher in the AD group (34.6%) than in the borderline (21.1%) and healthy groups (25.4%). In the AD group, S aureus was more frequently cultured from the subungual areas (30.8%) than the anterior nares (19.2%). To assess self-contamination or recolonization, dendrogram analysis revealed that most isolate pairs (22/23) had the same pulsed-field gel electrophoresis pattern.
  
  
  CONCLUSIONS
  As with the anterior nares, the subungual spaces are important reservoir of skin-colonizing S aureus in early childhood AD. The transmission route for self-contamination or recolonization of S aureus appears to be from children's anterior nares to the skin through their own fingers. Child-to-child and/or teacher-to-child transmission in a classroom do not seem to be definite routes of S aureus transmission.
authors.affiliation: Department of Dermatology, School of Medicine, Pusan National University, Busan, South Korea.
authors.forename: Byung Soo
authors.initials: BS
authors.lastname: Kim
authors.forename: Jee Young
authors.initials: JY
authors.lastname: Park
authors.forename: Chang Hyun
authors.initials: CH
authors.lastname: Song
authors.forename: Jun Young
authors.initials: JY
authors.lastname: Kim
authors.forename: Hyun Jung
authors.initials: HJ
authors.lastname: Lim
authors.forename: Hae Sook
authors.initials: HS
authors.lastname: Lee
authors.forename: Weon Ju
authors.initials: WJ
authors.lastname: Lee
authors.forename: Seok-Jong
authors.initials: SJ
authors.lastname: Lee
authors.forename: Hee Young
authors.initials: HY
authors.lastname: Kang
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Kim
authors.forename: Won Jeong
authors.initials: WJ
authors.lastname: Kim
authors.forename: Do Won
authors.initials: DW
authors.lastname: Kim
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D003876:Dermatitis, Atopic / Q000382:microbiology*; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods; D005178:Faculty; D006801:Humans; D008836:Micrococcal Nuclease / Q000235:genetics; D009666:Nose / Q000382:microbiology; D013207:Staphylococcal Skin Infections / Q000382:microbiology* / Q000635:transmission*; D013211:Staphylococcus aureus / Q000235:genetics / Q000254:growth & development*
chemical_list: D001426:Bacterial Proteins; C074002:nuc protein, staphylococcus; D008836:Micrococcal Nuclease