title: Risk factors and molecular analysis of panton-valentine leukocidin-positive methicillin-resistant Staphylococcus aureus colonization in healthy children.
abstract: BACKGROUND
  Nasal carriage of Panton-Valentine leukocidin (PVL)-positive methicillin-resistant Staphylococcus aureus (MRSA) is associated with community associated disease. The risk factors for and characteristics of PVL-positive MRSA colonization in the healthy pediatric population are not well understood.
  
  
  METHODS
  Anterior nares cultures were obtained from healthy children < or =14 years of age presenting for health maintenance visits or attending 1 of 8 kindergartens during a 3-year period. A case-control study and molecular typing studies were performed.
  
  
  RESULTS
  A total of 131 (8.1%) of 1615 children had nares cultures positive for MRSA, and 25 (1.5%) were colonized with PVL-positive MRSA. Nasal colonization of PVL-positive MRSA was significantly higher in 2006 than in 2004 (2.8% versus 0.7%; P = 0.006). By multivariate analysis, antibiotic use during the past 12 months (odds ratio, 29.37; 95% confidence interval, 10.72-80.50; P < 0.001) was the major risk factor associated with PVL-positive MRSA colonization in healthy children. Comparison of hospital MRSA strains with the community colonization strains by antimicrobial susceptibility testing, macrolide-lincosamide-streptogramin resistance gene testing, staphylococcal cassette chromosome mec typing, exotoxin profiling, and pulsed-field gel electrophoresis typing revealed that clonal spread of PVL-positive MRSA distinct from clinical hospital strains contributed to the high PVL-positive MRSA burden in the community.
  
  
  CONCLUSIONS
  Nasal PVL-positive MRSA colonization in healthy children with no relationship to the hospital setting has increased significantly in the past 3 years, suggesting that it may be a major factor in the emergence of community-acquired MRSA disease in Taiwan. Previous antibiotic use was associated with PVL-positive MRSA colonization.
authors.affiliation: Department of Pediatrics, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Wen-Tsung
authors.initials: WT
authors.lastname: Lo
authors.forename: Wei-Jen
authors.initials: WJ
authors.lastname: Lin
authors.forename: Min-Hua
authors.initials: MH
authors.lastname: Tseng
authors.forename: Sheng-Ru
authors.initials: SR
authors.lastname: Wang
authors.forename: Mong-Ling
authors.initials: ML
authors.lastname: Chu
authors.forename: Chih-Chien
authors.initials: CC
authors.lastname: Wang
mesh_terms: D001427:Bacterial Toxins / Q000235:genetics*; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004269:DNA, Bacterial / Q000032:analysis / Q000302:isolation & purification; D016521:Electrophoresis, Gel, Pulsed-Field; D005098:Exotoxins / Q000235:genetics*; D005260:Female; D006801:Humans; D007223:Infant; D007956:Leukocidins / Q000235:genetics*; D008297:Male; D016106:Methicillin Resistance / Q000235:genetics; D009296:Nasal Cavity / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D015995:Prevalence; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000145:classification / Q000187:drug effects* / Q000235:genetics; D013624:Taiwan / Q000453:epidemiology
chemical_list: D001427:Bacterial Toxins; D004269:DNA, Bacterial; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin