title: Genetic variability in beta-defensins is not associated with susceptibility to Staphylococcus aureus bacteremia.
abstract: BACKGROUND
  Human beta-defensins are key components of human innate immunity to a variety of pathogens, including Staphylococcus aureus. The aim of the present study was to investigate a potential association between gene variations in DEFB1 and DEFB103/DEFB4 and the development of S. aureus bacteremia (SAB) employing a case-control design.
  
  
  METHODS
  Cases were unique patients with documented SAB, identified with the National S. aureus Bacteremia Register, a comprehensive dataset of all episodes of community associated-SABs (CA-SAB) occurring in children (≤20 yrs) in Denmark from 1990 to 2006. Controls were age-matched healthy individuals with no history of SAB. DNA obtained from cases and controls using the Danish Newborn Screening Biobank were genotyped for functional polymorphisms of DEFB1 by Sanger sequencing and copy number variation of the DEFB103 and DEFB4 genes using Pyrosequencing-based Paralogue Ratio Test (P-PRT).
  
  
  RESULTS
  193 ethnic Danish SAB cases with 382 age-matched controls were used for this study. S. aureus isolates represented a variety of bacterial (i.e., different spa types) types similar to SAB isolates in general. DEFB1 minor allele frequencies of rs11362 (cases vs. controls 0.47/0.44), rs1800972 (0.21/0.24), and rs1799946 (0.32/0.33) were not significantly different in cases compared with controls. Also, DEFB4/DEFB103 gene copy numbers (means 4.83/4.92) were not significantly different in cases compared with controls.
  
  
  CONCLUSIONS
  Using a large, unique cohort of pediatric CA-SAB, we found no significant association between DEFB1 genetic variation or DEFB4/DEFB103 gene copy number and susceptibility for SAB.
authors.affiliation: Department for Microbiological Surveillance and Research, Statens Serum Institut, Copenhagen, Denmark.
authors.forename: Peder
authors.initials: P
authors.lastname: Fode
authors.forename: Anders Rhod
authors.initials: AR
authors.lastname: Larsen
authors.forename: Bjarke
authors.initials: B
authors.lastname: Feenstra
authors.forename: Cathrine
authors.initials: C
authors.lastname: Jespersgaard
authors.forename: Robert Leo
authors.initials: RL
authors.lastname: Skov
authors.forename: Marc
authors.initials: M
authors.lastname: Stegger
authors.forename: Vance G
authors.initials: VG
authors.lastname: Fowler
authors.forename: Paal Skytt
authors.initials: PS
authors.lastname: Andersen
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D016470:Bacteremia / Q000175:diagnosis* / Q000235:genetics / Q000382:microbiology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003718:Denmark; D005260:Female; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007113:Immunity, Innate; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008957:Models, Genetic; D015997:Neonatal Screening; D017422:Sequence Analysis, DNA; D013203:Staphylococcal Infections / Q000175:diagnosis* / Q000235:genetics / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000378:metabolism*; D023083:beta-Defensins / Q000378:metabolism*
chemical_list: D023083:beta-Defensins