title: Environmental bacteria and childhood asthma.
abstract: BACKGROUND
  We have previously found an inverse association of bacterial diversity with childhood asthma. It remains unclear whether certain bacteria account for the protective effect.
  
  
  METHODS
  The high variability of the bacterial 16S rRNA gene allows assessing diversity and specificity of bacterial communities by single-strand configuration polymorphism (SSCP). DNA was extracted from mattress dust samples of 489 school-age children from rural and suburban regions in Germany. A fragment of the bacteria-specific 16S rRNA gene was amplified by PCR, digested to single-strand DNA, and subjected to electrophoresis. The resulting band patterns reflect the underlying DNA sequences. The individual bands were tested for associations with asthma, hay fever, and atopy in quantitative and qualitative multivariable analyses. Significantly associated bands were isolated and sequenced. The sequences were compared to a database, and distinct bacteria were identified.
  
  
  RESULTS
  Seven of 76 independent bands were found to be inversely associated with asthma, atopic sensitization, and hay fever with odds ratios ranging from 0.17 to 0.73. The bands contained the sequences of Acinetobacter sp., Lactobacillus spp., Neisseria spp., Staphylococcus sciuri, Jeotgalicoccus sp., Corynebacterium spp., and others.
  
  
  CONCLUSIONS
  In a diverse microbial environment, certain bacteria may account for the protective effect on the development of asthma and atopy.
authors.affiliation: University Children's Hospital Munich, Munich, Germany. markus.ege@med.uni-muenchen.de
authors.forename: M J
authors.initials: MJ
authors.lastname: Ege
authors.forename: M
authors.initials: M
authors.lastname: Mayer
authors.forename: K
authors.initials: K
authors.lastname: Schwaiger
authors.forename: J
authors.initials: J
authors.lastname: Mattes
authors.forename: G
authors.initials: G
authors.lastname: Pershagen
authors.forename: M
authors.initials: M
authors.lastname: van Hage
authors.forename: A
authors.initials: A
authors.lastname: Scheynius
authors.forename: J
authors.initials: J
authors.lastname: Bauer
authors.forename: E
authors.initials: E
authors.lastname: von Mutius
mesh_terms: D001249:Asthma / Q000276:immunology* / Q000382:microbiology*; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000276:immunology*; D002648:Child; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology / Q000382:microbiology; D007073:Immunoglobulin E / Q000276:immunology; D008297:Male; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S
chemical_list: D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D007073:Immunoglobulin E