title: Urease and Dental Plaque Microbial Profiles in Children.
abstract: OBJECTIVE
  Urease enzymes produced by oral bacteria generate ammonia, which can have a significant impact on the oral ecology and, consequently, on oral health. To evaluate the relationship of urease with dental plaque microbial profiles in children as it relates to dental caries, and to identify the main contributors to this activity.
  
  
  METHODS
  82 supragingival plaque samples were collected from 44 children at baseline and one year later, as part of a longitudinal study on urease and caries in children. DNA was extracted; the V3-V5 region of the 16S rRNA gene was amplified and sequenced using 454 pyrosequencing. Urease activity was measured using a spectrophotometric assay. Data were analyzed with Qiime.
  
  
  RESULTS
  Plaque urease activity was significantly associated with the composition of the microbial communities of the dental plaque (Baseline P = 0.027, One Year P = 0.012). The bacterial taxa whose proportion in dental plaque exhibited significant variation by plaque urease levels in both visits were the family Pasteurellaceae (Baseline P<0.001; One Year P = 0.0148), especially Haemophilus parainfluenzae. No association was observed between these bacteria and dental caries. Bacteria in the genus Leptotrichia were negatively associated with urease and positively associated with dental caries (Bonferroni P<0.001).
  
  
  CONCLUSIONS
  Alkali production by urease enzymes primarily from species in the family Pasteurellaceae can be an important ecological determinant in children's dental plaque. Further studies are needed to establish the role of urease-associated bacteria in the acid/base homeostasis of the dental plaque, and in the development and prediction of dental caries in children.
authors.affiliation: School of Dental Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico, United States of America.
authors.forename: Evangelia
authors.initials: E
authors.lastname: Morou-Bermudez
authors.affiliation: School of Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico, United States of America.
authors.forename: Selena
authors.initials: S
authors.lastname: Rodriguez
authors.affiliation: School of Dental Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico, United States of America.
authors.forename: Angel S
authors.initials: AS
authors.lastname: Bello
authors.affiliation: New York University School of Medicine, New York, New York, United States of America; University of Puerto Rico Rio Piedras Campus, San Juan, Puerto Rico, United States of America.
authors.forename: Maria G
authors.initials: MG
authors.lastname: Dominguez-Bello
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D003731:Dental Caries / Q000382:microbiology; D003773:Dental Plaque / Q000382:microbiology*; D005260:Female; D014644:Genetic Variation; D054884:Host-Pathogen Interactions; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D064307:Microbiota / Q000235:genetics / Q000502:physiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D014510:Urease / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D012336:RNA, Ribosomal, 16S; D014510:Urease