title: Exploring the oral bacterial flora: current status and future directions.
abstract: OBJECTIVE
  The oral cavity forms an indispensable part of the human microbiome, for its unique and diverse microflora distributed within various niches. While majority of these organisms exhibit commensalism, shifts in bacterial community dynamics cause pathological changes within oral cavity and distant sites. The aim of this review was to appraise the current and emerging methods of detecting bacteria of the oral cavity paying particular attention to the cultivation independent methods.
  
  
  METHODS
  Literature pertaining to cultivation based and cultivation independent methods of oral bacterial identification was reviewed.
  
  
  METHODS
  The specific advantages and disadvantages of cultivation based, microscopic, immunological and metagenomic identification methods were appraised.
  
  
  RESULTS
  Because of their fastidious and exacting growth requirements, cultivation based studies grossly underestimate the extent of bacterial diversity in these polymicrobial infections. Culture independent methods deemed more sensitive in identifying difficult to culture and novel bacterial species.
  
  
  CONCLUSIONS
  Apart from characterizing potentially novel bacterial species, the nucleic acid sequence data analyzed using various bioinformatics protocols have revealed that there are in excess of 700 bacterial species inhabiting the mouth. Moreover, the latest pyrosequencing based methods have further broadened the extent of bacterial diversity in oral niches.
authors.affiliation: Oral Biosciences, Faculty of Dentistry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong (SAR), China.
authors.forename: N B
authors.initials: NB
authors.lastname: Parahitiyawa
authors.forename: C
authors.initials: C
authors.lastname: Scully
authors.forename: W K
authors.initials: WK
authors.lastname: Leung
authors.forename: W C
authors.initials: WC
authors.lastname: Yam
authors.forename: L J
authors.initials: LJ
authors.lastname: Jin
authors.forename: L P
authors.initials: LP
authors.lastname: Samaranayake
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000254:growth & development; D001431:Bacteriological Techniques; D044822:Biodiversity; D006801:Humans; D054892:Metagenome; D056186:Metagenomics; D009055:Mouth / Q000382:microbiology*; D009059:Mouth Diseases / Q000382:microbiology; D014076:Tooth Diseases / Q000382:microbiology