Detection and Culture of Novel Oral Bacteria
from: Oral Microbial Ecology: Current Research and New Perspectives (Edited by: Nicholas S. Jakubovics and Robert J. Palmer Jr.). Caister Academic Press, U.K. (2013)
The oral microbiota is highly diverse and includes fungi, protozoa, viruses and bacteria. Both domains of prokaryotes, Archaea and Bacteria are present. Representatives of the Archaea are restricted to a few taxa in the genus Methanobrevibacter, while there are over 600 species of Bacteria, from at least 12 phyla. The full diversity of bacterial populations in the mouth has been recognised following the application of culture-independent methods of analysis, based on 16S rRNA gene sequence comparisons. Because oral bacteria are typically slow-growing and fastidious, and around half cannot be grown in the laboratory at all, the taxonomic process of classifying and naming bacterial species is ongoing and over 100 cultivable taxa have still to be named. In recent years, attempts have been made to culture the not-yet-cultured portion of the microbiota. There are a number of reasons why certain taxa are uncultivable and these include a need for a specific nutrient, extreme oxygen sensitivity and dependence on other organisms. The inter-dependence among members of the oral microbial community may relate to cooperative degradation of natural substrates for growth or the need to participate in signalling networks that control growth rate and resuscitation from dormancy. Novel culture media and methods are being developed that reproduce the in vivo environment and thus encourage previously uncultured organisms to grow in the laboratory read more ...