Molecular characterization of oral bacteria isolated from human saliva

Abstract

Periodontitis is an inflammation of gums and bones that supporting the teeth which caused by Staphylococcus intermedius. The saliva from a patient of periodontitis or suspect to periodontitis will have higher levels of Staphylococcus intermedius. Hence, human saliva is clinically informative in diagnosing oral disease and the oral health of an individual. In this study, oral bacteria in human saliva were identified using 16S ribosomal RNA. 16S ribosomal RNA (rRNA) genes from the isolated colonies were amplified through the colony Polymerase Chain Reaction (PCR) method. 16S rRNA genes were used to determine species identity by sequencing and generating the phylogenetic tree. The results showed that Streptococcus sp. and Staphylococcus sp. were the most prevalent oral bacteria found from all the saliva samples, while Lactobacillus sp. was found from two samples. From the constructed phylogenetic trees, bacteria strains B1 and B2 clustered with the Staphylococcus sp. database. Bacteria strains B9 and B10 were categorized as Streptococcus sp. as the confidential level between Streptococcus sp. database is 100% in Neighbour-Joining tree. Sample B15 and B16 clustered with Lactobacillus sp. database. Oral bacteria species typically associated with periodontitis was detected in all saliva samples. Therefore, it is important to fully understand the nature of the oral bacteria before further research on drug design and administration of oral treatment is executed.