Isolation and Identification of Oral Bacteria and Characterization for Bacteriocin Production and Antimicrobial Sensitivity

Abstract

Oral bacteria play an important role in body homeostasis and the bacterial genus Streptococcus is the
dominant microflora commonly found in oral bacterial community. Their ability to establish biofilm lifestyle in the
oral cavity by outcompeting other bacteria has been attributed to the production of bacteriocin along with other
strategies. The goal of the present study was to isolate and identify oral bacteria and characterize their ability to
produce bacteriocin against other oral bacteria as well as their sensitivity to common antibiotics. We have employed
deferred antagonism bacteriocin assay for bacteriocin production and disk diffusion assay for antibiotic susceptibility
testing. We identified eight bacterial strains belonging to the genera Streptococcus and Enterococcus based on colony
morphology, biochemical assays, 16S rDNA sequence analysis, and species-specific PCR. Antibiotic susceptibility
assay indicated that some of the strains are resistant to one or more antibiotics. Our study also revealed that the
isolated strains are capable of producing one or more bacteriocins against other oral bacteria. Further molecular and
biochemical studies are required to understand the nature of observed bacteriocin.