Isolation and identification of culturable bacterial flora of dental lesions in a clinic

Background &

Dental plaque is structurally and functionally a biofilm that may lead to caries and root infection due to disruption of microbial homeostasis. The present research aimed to investigate the molecular characteristics of dental flora of patients in East Tehran.Materials &

In this cross-sectional study, 9 samples of dental plaque, caries, and root canal from five patients who were randomly selected in 2017 were collected under sterile  conditions. Bacteria were cultured using the standard BHI broth culture medium. General primers of the 16S rRNA gene were used for molecular identification of bacteria and investigation of their phylogenetic relationships. Demographic characteristics of the subjects were also examined.

Thirteen bacterial isolates were identified from clinical specimens of plaque and tooth decay. The isolated bacteria belonged to three phyla, five families, six genera Arthrobacter, Brevundimonas, Granulicatella, Kocuria, Neisseria, and Streptococcus, as well as seven species. The most abundant isolates were N. perflava (n=5) and S. salivarius (n=3). The identified bacteria were arranged in four branches of a phylogenetic tree. No association was found between bacteria and demographic characteristics.

Identifying the factors involved in dental infections is an effective approach to prevention. In this study, 11 bacterial isolates from dental plaque and 2 bacterial isolates from tooth decay were identified and no strains from the root specimens were identified. The  discrepancy between plaque bacteria and caries may be due to the small sample size and  microbiological methods used.