Identification of Streptococcus sobrinus Lytic Bacteriophages Isolated From Caspian Sea

Objectives: The aggregation of oral Streptococci results in initiation of decalcification of tooth enamel, dental caries and periodontal diseases. The bacteriophages have considerable effects in controlling the populations of various bacteria. The aim of this study was to detect Streptococcus sobrinus bacteriophages.

Methods: Dental plaque samples were collected and cultured in Brain Heart Infusion Broth. The Caspian Sea water sample was gathered, centrifuged and its supernatant was filtered through a 0.45 μm membrane filter. The filtrates were added to Streptococcus sobrinus suspension and cultured using overlay method.

Results: Transmission electron microscopy revealed specific lytic bacteriophages that attacked Streptococcus sobrinus we isolated from dental plaques. These bacteriophages were included coat, core and an appendage with a droplet-shaped measuring 75 – 81.25 nm in diameter and 93.75 – 100 nm in length and were most probably related to family Guttaviridae of bacteriophages.  

Conclusions: This is the first report of isolation and identification of oral Streptococci bacteriophages from Caspian Sea located in the north of Iran. The applications of these lytic phages could be considered as a potential for phage therapy of dental plaque.