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Characterization of Streptococcus gordonii prophage PH15: complete genome sequence and functional analysis of

Jan R van der Ploeg1

  • 1Institute of Oral Biology, University of Zürich, Plattenstrasse 11, 8032 Zürich, Switzerland.

Microbiology (Reading, England)
|October 4, 2008
PubMed

Insights

Researchers identified a novel bacteriophage, PH15, in Streptococcus gordonii. This phage exhibits potential for controlling oral streptococcal infections, including pathogens like Streptococcus mutans.

Area of Science:

  • Microbiology
  • Virology
  • Genomics

Background:

  • Streptococcus gordonii, a common inhabitant of dental plaque, can harbor prophages.
  • Prophages are viral DNA integrated into the host genome, which can influence bacterial properties.

Purpose of the Study:

  • To characterize the prophage PH15 found in Streptococcus gordonii OMZ1039.
  • To investigate the integration mechanism and potential therapeutic applications of phage PH15 components.

Main Methods:

  • Induction of prophage excision using mitomycin C.
  • Whole-genome sequencing of bacteriophage PH15.
  • Site-specific integration assays using a constructed plasmid.
  • Purification and testing of phage endolysin activity.

Main Results:

  • The complete genome of PH15 (39,136 bp, 61 ORFs) was determined, revealing similarity to other temperate phages.
  • PH15 integrates into the cysteinyl-tRNA gene of S. gordonii.
  • A plasmid facilitated site-specific integration into various oral streptococcal species.
  • Purified phage endolysin inhibited the growth of multiple streptococcal species, including pathogens.

Conclusions:

  • Bacteriophage PH15 is a novel Siphoviridae phage with a characterized genome and integration site.
  • The phage's integration system and endolysin show promise for developing novel strategies against oral streptococcal infections.

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