Identification of Streptococcus sanguinis genes required for biofilm formation and examination of their role in endocarditis virulence

Xiuchun Ge, Todd Kitten, Zhenming Chen, Sehmi P. Lee, Cindy L. Munro, Ping Xu

Research output: Contribution to journalArticle

49 Scopus citations


Streptococcus sanguinis is one of the pioneers in the bacterial colonization of teeth and is one of the most abundant species in the oral biofilm called dental plaque. S. sanguinis is also the most common viridans group streptococcal species implicated in infective endocarditis. To investigate the association of biofilm and endocarditis, we established a biofilm assay and examined biofilm formation with a signature-tagged mutagenesis library of S. sanguinis. Four genes that have not previously been associated with biofilm formation in any other bacterium, purB, purL, thrB, and pyrE, were putatively identified as contributing to in vitro biofilm formation in S. sanguinis. By examining 800 mutants for attenuation in the rabbit endocarditis model and for reduction in biofilm formation in vitro, we found some mutants that were both biofilm defective and attenuated for endocarditis. However, we also identified mutants with only reduced biofilm formation or with only attenuation in the endocarditis model. This result indicates that the ability to form biofilms in vitro is not associated with endocarditis virulence in vivo in S. sanguinis.

Original languageEnglish (US)
Pages (from-to)2551-2559
Number of pages9
JournalInfection and Immunity
Issue number6
StatePublished - Jun 1 2008


ASJC Scopus subject areas

  • Parasitology
  • Microbiology
  • Immunology
  • Infectious Diseases

Cite this