Pili of oral Streptococcus sanguinis bind to fibronectin and contribute to cell adhesion.
Streptococcus sanguinis is a predominant bacterium in the human oral cavity and occasionally causes infective endocarditis. We identified a unique cell surface polymeric structure named pili in this species and investigated its functions in regard to its potential virulence. Pili of S. sanguinis strain SK36 were shown to be composed of three distinctive pilus proteins (PilA, PilB, and PilC), and a pili-deficient mutant demonstrated reduced bacterial adherence to HeLa and human oral epithelial cells. PilC showed a binding ability to fibronectin, suggesting that pili are involved in colonization by this species. In addition, ATCC10556, a standard S. sanguinis strain, was unable to produce pili due to defective pilus genes, which indicates a diversity of pilus expression among various S. sanguinis strains.
Okahashi
Nobuo
N
Department of Oral Frontier Biology, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita-Osaka 565-0871, Japan. okahashi@dent.osaka-u.ac.jp
Nakata
Masanobu
M
Sakurai
Atsuo
A
Terao
Yutaka
Y
Hoshino
Tomonori
T
Yamaguchi
Masaya
M
Isoda
Ryutaro
R
Sumitomo
Tomoko
T
Nakano
Kazuhiko
K
Kawabata
Shigetada
S
Ooshima
Takashi
T
D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D005353:Fibronectins / Q000097:blood / Q000378:metabolism*; D010861:Fimbriae, Bacterial / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D009055:Mouth / Q000382:microbiology*; D013298:Streptococcus sanguis / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*
D001426:Bacterial Proteins; D005353:Fibronectins