title: Effect of Streptococcus sanguinis/Porphyromonas gingivalis single and combined biofilms upon platelet aggregation.
abstract: OBJECTIVE
  To assess the effect of two oral bacteria Streptococcus sanguinis and Porphyromonas gingivalis upon platelet aggregation.
  
  
  METHODS
  Streptococcus sanguinis, P. gingivalis, S. sanguniis+P. gingivalis were added to platelet-rich plasma and platelet aggregation measured using a platelet aggregometer. Platelets were passed through a flow chamber with S. sanguinis, P. gingivalis or a biofilm of S. sanguinis and P. gingivalis coated with saliva. Platelet adhesion to the chamber was observed under a fluorescence microscope for 15min. The positive control was platelets treated with adrenaline; the negative control was platelets treated with phosphate-buffered saline.
  
  
  RESULTS
  The mean (± s.e.) aggregation magnitude of S. sanguinis and P. gingivalis was 77.7±7.4% and 79.3±9.9%, respectively. The aggregation magnitude of S. sanguinis+P. gingivalis was 51.3±12.9%, which was significantly lower than that for S. sanguinis/P. gingivalis (P<0.05). In the flow chamber system, platelets adhered to S. sanguinis/P.gingivalis respectively within 3min, and reached a plateau at 5-15min. Under the condition of the S. sanguinis- and P. gingivalis-saliva biofilm, platelet adhesion to the biofilm was significantly reduced at 5-15min (P<0.05).
  
  
  CONCLUSIONS
  In the static or dynamic flow system, platelets adhered to S. sanguinis or P. gingivalis. However, if S. sanguinis was mixed with P. gingivalis, the aggregation magnitude (%) was significantly reduced.
authors.affiliation: Department of Dentistry and Periodontics, Affiliated Hospital of Stomatology, Medical College, Zhejiang University, Hangzhou, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Tu
authors.forename: W
authors.initials: W
authors.lastname: Huang
authors.forename: Z
authors.initials: Z
authors.lastname: Pan
authors.forename: H
authors.initials: H
authors.lastname: Hu
authors.forename: H
authors.initials: H
authors.lastname: Chen
mesh_terms: D000328:Adult; D001431:Bacteriological Techniques; D018441:Biofilms; D006801:Humans; D059013:Microbial Consortia / Q000502:physiology; D010973:Platelet Adhesiveness / Q000502:physiology; D010974:Platelet Aggregation / Q000502:physiology*; D053657:Platelet-Rich Plasma / Q000382:microbiology; D016966:Porphyromonas gingivalis / Q000502:physiology*; D012212:Rheology / Q000295:instrumentation; D012463:Saliva / Q000502:physiology; D013298:Streptococcus sanguis / Q000502:physiology*