title: Utilization of a continuous streptococcal surface to measure interbacterial adherence in vitro and in vivo.
abstract: Cell-to-cell interactions are essential for the formation of dental plaque. A continuous layer of Streptococcus sanguis SA-1 cells fixed to a solid surface has been used to evaluate interactions among this bacterium, Haemophilus parainfluenzae, and Streptococcus sobrinus. S. sanguis cells were attached to a Falcon 3001 tissue culture plates or bovine enamel chips, coated with a biological adhesive. Scanning electron microscopy of the chips showed the streptococci as a contiguous surface. Radiolabeled bacteria were used to measure a second-species interbacterial adherence to the streptococcal-coated culture plates. Strains of H. parainfluenzae known to coaggregate (strain HP-28) and not to coaggregate (strains HP-42 and HP-80), in suspension with S. sanguis strain SA-1, were studied for adherence. Ten-fold-higher numbers of coaggregating strain HP-28 adhered in vitro to the streptococcal layer than did the non-coaggregating strains. S. sobrinus strain 6715 did not show appreciable adherence to the S. sanguis surface. Saliva did not affect the adherence of coaggregating or non-coaggregating H. parainfluenzae strains to S. sanguis strain SA-1. Bovine enamel chips, coated with streptococci, mounted on modified orthodontic appliances and placed in the mouths of three volunteers, facilitated the measurement of interbacterial adherence in vivo of streptomycin-resistant strains of H. parainfluenzae (HP-28R or HP-42R). Suspensions of bacteria were placed into the mouth, distributed throughout, and expectorated. After 15 or 120 minutes, the appliance with the chips was removed, the chips sonified, and colony-forming units (CFU) of streptomycin-resistant haemophili determined per chip.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Microbiology Program, School of Dentistry, University of Minnesota, Minneapolis 55455.
authors.forename: W F
authors.initials: WF
authors.lastname: Liljemark
authors.forename: C G
authors.initials: CG
authors.lastname: Bloomquist
authors.forename: M C
authors.initials: MC
authors.lastname: Coulter
authors.forename: L J
authors.initials: LJ
authors.lastname: Fenner
authors.forename: R J
authors.initials: RJ
authors.lastname: Skopek
authors.forename: C F
authors.initials: CF
authors.lastname: Schachtele
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D002417:Cattle; D002462:Cell Membrane / Q000502:physiology; D015169:Colony Count, Microbial; D003743:Dental Enamel; D006190:Haemophilus / Q000502:physiology*; D012463:Saliva / Q000502:physiology; D013291:Streptococcus / Q000502:physiology*; D013295:Streptococcus mutans / Q000502:physiology; D013298:Streptococcus sanguis / Q000502:physiology*