The cell wall polysaccharides of certain oral streptococci function as receptors for the lectin-like surface adhesins on other members of the oral biofilm community. Recognition of these receptor polysaccharides (RPS) depends on the presence of a host-like motif, either GalNAcbeta1-3Gal (Gn) or Galbeta1-3GalNAc (G), within the oligosaccharide repeating units of different RPS structural types. T...

BACKGROUND Population analysis of viridans streptococci is important because these species are associated with dental caries, bacteremia, and subacute endocarditis, in addition to being important members of the human oral commensal microbiota. DESIGN In this study, we phylogenetically analyzed the rod shape-determining protein gene (rodA), which is associated with cellular morphology, cell di...

Structural characterization of Streptococcus pneumoniae capsular polysaccharides (CPS) is a prerequisite for unraveling both antigenic and genetic relationships that exist between different serotypes. In the current study, comparative structural studies of S. pneumoniae CPS serogroup 10 (CPS10) were extended to include genetically related S. pneumoniae CPS34, CPS39, and CPS47F. High-resolution ...

Tropical forests are species-rich reserves for the discovery and development of antimicrobial drugs. The aim of this work is to investigate the in vitro antimicrobial potential of Amazon plants found within the National Institute on Amazon Research's Adolpho Ducke forest reserve, located in Manaus, state of Amazonas, Brazil. 75 methanol, chloroform and water extracts representing 12 plant speci...

Major predisposing conditions for infective endocarditis (IE) are the presence of a cardiac platelet-fibrin vegetation and of circulating bacteria with relatively low susceptibility to microbicidal activity of blood platelets. The influence of proinflammatory conditions on development of IE is unknown. We studied the effects of the presence of a catheter, inserted to induce platelet-fibrin vege...

Recurrence of acute otitis media (RAOM) is a relevant issue in the clinical practice. "Bacteriotherapy" has been proposed as an option in children with RAOM. Streptococcus salivarius 24SMB nasal spray has been previously demonstrated to reduce the risk of acute otitis media (AOM) in otitis-prone children. The current retrospective and observational study aimed to confirm this outcome in a real-...

The two recently characterized Streptococcus pneumoniae strains--R6Chi and R6Cho(-)--that have lost the unique auxotrophic requirement of this bacterial species for choline differ in their mechanisms of choline independence. In strain R6Chi the mechanism is caused by a point mutation in tacF, a gene that is part of the pneumococcal lic2 operon, which is essential for growth and survival of the ...