Background Viridans group streptococci (VGS) are commensal flora of the upper respiratory tract in humans and can cause serious infections, like infective endocarditis, septicemia, and meningitis. Accurate identification of VGS to the species level is difficult because they share many physiological characteristics. We report a study using sequencing of 16S ribosomal DNA (rDNA) gene and sodA gen...

Infective endocarditis (IE) is relatively uncommon; however, when it diagnosed, usually among those with known cardiac valvular abnormalities. The most common pathogens that cause are streptococci (mainly viridans), enterococci, and other species. An extremely rare pathogen could IE Granulicatella. This gram-positive coccus classically inhabits human mucosal surfaces only rarely causes disease....

This review traces the history of the human, nonhemolytic, or viridans, streptococci and describes improvements in their taxonomy wrought by study of their biochemical profiles and analysis of their nucleic acids. The goal was to define species on the basis of genetic relationships and to describe these species by their phenotypic characteristics so that they can be easily identified. This meth...

Single-doses or short-term administration of beta-lactam antibiotics alone or combined with aminoglucoside antibiotics have failed to consistently prevent experimental streptococcal endocarditis induced by high inocula of bacteria poorly susceptible to killing by these antibiotics. The optimal duration of administration of antibiotics for successful prophylaxis under these circumstances has not...

Seven strains of viridans streptococci of the species Streptococcus sanguis, S. mutans and S. mitis were investigated for autolysis. The effect of pH, salt concentration and temperature on the autolytic process was studied in Na2HPO4/NaH2PO4 buffer. Whole cells and walls of all strains autolysed most rapidly at pH values above 7. Autolysis of whole cells of S. sanguis and one strain of S. mitis...