Experimental endocarditis induction and platelet aggregation by Streptococcus anginosus, Streptococcus constellatus and Streptococcus intermedius

Abstract

A total of 18 'Streptococcus milleri' strains including the ATCC type strains of Streptococcus anginosus, Streptococcus constellatus and Streptococcus intermedius were compared with Streptococcus oralis ATCC10557 for their ability to induce infective endocarditis in catheterized rats. Three days after intravenous injection of 10(8) colony-forming units all 8 S. anginosus strains tested produced infective vegetations and bacteremia in almost all rats whereas 5 S. constellatus strains and the S. oralis strain produced infective vegetations and bacteremia less frequently and 5 S. intermedius strains only occasionally. The vegetations infected with the S. anginosus strains harbored microbial cells in significantly higher numbers that those with the other strains. No strong correlation was found between the endocardial infectivity and platelet-aggregating capacity of these strains. The platelet-aggregating strains were members of the Lancefield groups F and G or ungroupable but not of group A or C.

Use of Phylogenetic and Phenotypic Analyses To Identify Nonhemolytic Streptococci Isolated from Bacteremic Patients

“…Many of the species of these five clusters are major constituents of the commensal microbiota of the human oral cavity and upper respiratory tract and are occasionally implicated in various pathologies. The anginosus group, formerly called "Streptococcus milleri" in some parts of the world (16), includes three recognized species (Streptococcus anginosus, Streptococcus intermedius, and Streptococcus constellatus) that are primarily associated with suppurative infections of tissues of the mouth and various body sites, including the meninges (9,37,44,54,56). The mitis group currently includes…”

“…Many of the species of these five clusters are major constituents of the commensal microbiota of the human oral cavity and upper respiratory tract and are occasionally implicated in various pathologies. The anginosus group, formerly called "Streptococcus milleri" in some parts of the world (16), includes three recognized species (Streptococcus anginosus, Streptococcus intermedius, and Streptococcus constellatus) that are primarily associated with suppurative infections of tissues of the mouth and various body sites, including the meninges (9,37,44,54,56 Although they are commensals of the upper respiratory tract, S. pneumoniae is a major cause of both local and systemic infections and several of the other mitis group streptococci have long been recognized as important etiologic agents of subacute bacterial endocarditis (2,13); septicemia, particularly in neutropenic cancer patients (5,6,29); occasional cases of meningitis (8); and eye infections (1). The two species of the salivarius group associated with humans (Streptococcus salivarius and Streptococcus vestibularis) are usually considered to be of low virulence, although occasional life-threatening infections such as bacteremia and meningitis have been reported (11,43).…”

Contribution of Sialic Acid-Binding Adhesin to Pathogenesis of Experimental Endocarditis Caused by Streptococcus gordonii DL1

“…No significant differences were found among DL1, DL1R2, and EM230 in growth rate and viable count after reaching the stationary phase (data not shown). Bacterial cells were harvested, washed, and suspended in sterile saline as previously described (12), except that streptococci were suspended at a density of 10 7 or 10 8 CFU/ml of saline. Catheter-induced heart valve vegetations were produced in male Sprague-Dawley rats (350 to 450 g; Charles River Japan, Inc., Yokohama, Japan) as previously described (8,20), with some modifications by Kitada et al (12).…”

“…Bacterial cells were harvested, washed, and suspended in sterile saline as previously described (12), except that streptococci were suspended at a density of 10 7 or 10 8 CFU/ml of saline. Catheter-induced heart valve vegetations were produced in male Sprague-Dawley rats (350 to 450 g; Charles River Japan, Inc., Yokohama, Japan) as previously described (8,20), with some modifications by Kitada et al (12). Groups of animals were inoculated 24 h after catheterization by intravenous injection of 0.5 ml of saline containing 5 ϫ 10 6 or 5 ϫ 10 7 CFU of S. gordonii DL1R2 or EM230, a 1:1 mixture of both strains (2.5 ϫ 10 7 CFU of each strain), or saline only (sham infected).…”

Infective endocarditis due to a rare pathogen, Streptococcus constellatus, in a patient with gingivitis: A case report and review of the literature

“…Among the Streptococcus spp., Streptococci viridans are the main cause of IE [3]. However, 1 group of S. viridans, the S. milleri group, which includes S. constellatus, S. anginosus, and S. intermedius, rarely cause IE; among these, S. anginosus is predominant [4]. S. constellatus is a very rare pathogen of IE; there are only 10 case reports in the literature [5][6][7][8][9][10][11][12][13][14].…”