Oral streptococci formerly classified as Streptococcus sanguis have been divided into six genetic groups. Methods to identify those species by genotype are needed. This study compared restriction fragment polymorphisms of rRNA genes (ribotypes) for seven S. gordonii, three S. sanguis, four S. oralis, three S. mitis, one S. crista, and seven S. parasanguis strains classified in previous DNA hybr...

The survival of pooled plaque bacteria and a mixed suspension of Streptococcus mutans, Streptococcus sanguis, Streptococcus mitis, and Streptococcus saliuarius were tested in three transport media. A new, non-nutritive, reduced transport fluid, RTF, was compared with VMG II and SBL, two recognized transport media. Specimens were stored in several vials of each medium and held at either 10°C or ...

In this report, 30 tetracycline-resistant clinical isolates of group B Streptococcus were examined to assess the extent to which tetracycline resistance is plasmid mediated. Of these, 27 showed no physical or genetic evidence of plasmid-mediated resistance; however, one conjugative and two small (3.5 X 10(6)-dalton) multicopy non-self-transmissible tetracycline resistance plasmids were identifi...

b ackgro un d : the antimicrobial activity of silver nanoparticles has been investigated in medical fields in recent years, but there are few studies regarding its effect on oral microorganisms. the aim of the present study was to evaluate the in vitro antimicrobial and toxicity properties of nanosilver against two dental plaque microorganisms  and human gingival fibroblast (hgf) cell line. me ...

Among 418 blood culture isolates of viridans group streptococci obtained between 1995 and 1997, the in vitro rates of nonsusceptibility to penicillin, erythromycin, tetracycline, and trimethoprim-sulfamethoxazole were 28, 29, 24, and 14%, respectively. The most prevalent group (125 strains) was Streptococcus mitis, followed by Streptococcus sanguis (56 strains). For 236 (56%) strains resistant ...

The present study aimed to design, synthesize and screen specifically targeted antimicrobial peptides (STAMPs) that can selectively kill Streptococcus mutans (S. mutans) in the biofilm, and to detect protein metabolism, in order to investigate the mechanism of the antibacterial functions of STAMPs against S. mutans. A series of STAMPs were synthesized, and their effects on the selective antibac...

Extracts of certain strains of Actinobacillus actinomycetemcomitans are inhibitory to strains of Streptococcus sanguis such as S. sanguis ATCC 10556. The isolation of a protein from an A. actinomycetemcomitans sonic extract which copurified with the inhibitory activity was accomplished by preparative isoelectric focusing, Sephadex G-100 gel filtration chromatography, and preparative polyacrylam...