The susceptibility of viridans group streptococci to macrolides was determined. Thirteen isolates (17%) were resistant to erythromycin. Five strains carried an erm gene that was highly homologous to that in Tn917. Four strains had mefE genes that coded erythromycin efflux ability.

An analysis of 13 immunoglobulin A1 (IgA1) protease genes (iga) of strains of Streptococcus pneumoniae, Streptococcus oralis, Streptococcus mitis, and Streptococcus sanguis was carried out to obtain information on the structure, polymorphism, and phylogeny of this specific protease, which enables bacteria to evade functions of the predominant Ig isotype on mucosal surfaces. The analysis include...

Following the induction of aortic insufficiency, 15 dogs received intravenous injections of either Staphylococcus aureus or Streptococcus mitis. The clinical course and pathologic picture resembled those of acute and subacute bacterial endocarditis respectively. The valvular lesions were confined largely to contacting surfaces of aortic and mitral leaflets. The dogs given S. mitis often develop...

Strain Marseille-P2915T, a Gram-positive, facultative anaerobic and nonmotile coccus, was isolated from the gastric lavage of a patient with severe anaemia. The 16S rRNA and rpoB gene comparison exhibited a sequence identity of 98.7 and 92.6% with Streptococcus infantis strain JCM 10157T, respectively, collocating it within the 'Streptococcus mitis' group. On the basis of phenotypic and genomic...

Despite the benefits of MALDI-TOF MS technology (Matrix-Assisted Laser Desorption-Ionization Time-Of-Flight Mass Spectrometry) reported worldwide and the continuous improving of the available databases, discrimination between Streptococcus pneumoniae and closely related species within the Streptococcus mitis group (SMG) using this methodology has been suboptimal. However, the accurate identific...

A comparative study of 60 strains of nutritionally variant streptococci (NVS) with 34 strains of Streptococcus mitis and 37 strains of Streptococcus sanguis II showed the presence of a red chromophore which was absent in the other streptococcal species. By using the conventional microbiological tests, only small differences were found between the NVS and the two other related species. In contra...

BACKGROUND Non-mutans low pH oral streptococci are postulated to contribute to caries etiology. OBJECTIVE This study was undertaken to investigate whether the acidogenicity and acid tolerance of clinical strains of Streptococcus oralis and Streptococcus mitis correlate with health or early-stage enamel caries. DESIGN S. oralis and S. mitis were isolated from plaque samples taken from the oc...