Gemella: A genus that has been reclassified into BACILLALES incertae sedis because of its ambiguous taxonomy. Previously it was considered part of the Staphylococcaceae family.Staphylococcaceae: Family of gram-positive, facultatively anaerobic bacteria, in the order Bacillales. Genera include Gemella, Macrococcus, Salinicoccus, and STAPHYLOCOCCUS.Gram-Positive Cocci: Coccus-shaped bacteria that retain the crystal violet stain when treated by Gram's method.Carnobacteriaceae: A family of gram-positive, lactic acid-producing bacteria in the order Lactobacillales. It includes both high-pressure-loving species (piezophiles) found in the deep ocean, and Antarctic species.Abiotrophia: A genus of gram-positive, facultatively anaerobic bacteria in the family Aerococcaceae.Brain Abscess: A circumscribed collection of purulent exudate in the brain, due to bacterial and other infections. The majority are caused by spread of infected material from a focus of suppuration elsewhere in the body, notably the PARANASAL SINUSES, middle ear (see EAR, MIDDLE); HEART (see also ENDOCARDITIS, BACTERIAL), and LUNG. Penetrating CRANIOCEREBRAL TRAUMA and NEUROSURGICAL PROCEDURES may also be associated with this condition. Clinical manifestations include HEADACHE; SEIZURES; focal neurologic deficits; and alterations of consciousness. (Adams et al., Principles of Neurology, 6th ed, pp712-6)Streptococcaceae: A family of gram-positive non-sporing bacteria including many parasitic, pathogenic, and saprophytic forms.RNA, Ribosomal, 16S: Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.Endocarditis, Bacterial: Inflammation of the ENDOCARDIUM caused by BACTERIA that entered the bloodstream. The strains of bacteria vary with predisposing factors, such as CONGENITAL HEART DEFECTS; HEART VALVE DISEASES; HEART VALVE PROSTHESIS IMPLANTATION; or intravenous drug use.Mouth: The oval-shaped oral cavity located at the apex of the digestive tract and consisting of two parts: the vestibule and the oral cavity proper.DNA, Ribosomal: DNA sequences encoding RIBOSOMAL RNA and the segments of DNA separating the individual ribosomal RNA genes, referred to as RIBOSOMAL SPACER DNA.Genes, rRNA: Genes, found in both prokaryotes and eukaryotes, which are transcribed to produce the RNA which is incorporated into RIBOSOMES. Prokaryotic rRNA genes are usually found in OPERONS dispersed throughout the GENOME, whereas eukaryotic rRNA genes are clustered, multicistronic transcriptional units.Abscess: Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.