Streptococcus sanguinis
Encyclopedia
Streptococcus sanguinis, formerly known as Streptococcus sanguis, is a Gram-positive
facultative aerobic coccus
species of bacteria and a member of the Viridans Streptococcus
group. S. sanguinis is a normal inhabitant of the healthy human mouth where it is particularly found in dental plaque
, where it modifies the environment to make it less hospitable for other strains of Streptococcus that cause cavities
, such as Streptococcus mutans
. S. sanguinis may gain entrance to the bloodstream when opportunity presents (dental cleanings and surgeries) and colonize the heart valves, particularly the mitral and aortic valve
s, where it is the most common cause of subacute bacterial endocarditis
. For this reason, oral surgeons often prescribe a short course of antibiotics to be taken a few days before to a few days after oral surgery. Once an infection has occurred, treatment is much more complicated and generally involves the administration of several weeks of penicillin
and aminoglycoside
antibiotics. The complete genomic sequence
of S. sanguinis was determined in 2007 by laboratories at Virginia Commonwealth University
.
Gram-positive
Gram-positive bacteria are those that are stained dark blue or violet by Gram staining. This is in contrast to Gram-negative bacteria, which cannot retain the crystal violet stain, instead taking up the counterstain and appearing red or pink...
facultative aerobic coccus
Coccus
Coccus can be used to describe any bacterium that has a spherical shape. It is one of the three distinct types of bacteria shapes, the other two being bacillus and spirillum cells...
species of bacteria and a member of the Viridans Streptococcus
Streptococcus viridans
Viridans Streptococcus is a pseudotaxonomic non-Linnaenan term for a large group of commensal streptococcal bacteria that are either α-hemolytic, producing a green coloration on blood agar plates , or nonhemolytic...
group. S. sanguinis is a normal inhabitant of the healthy human mouth where it is particularly found in dental plaque
Dental plaque
Dental plaque is a biofilm, usually a pale yellow, that develops naturally on the teeth. Like any biofilm, dental plaque is formed by colonizing bacteria trying to attach themselves to a smooth surface...
, where it modifies the environment to make it less hospitable for other strains of Streptococcus that cause cavities
Dental caries
Dental caries, also known as tooth decay or a cavity, is an irreversible infection usually bacterial in origin that causes demineralization of the hard tissues and destruction of the organic matter of the tooth, usually by production of acid by hydrolysis of the food debris accumulated on the...
, such as Streptococcus mutans
Streptococcus mutans
Streptococcus mutans is a facultatively aerobic, Gram-positive coccus-shaped bacterium commonly found in the human oral cavity and is a significant contributor to tooth decay.The microbe was first described by J Kilian Clarke in 1924.-Introduction:...
. S. sanguinis may gain entrance to the bloodstream when opportunity presents (dental cleanings and surgeries) and colonize the heart valves, particularly the mitral and aortic valve
Aortic valve
The aortic valve is one of the valves of the heart. It is normally tricuspid , although in 1% of the population it is found to be congenitally bicuspid . It lies between the left ventricle and the aorta....
s, where it is the most common cause of subacute bacterial endocarditis
Endocarditis
Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves . Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, or even on intracardiac devices...
. For this reason, oral surgeons often prescribe a short course of antibiotics to be taken a few days before to a few days after oral surgery. Once an infection has occurred, treatment is much more complicated and generally involves the administration of several weeks of penicillin
Penicillin
Penicillin is a group of antibiotics derived from Penicillium fungi. They include penicillin G, procaine penicillin, benzathine penicillin, and penicillin V....
and aminoglycoside
Aminoglycoside
An aminoglycoside is a molecule or a portion of a molecule composed of amino-modifiedsugars.Several aminoglycosides function as antibiotics that are effective against certain types of bacteria...
antibiotics. The complete genomic sequence
Genome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....
of S. sanguinis was determined in 2007 by laboratories at Virginia Commonwealth University
Virginia Commonwealth University
Virginia Commonwealth University is a public university located in Richmond, Virginia. It comprises two campuses in the Downtown Richmond area, the product of a merger between the Richmond Professional Institute and the Medical College of Virginia in 1968...
.