Video - Streptococcus viridans

Streptococcus viridans is a group of gram-positive, alpha-hemolytic streptococci that is commonly found in the oropharynx, epithelial surfaces of the oral cavity, teeth, skin, the gastrointestinal and genitourinary tract of humans. The term streptococcus viridans �, refers to five groups of Streptococci that include Streptococcus anginosus group, the mitis group, the sanguinis group, the salivarius group, and the mutans group.

S. viridans is part of the normal human microbiota and usually does not cause disease, however, it has been implicated in causing several infections, especially in immunocompromised individuals. S. viridans dental caries, periodontal disease, brain and liver abscesses, and bacterial endocarditis.

Some strains of S. viridans are capable of forming biofilms on medical implants such as catheters and prosthetic heart valves, which can offer them some antibiotic resistance. Treatment of S. viridans infections typically involves antibiotics such as penicillin, vancomycin, or erythromycin.