Enterococcus is a Gram-positive, commensal bacterium inhabiting the gastrointestinal tracts of humans and other mammals. It is a main constituent of some probiotic food supplements. E. faecalis can cause life-threatening infections in humans, especially in the nosocomial environment, where the naturally high levels of antibiotic resistance found in E. faecalis contribute to its pathogenicity. It is frequently found in root canal-treated teeth in prevalence values ranging from 30% to 90% of the cases. Root Canal-treated teeth are about nine times more likely to harbor E.

It is nonmotile, facultatively anaerobic microbe and ferments glucose without gas production and doesn’t produce a catalase reaction with hydrogen peroxide. When grown on a blood agar it can produce a pseudocatalase although this reaction is usually weak. It produces a reduction of litmus milk, but does not liquefy gelatin. It can also cause endocarditis, bladder, prostate, and epididymal infections.

It is resistant to many commonly used antimicrobial agents. Resistance to vancomycin is also becoming more common. It is usually treated with linezolid. Propolis may be effective in the treatment of VRE.