Enterococcus faecalis also known as Group D Streptococcus (cocci) is a Gram-positive commensal bacterium inhabiting the gastrointestinal tracts of humans an other mammals. Like other species in the genus Enterococcus, E. faecalis can cause life-threatening infections in humans and monkeys, especially in the nosocomial (hospital) environment: the naturally high levels of antibiotic resistance found in E. faecalis contribute to its pathogenicity. E. faecalis presents as a non-motile microorganism that is facultatively anaerobic, it ferments glucose without gas production, and does not produce a catalase reaction with hydrogen peroxide. E. faecalis displays gamma hemolysis (γ-hemolysis). It produces a reduction of litmus milk, but does not liquefy gelatin. Growth of nutrient broth is consistent with being facultatively anaerobic.