Enterococcus faecalis – formerly classified as part of the group D Streptococcus system – is a Gram-positive, bacterium inhabiting the gastrointestinal tracts of humans and other mammals.
E. faecalis is found in most healthy individuals, but can cause endocarditis and sepsis, urinary tract infections (UTIs), meningitis, and other infections in humans. Enterococci have emerged as a major cause of nosocomial infections, and within this group Enterococcus faecalis causes the majority of human enterococcal infections. The most common infection caused by Enterococci is infection of the urinary tract. E. faecalis can cause lower urinary tract infections (UTI), such as cystisis, prostatitis, and epididymitis. E. faecalis are also found in intra-abdominal, pelvic, and soft tissue infections. The E. faecalis can cause nosocomial bacteremia. The source of bacteremia is most often the urinary tract, occurring from an infected intravenous catheter. Endocarditis is the most serious enterococcal infection, as it causes inflammation of the heart valves.
E. faecalis is resistant to many commonly used antimicrobial agents.