Enterococci rarely cause lower respiratory tract infections, though they are capable of colonizing the oropharynx. Respiratory tract infections due to enterococci are exceedingly unusual, but case reports of enterococcal pneumonia and lung abscess exist in patients with severe and debilitating diseases. These rare cases of enterococcal pneumonia have been described in the setting of broad-spectrum antimicrobial therapy, especially with cephalosporins, along with enteric feeding in severely debilitated patients. However, most experienced clinicians will not attribute a pneumonia to Enterococcus even if a respiratory culture returns results positive for this organism.

It is known that enterococci are not as intrinsically virulent as organisms such as Staphylococcus aureus and Streptococcus pyogenes. They do not secrete exotoxins or produce superantigens. However, studies of patients with enterococcal bacteremia have shown an attributed mortality of 31% to 37% and some studies suggest vancomycin resistance to be an independent predictor of mortality.

Although enterococci do not generally cause trouble in the respiratory tract, infection at other sites can be clinically significant. Enterococci can cause catheter-related bloodstream infections. These organisms adhere to heart valves and renal epithelial cells and thus can cause endocarditis and urinary tract infections. Enterococci are commonly found in cultures of intra-abdominal and pelvic infections. It is thought that enterococci act synergistically with other bacteria in intra-abdominal sepsis to enhance morbidity and mortality. Enterococci by themselves rarely, if ever, cause cellulitis or other soft-tissue infections. They are frequently isolated from mixed cultures in surgical wound infections, decubitus ulcers, and diabetic foot infections, but their significance is difficult to assess in these cases.