Enterococcus faecalis, often shortened to E. faecalis, is a common bacterium. It is found naturally in the human gastrointestinal tract and various environments. While generally harmless in the gut, it can act as an opportunistic pathogen, causing serious infections under certain conditions.
Where Enterococcus Faecalis Lives
E. faecalis primarily resides in the human gastrointestinal tract, where it lives in harmony with its host. It is a natural part of the gut microbiota, a diverse community of microorganisms that aids in various bodily functions. It can also be found in other human body sites like the mouth and vagina, though typically in smaller quantities.
Beyond the human body, E. faecalis is widespread in soil, water, and animals. It can survive in diverse and challenging conditions, including high temperatures, salty environments, and acidic conditions. Its adaptability allows it to persist on inanimate surfaces, particularly in healthcare settings.
E. faecalis transitions from a harmless resident to a cause of infection when opportunities arise. This often occurs in individuals with weakened immune systems or in hospital environments. Its pathogenicity is linked to its ability to adapt, colonize surfaces, and evade the host’s immune response.
Infections Enterococcus Faecalis Causes
E. faecalis causes several types of infections, particularly in healthcare settings. Urinary Tract Infections (UTIs) are common, frequently affecting hospitalized patients, especially those with urinary catheters. Catheters provide surfaces for E. faecalis to form biofilms, allowing the bacteria to adhere and evade immune responses and antibiotic treatments.
Another serious infection is Endocarditis, an inflammation of the heart’s inner lining or valves. E. faecalis is a leading cause of infective endocarditis, often requiring combination antibiotic therapy. It can also lead to Bacteremia, a bloodstream infection. Bacteremia can sometimes progress to sepsis, a severe and life-threatening response to infection.
Surgical Site Infections are also a concern, as E. faecalis can enter open cuts during surgery. These infections can arise in various locations, including intra-abdominal and pelvic areas. In dentistry, E. faecalis is frequently linked to persistent Root Canal Infections, especially in teeth with previous root canal treatment. Its presence in these cases can range from 30% to 90%, contributing to treatment failure.
Treating Enterococcus Faecalis Infections
Treatment of E. faecalis infections typically involves antibiotics, but is complicated by the bacterium’s inherent and acquired resistance to many common drugs. E. faecalis is intrinsically resistant to several antibiotic classes, including oxazolidinones, quinolones, and most beta-lactams like cephalosporins. This makes antibiotic selection challenging.
The emergence of Vancomycin-Resistant Enterococci (VRE) is a significant public health concern, particularly Enterococcus faecium, though E. faecalis can also acquire vancomycin resistance. VRE infections are especially difficult to treat due to limited antibiotic options. Linezolid and daptomycin are often considered for VRE infections, with daptomycin sometimes used in combination with beta-lactam antibiotics to enhance its activity.
Susceptibility testing is performed to guide antibiotic selection, determining which antibiotics will be effective against a specific E. faecalis strain. For severe or resistant infections, combination therapy with multiple antibiotics may be necessary to achieve a bactericidal effect, especially in cases like endocarditis or meningitis. For example, ampicillin combined with an aminoglycoside like gentamicin has historically been a standard approach for susceptible E. faecalis endocarditis.
Preventing Enterococcus Faecalis Infections
Preventing E. faecalis infections relies on infection control measures, particularly in healthcare environments. Hand hygiene protocols for healthcare workers are important, as hands can become contaminated with pathogens during patient care. Environmental cleaning and disinfection of surfaces also help reduce the spread of the bacterium, which can survive for extended periods in hospital settings.
For patients infected or colonized with resistant strains like VRE, isolation precautions are implemented. This involves placing affected patients in private rooms and ensuring healthcare workers use gloves and gowns when entering the room. Avoiding the sharing of non-critical medical items between patients further mitigates transmission.
General hygiene practices are also important for the public, especially for vulnerable individuals or those with chronic health conditions. Maintaining good personal hygiene, particularly hand washing after using the bathroom, helps prevent bacterial spread. Antibiotic stewardship also plays a role by promoting the appropriate use of antibiotics to slow the development and spread of resistant strains.