NAME: Enterococcus faecalis and Enterococcus faecium
SYNONYM OR CROSS REFERENCE: Nonhemolytic streptococci, gamma haemolytic streptococci, enterococcus, group D streptococci, vancomycin-resistant enterococcus (VRE). Formerly known as Streptococcus faecalis and Streptococcus faecium(1).
CHARACTERISTICS: Enterococcus spp. are facultatively anaerobic, catalase-negative Gram- positive cocci, arranged individually, in pairs, or short chains(1,2). Optimal temperature for growth of E. faecalis and E. faecium is 35°C(2). E. faecalis and E. faecium are normal inhabitants of the intestinal tract, female genital tract, and (less commonly) oral cavity(1-3).
PATHOGENICITY/TOXICITY: Enterococci can cause urinary tract, wound, and soft tissue infections(2,4). They are also associated with bacteremia which can lead to endocarditis in previously damaged cardiac valves(4). E. faecalis is the most frequent species isolated from human intestine samples (80-90%), E. faecium accounts for 5-10% of isolates(1,2).
EPIDEMIOLOGY: Worldwide distribution(2). Enterococci are opportunistic pathogens which affect elderly patients with underlying disease and other immunocompromised patients who have been hospitalized for long periods, treated with invasive devices, or received broad-spectrum antibiotics(2). Enterococci are common nosocomial pathogens, accounting for 10% of hospital- acquired infections in the USA(5). Enterococci are consistently the second or third most common agent in urinary tract infections, wound infections, and bacteremia in hospitals. They are responsible for about 16% of nosocomial urinary tract infections(2).
HOST RANGE: Humans, pets and livestock(6).
INFECTIOUS DOSE: Unknown.
MODE OF TRANSMISSION: Nosocomial and person-to-person transmission; can also be transmitted on food products(7).
INCUBATION PERIOD: Unknown.
COMMUNICABILITY: Yes, can be transmitted from person-to-person(7).
ZOONOSIS: Very likely that Enterococcus can be transmitted from animals to humans(8).
DRUG SUSCEPTIBILITY: Most strains remain susceptible to penicillin, ampicillin, and vancomycin.
DRUG RESISTANCE: Strains resistant to β-lactams, aminoglycosides and, increasingly, vancomycin have been described(2,4). Strains have also been identified which carry genetic elements conferring resistance to chloramphenicol, tetracyclines, macrolides, lincosamides, quinolones, and streptogramins(2).
SUSCEPTIBILITY/RESISTANCE TO DISINFECTANTS: Susceptible to 70% isopropyl alcohol, 70% ethanol, 0.041% sodium hypochlorite, phenolic and quaternary ammonia compounds, and glutaraldehyde. Resistant to 3% hydrogen peroxide(9,10).
PHYSICAL INACTIVATION: Enterococci are killed by temperatures in excess of 80°C(10).
SURVIVAL OUTSIDE HOST: Enterococci can grow and survive in harsh environments, and can persist almost anywhere including soil, plants, water, and food(2). Can survive 5 days to 4 months on dry inanimate surfaces(11).
Note: All diagnostic methods are not necessarily available in all countries.
FIRST AID/TREATMENT: Treatment with penicillin or ampicillin for infections such as urinary tract infection, peritonitis, and wound infections. Combination therapy of a cell wall- active agent (penicillin, ampicillin or vancomycin) and an aminoglycoside is required for the treatment of endocarditis and possibly meningitis(2,12).
LABORATORY-ACQUIRED INFECTIONS: No cases have been reported; however, Pike reported 78 cases with 4 deaths associated with Streptococcus spp. before E. faecalis and E. faecium were placed in the Enterococcus genus(13).
SOURCES/SPECIMENS: Blood, urine, wound samples, and feces(2).
PRIMARY HAZARDS: Accidental parenteral inoculation or ingestion.
SPECIAL HAZARDS: None.
RISK GROUP CLASSIFICATION: Risk Group 2(14).
CONTAINMENT REQUIREMENTS: Containment Level 2 facilities, equipment, and operational practices for work involving infectious or potentially infectious materials, animals, or cultures(15).
PROTECTIVE CLOTHING: Lab coat. Gloves when direct skin contact with infected materials or animals is unavoidable. Eye protection must be used where there is a known or potential risk to splashes(15).
OTHER PRECAUTIONS: All procedures that may produce aerosols, or involve high concentrations or large volumes should be conducted in a biological safety cabinet (BSC). The use of needles, syringes, and other sharp objects should be strictly limited(15). Additional precautions should be considered with work involving animals or large scale activities.
SPILLS: Allow aerosols to settle. Wearing protective clothing, gently cover spill with paper towels and apply an appropriate disinfectant, starting at perimeter and working towards the centre. Allow sufficient contact time before clean up(15).
DISPOSAL: Decontaminate before disposal - steam sterilization, incineration, chemical disinfection(15).
STORAGE: In sealed containers that are appropriately labelled(15).
REGULATORY INFORMATION: The import, transport, and use of pathogens in Canada is regulated under many regulatory bodies, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment Canada, and Transport Canada. Users are responsible for ensuring they are compliant with all relevant acts, regulations, guidelines, and standards.
UPDATED: November 2010
PREPARED BY: Pathogen Regulation Directorate, PHAC.
Although the information, opinions and recommendations contained in this Pathogen Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.
Public Health Agency of Canada, 2010