Enterococcus faecalis is a facultative (aerobic and anaerobic) bacteria normally found in the intestines, however it can be found in the mouth or vagina/urinary tract, being a cause of urinary tract infections and aerobic vaginitis (linked to bacterial vaginosis).
E. faecalis, like lactobacilli, produce lactic acid and hydrogen peroxide.
When found in healthy people, in normal amounts, E. faecalis is not believed to cause a problem, however in some circumstances, E. faecalis can pose at worst a life-threatening risk of infection, and at “best” uncomfortable vulvovaginal or urinary tract symptoms including odour and inflammation.
Just two species out of 17 enterococci are found in humans: E. faecalis and E. faecium, with some species of E. faecalis considered probiotics, being used in research for various medical purposes.
Understanding when you have a probiotic bacteria, or a normal element of your flora, and when you have an infection can be difficult. It is likely to come down to what else is found in your vagina: if you have a lot of lactobacilli present, you may have the normal kind; if you have an aerobic vaginitis or bacterial vaginosis-type presentation (odour, discharge, irritation), with few or no lactobacilli, you may have the other kind.
Symptoms of genitourinary E. faecalis infection
- Pelvic infections (vaginal, urethral, etc.)
- Urinary tract infections (UTIs)
- Painful urination
- Vaginal odour (may smell like faeces or off)
- Inflammation signs – itching, burning, discharge
General body symptoms of E. faecalis infection (not present for vulvovaginal infections only)
- Stomach cramping
- Abdominal infections
- Mouth and gum infections, particularly after a root canal
- Septicaemia – blood poisoning
- Infections in wounds
- Endocarditis – heart lining infection
- Enterococcal meningitis – brain infection, uncommon
- Presence of bacteria in the blood (via test)
Treatment of vulvovaginal E. faecalis and antibiotic resistance
E. faecalis has natural and acquired antibiotic resistance, and can tolerate a range of conditions including changes in temperature and pH. E. faecalis develops biofilms, and can survive for long periods without a food source. Penicillin-binding proteins (PBPs) mean E. faecalis is naturally resistant to penicillin, which when prescribed inhibits E. faecalis activity, but does not kill the bacteria.
E. faecalis requires folic acid to grow, and does not absorb it from their environment so much produce their own. Any medications that interfere with the production of folic acid can kill these bacterial infections, but E. faecalis can absorb folic acid from the body, so this medication doesn’t really work.
E. faecalis alters host response, which means the bacteria changes the way the cells it lives on behave, to facilitate its own survival. It suppresses the action of lymphocytes, your infection-fighting white blood cells. The bacteria produce enzymes that are toxic to cells. E. faecalis is thought to be responsible for 80 per cent of human infections, usually when the bacteria enters a wound, the bloodstream, or urine. Extra susceptible people include those with impaired immunity.
About E. faecalis
E. Faecalis is a gram-positive bacteria, considered a non-motile microbe – that is, it doesn’t spontaneously move around using energy to do so, but is transported. This bacterium ferments glucose without producing gas, and is considered a facultative bacteria – that means it is adaptive to its circumstances.
The harsh conditions in which E. faecalis can survive include extremely alkaline conditions (up to a pH of 9.6) and high salt concentrations. It is resistant to bile salts, detergents, heavy metals, ethanol and extreme dryness (desiccation). Temperature ranges include 10-45 °C, with temperatures of up to 60°C survivable for up to half an hour.
E. faecalis was known as Streptococcus faecalis until 1984.
E. faecalis is known to have antibiotic resistance to
- Penicillins (nafcillin, oxacillin, trimethoprim-sulfamethoxazole)
- More commonly, vancomycin
Antibiotic treatment options for E. faecalis include:
- Nitrofurantoin (for uncomplicated UTIs)
- Ampicillin if bacteria are susceptible
- Quinupristin/dalfopristin for E. faecium, but not E. faecalis
- NaOCI and chlorhexidine (CHX) in root canals, though this wasn’t very effective in recent studies
How do people catch E. faecalis?
E. faecalis can’t move around by itself, so it is transmitted ‘by hand’. That is, E. faecalis is found in faecal matter (bowel motions and the anal area), so if the anus isn’t cleaned properly or contact is had with animal or human faeces (like not washing hands properly after the toilet, messy sex, etc.) the bacteria can be transmitted from person to person.
Doorknobs, telephones, towels and soap can contain E. faecalis, but just because you touch a bacteria does not mean you will get infected – this comes down directly to your own defences being strong.
Studies into vulvovaginal E. faecalis infections/presence
One study looked into the incidence of E. faecalis in vaginal secretions, and how that correlated with antibiotic use for previous vaginal and other infections, finding that there was a far greater chance of the presence of E. faecalis in women who had been recently treated with antibiotics. The study involved 300 fertile-aged women, 282 of them married. The women were put into four groups of 75 women in each group:
- Women who had not been treated with antibiotics in the previous six months
- Women who had been treated for genital tract infections with antibiotics in the past six months
- Women who were treated for nonspecific vaginitis in the previous six months with antibiotics
- Women who were treated with antibiotics in the previous six months for a non-vaginal infection
- E. faecalis was found in 112 of the 300 patients
- 13 patients in the first group of women who had not been treated with antibiotics in the previous six months (17 per cent)
- 26 patients in the second group, who had been treated with antibiotics for a vaginal infection in the previous six months (35 per cent)
- 39 patients in the third group, who had been treated with antibiotics for nonspecific vaginitis over the previous six months (52 per cent)
- 34 patients in the fourth group, who were treated with antibiotics for a non-pelvic infection (45 per cent)
- Overall, E. faecalis was found in 17 per cent of patients who had not had antibiotics in the past six months, but in 44 per cent who had.
Another study looked at the pH variations when E. faecalis was present, and the incidence of bacterial vaginosis. The study looked at 90 women, with 24 per cent returning a positive test result for E. faecalis, however out of those with signs of bacterial vaginosis, it was found 53 per cent of the time.
E. faecalis was most often associated with the presence of signs of bacterial vaginosis. When only two signs of bacterial vaginosis were present (pH of more than 4.0 and changed vaginal discharge colour), E. faecalis was present in 60 per cent of cases.
The researchers concluded that pH change in the vagina was associated with E. faecalis in bacterial vaginosis, but was not a sure sign of the presence of E. faecalis.
A further study looked into interactions between urinary tract infection pathogens (Escherichia coli and Enterococcus faecalis) and bacterial vaginosis pathogen, Gardnerella vaginalis, using biofilm models in vitro. Results showed that dual-species biofilms reached significantly higher bacterial concentrations than a single species biofilm.
All the urogenital pathogens coexisted with G. vaginalis, with the conclusion being that uropathogens can incorporate into mature BV biofilms.