Is Enterococcus faecalis (E. faecalis) in the vagina normal?

Enterococcus faecalis in the Vagina: Clinical Significance and Management

Enterococcus faecalis can be present in the vagina and may be considered normal flora in some women, but its presence in high numbers is often associated with aerobic vaginitis, especially when accompanied by vaginal pH >4.5 and inflammatory symptoms.

Normal Vaginal Flora vs. Aerobic Vaginitis

E. faecalis is not typically considered part of the dominant healthy vaginal microbiome, which is primarily composed of Lactobacillus species. However, its presence doesn't always indicate pathology:

• Normal vaginal flora is characterized by:

  • Predominance of Lactobacillus species
  • Vaginal pH ≤4.5
  • Minimal discharge and no odor 1

• Aerobic vaginitis (AV) is characterized by:

  • Presence of aerobic pathogens including E. faecalis (the most frequently isolated AV pathogen in about 31% of cases)
  • Vaginal pH >4.5
  • Inflammatory symptoms
  • Decreased lactobacilli 2

Clinical Significance of E. faecalis in the Vagina

The presence of E. faecalis in the vagina may be clinically significant in several contexts:

• After antibiotic use: Studies show significantly higher rates of E. faecalis colonization in women who have received antibiotic treatment (44%) compared to those who haven't (17.33%) 3

• Aerobic vaginitis: E. faecalis is found in 52.78% of women with signs of bacterial vaginosis/aerobic vaginitis compared to 24.05% in women with normal pH 4

• Potential protective effects: Interestingly, some strains of E. faecalis may produce anti-inflammatory compounds (tetramic acids) that can inhibit inflammatory responses to other pathogens 5

• Potential risks: E. faecalis in aerobic vaginitis has been associated with:

  • Increased risk of sexually transmitted infections
  • Possible association with HPV persistence and cervical lesions 2

Diagnostic Approach

When E. faecalis is identified in vaginal cultures, consider:

1. Measure vaginal pH:

   • pH >4.5 suggests bacterial vaginosis or aerobic vaginitis
   • pH ≤4.5 suggests normal flora or candidiasis 1

2. Evaluate for symptoms:

   • Discharge characteristics (homogeneous, white, thin in AV)
   • Presence of odor
   • Inflammation or irritation 1

3. Consider other clinical signs:

   • The combination of pH >4.0, changed color of vaginal secretions, and positive amino odor test is associated with E. faecalis in 60.78% of cases 4

Management Recommendations

If E. faecalis is found in the context of aerobic vaginitis with symptoms:

1. Antimicrobial therapy:

   • For symptomatic aerobic vaginitis, treatment should be based on microscopic or microbiological findings 2
   • The CDC and American College of Obstetricians and Gynecologists recommend standard antibiotic treatment for bacterial vaginosis, with metronidazole 500mg orally twice daily for 7 days as first-line treatment 1
   • For E. faecalis specifically, antimicrobial selection should be guided by susceptibility testing; options include ampicillin, piperacillin-tazobactam, and vancomycin 6

2. Adjunctive therapies:

   • Topical steroids to reduce inflammation
   • Estrogen for atrophy if present
   • Probiotic therapy may be considered as an adjunct treatment 1, 2

3. Follow-up:

   • Follow-up visits are generally not needed unless symptoms persist or recur 1
   • For pregnant women, a follow-up evaluation one month after treatment completion is recommended 1

Special Considerations

• Pregnancy: Untreated bacterial vaginosis or aerobic vaginitis increases risks of preterm birth, premature rupture of membranes, and postpartum endometritis 1

• Recurrent infections: Consider daily lukewarm baths and mild antiseptic baths 2-3 times weekly using chlorhexidine, octenidine, or polyhexanide 1

• Sexual partners: Patients should abstain from sexual intercourse until treatment is completed and symptoms resolve 1

Pitfalls and Caveats

• Overtreatment risk: Not all E. faecalis colonization requires treatment, especially in asymptomatic women with normal pH

• Diagnostic challenges: Vaginal pH >4.5 is associated with E. faecalis but is not a definitive indicator; microbiological examination is necessary for confirmation 4

• Medication interactions: Patients using metronidazole should avoid alcohol during treatment and for 24 hours after; clindamycin cream can weaken latex condoms and diaphragms 1