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E. faecalis

Emery Haley, PhD, Scientific Writing Specialist

Enterococcus faecalis

Clinical Summary

  • E. faecalis is recognized as a classical, gram-positive, biofilm-forming, nitrite-negative uropathogen.
  • E. faecalis is primarily associated with all types of UTIs, from acute uncomplicated cystitis to complicated, catheter-associated, and hospital-acquired UTIs with life-threatening complications.
  • In symptomatic UTI patients, E. faecalis:
    • Is not a contaminant (is found in catheter-collected urine specimens).
    • Is viable (can grow out on culture).
    • Is pathogenic (associated with elevated urine biomarkers of infection).
  • Reported severe complications of E. faecalis UTI include pyelonephritis, bacteremia, infective endocarditis, urosepsis, and death.

Bacterial Characteristics

Gram-stain

Gram-positive

Morphology

Coccus

Growth Requirements

Non-fastidious (grows moderately well in standard urine culture conditions)
Facultative anaerobe/microaerophile

Nitrate Reduction

No

Urease

Negative

Biofilm Formation

Yes

Pathogenicity

Colonizer or Pathobiont

Clinical Relevance in UTI

E. faecalis is a gram-positive, biofilm-forming microorganism classically recognized as a uropathogen. E. faecalis is among the most common bacterial pathogens responsible for UTIs and is the most common gram-positive uropathogen. However, E. faecalis lacks nitrate reductase activity, so screening strategies involving urinalysis for nitrite positivity will be false-negative.[1,2] Critically, studies with enhanced urine culture techniques or molecular techniques demonstrate that, despite its non-fastidious nature, E. faecalis frequently goes undetected by standard diagnostic urine culture.[3,4]

E. faecalis is associated with all types of UTIs, from acute uncomplicated cystitis to complicated, catheter-associated, and hospital-acquired UTIs with life-threatening complications, in adults and children.[5,6] The prevalence of E. faecalis is reportedly higher among men than women. [7,8] Risk factors for complicated UTI, including older age, immunocompromise, multimorbidity, hospitalization, use of an indwelling urinary catheter, and urinary tract abnormalities, are also associated with a higher prevalence of E. faecalis UTI.[7,9–12] E. faecalis has also been found within urinary tract epithelial cells of patients with chronic lower urinary tract symptoms.[13] Such an ability to form intracellular bacterial reservoirs is associated with persistent and recurrent UTIs.[6,13–15]

E. faecalis is known for facilitating hard-to-treat polymicrobial infections involving multidrug resistance and biofilms.[5,16,17] In preclinical studies of polymicrobial UTI models, E. faecalis exhibited synergism with E. coli, M. morganii, P. mirabilis, and P. aeruginosa but antagonism with C. albicans, Klebsiella species, and P. stuartii.[5,18]

In a study of older adult males and females with clinically suspected complicated UTI, E. faecalis was detected in both midstream voided and in-and-out-catheter collected specimens indicating that it was truly present in the bladder, not simply a contaminant picked up during voiding.[19] Furthermore, elevated markers of immune system activation in the urinary tract have been measured from the same clinical urine specimens in which E. faecalis was detected, indicating that the presence of E. faecalis was associated with an immune response to urinary tract infection.[20–22]

Severe reported complications of E. faecalis UTI include pyelonephritis, bacteremia, infective endocarditis, urosepsis, and death.[12,23,24] Together, these findings indicate that E. faecalis should be seriously considered as a uropathogen and demonstrate the value of detecting this organism in any individual with symptoms of UTI.

Treatment

Evidence of Efficacy (Checkmarks): Ciprofloxacin, Doxycycline, Fosfomycin, Levofloxacin, Linezolid, Nitrofurantoin, and Vancomycin.

References

1. BacDive | The Bacterial Diversity Metadatabase Available online: https://bacdive.dsmz.de/ (accessed on 11 February 2025).
2. BioCyc Pathway/Genome Database Collection Available online: https://biocyc.org/ (accessed on 11 February 2025).
3. Hochstedler, B.R.; Burnett, L.; Price, T.K.; Jung, C.; Wolfe, A.J.; Brubaker, L. Urinary Microbiota of Women with Recurrent Urinary Tract Infection: Collection and Culture Methods. Int Urogynecol J 2021, 1–8, doi:10.1007/s00192-021-04780-4.
4. Festa, R.A.; Luke, N.; Mathur, M.; Parnell, L.; Wang, D.; Zhao, X.; Magallon, J.; Remedios-Chan, M.; Nguyen, J.; Cho, T.; et al. A Test Combining Multiplex-PCR with Pooled Antibiotic Susceptibility Testing Has High Correlation with Expanded Urine Culture for Detection of Live Bacteria in Urine Samples of Suspected UTI Patients. Diagn Microbiol Infect Dis 2023, 107, 116015, doi:10.1016/j.diagmicrobio.2023.116015.
5. Gaston, J.R.; Johnson, A.O.; Bair, K.L.; White, A.N.; Armbruster, C.E. Polymicrobial Interactions in the Urinary Tract: Is the Enemy of My Enemy My Friend? Infect Immun 2021, 89, doi:10.1128/iai.00652-20.
6. Yoo, J.-J.; Shin, H.B.; Song, J.S.; Kim, M.; Yun, J.; Kim, Z.; Lee, Y.M.; Lee, S.W.; Lee, K.W.; Kim, W.B.; et al. Urinary Microbiome Characteristics in Female Patients with Acute Uncomplicated Cystitis and Recurrent Cystitis. J. Clin. Med. 2021, 10, 1097, doi:10.3390/jcm10051097.
7. Turjeman, A.; Babich, T.; Pujol, M.; Carratalà, J.; Shaw, E.; Gomila-Grange, A.; Vuong, C.; Addy, I.; Wiegand, I.; Grier, S.; et al. Risk Factors for Enterococcal Urinary Tract Infections: A Multinational, Retrospective Cohort Study. Eur. J. Clin. Microbiol. Infect. Dis. 2021, 40, 2005–2010, doi:10.1007/s10096-021-04207-4.
8. Salm, J.; Salm, F.; Arendarski, P.; Kramer, T.S. High Frequency of Enterococcus Faecalis Detected in Urinary Tract Infections in Male Outpatients – a Retrospective, Multicenter Analysis, Germany 2015 to 2020. BMC Infect. Dis. 2023, 23, 812, doi:10.1186/s12879-023-08824-6.
9. Tanaka, Y.; Oishi, T.; Ono, S.; Kono, M.; Kato, A.; Miyata, I.; Ohno, N.; Ouchi, K. Epidemiology of Urinary Tract Infections in Children: Causative Bacteria and Antimicrobial Therapy. Pediatr. Int. 2021, 63, 1198–1204, doi:10.1111/ped.14639.
10. Tien, B.Y.Q.; Goh, H.M.S.; Chong, K.K.L.; Bhaduri-Tagore, S.; Holec, S.; Dress, R.; Ginhoux, F.; Ingersoll, M.A.; Williams, R.B.H.; Kline, K.A. Enterococcus Faecalis Promotes Innate Immune Suppression and Polymicrobial Catheter-Associated Urinary Tract Infection. Infect. Immun. 2017, 85, doi:10.1128/iai.00378-17.
11. Johnson, A.O.; Shipman, B.M.; Hunt, B.C.; Learman, B.S.; Brauer, A.L.; Zhou, S.P.; Blair, R.H.; Nisco, N.J.D.; Armbruster, C.E. Function and Contribution of Two Putative Enterococcus Faecalis Glycosaminoglycan Degrading Enzymes to Bacteremia and Catheter-Associated Urinary Tract Infection. Infect. Immun. 2024, 92, e00199-24, doi:10.1128/iai.00199-24.
12. Parente, G.; Gargano, T.; Pavia, S.; Cordola, C.; Vastano, M.; Baccelli, F.; Gallotta, G.; Bruni, L.; Corvaglia, A.; Lima, M. Pyelonephritis in Pediatric Uropathic Patients: Differences from Community-Acquired Ones and Therapeutic Protocol Considerations. A 10-Year Single-Center Retrospective Study. Children 2021, 8, 436, doi:10.3390/children8060436.
13. Horsley, H.; Malone-Lee, J.; Holland, D.; Tuz, M.; Hibbert, A.; Kelsey, M.; Kupelian, A.; Rohn, J.L. Enterococcus Faecalis Subverts and Invades the Host Urothelium in Patients with Chronic Urinary Tract Infection. PLoS ONE 2013, 8, e83637, doi:10.1371/journal.pone.0083637.
14. Sansone, S.; Ramos, Y.; Segal, S.; Asfaw, T.S.; Morales, D.K. Uncovering Surface Penetration by Enterococci From Urinary Tract Infection Patients. Urogynecology 2024, 30, 320–329, doi:10.1097/spv.0000000000001476.
15. Chieng, C.C.Y.; Kong, Q.; Liou, N.S.Y.; Khasriya, R.; Horsley, H. The Clinical Implications of Bacterial Pathogenesis and Mucosal Immunity in Chronic Urinary Tract Infection. Mucosal Immunol. 2023, 16, 61–71, doi:10.1016/j.mucimm.2022.12.003.
16. Xu, W.; Fang, Y.; Zhu, K. Enterococci Facilitate Polymicrobial Infections. Trends Microbiol. 2024, 32, 162–177, doi:10.1016/j.tim.2023.07.010.
17. Kao, P.H.-N.; Ch’ng, J.-H.; Chong, K.K.L.; Stocks, C.J.; Wong, S.L.; Kline, K.A. Enterococcus Faecalis Suppresses Staphylococcus Aureus-Induced NETosis and Promotes Bacterial Survival in Polymicrobial Infections. FEMS Microbes 2023, 4, xtad019, doi:10.1093/femsmc/xtad019.
18. Abell-King, C.; Pokhrel, A.; Rice, S.A.; Duggin, I.G.; Söderström, B. Multispecies Bacterial Invasion of Human Host Cells. Pathog. Dis. 2024, 82, ftae012, doi:10.1093/femspd/ftae012.
19. Wang, D.; Haley, E.; Luke, N.; Mathur, M.; Festa, R.; Zhao, X.; Anderson, L.A.; Allison, J.L.; Stebbins, K.L.; Diaz, M.J.; et al. Emerging and Fastidious Uropathogens Were Detected by M-PCR with Similar Prevalence and Cell Density in Catheter and Midstream Voided Urine Indicating the Importance of These Microbes in Causing UTIs. Infect. Drug Resist. 2023, Volume 16, 7775–7795, doi:10.2147/idr.s429990.
20. Haley, E.; Luke, N.; Mathur, M.; Festa, R.A.; Wang, J.; Jiang, Y.; Anderson, L.A.; Baunoch, D. The Prevalence and Association of Different Uropathogens Detected by M-PCR with Infection-Associated Urine Biomarkers in Urinary Tract Infections. Res. Rep. Urol. 2024, 16, 19–29, doi:10.2147/rru.s443361.
21. Akhlaghpour, M.; Haley, E.; Parnell, L.; Luke, N.; Mathur, M.; Festa, R.A.; Percaccio, M.; Magallon, J.; Remedios-Chan, M.; Rosas, A.; et al. Urine Biomarkers Individually and as a Consensus Model Show High Sensitivity and Specificity for Detecting UTIs. BMC Infect Dis 2024, 24, 153, doi:10.1186/s12879-024-09044-2.
22. Parnell, L.K.D.; Luke, N.; Mathur, M.; Festa, R.A.; Haley, E.; Wang, J.; Jiang, Y.; Anderson, L.; Baunoch, D. Elevated UTI Biomarkers in Symptomatic Patients with Urine Microbial Densities of 10,000 CFU/ML Indicate a Lower Threshold for Diagnosing UTIs. MDPI 2023, 13, 1–15, doi:10.3390/diagnostics13162688.
23. Wu, Y.; Li, P.; Huang, Z.; Liu, J.; Yang, B.; Zhou, W.; Duan, F.; Wang, G.; Li, J. Four-Year Variation in Pathogen Distribution and Antimicrobial Susceptibility of Urosepsis: A Single-Center Retrospective Analysis. Ther. Adv. Infect. Dis. 2024, 11, 20499361241248056, doi:10.1177/20499361241248058.
24. Tellapragada, C.; Östlund, H.; Giske, C.; Rasmussen, M.; Berge, A. Recurrent Bacteremia with Enterococcus Faecalis, the Clinical Findings Predicting Endocarditis, and Genomic Characterization of the Isolates: A Retrospective Cohort Study. Eur. J. Clin. Microbiol. Infect. Dis. 2023, 42, 1001–1009, doi:10.1007/s10096-023-04636-3.

About the Author

Dr. Emery Haley is a scientific writing specialist with over ten years of experience in translational cell and molecular biology. As both a former laboratory scientist and an experienced science communicator, Dr. Haley is passionate about making complex research clear, approachable, and relevant. Their work has been published in over 10 papers and focuses on bridging the gap between the lab and real-world patient care to help drive better health outcomes.

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