C. parapsilosis
Emery Haley, PhD, Scientific Writing Specialist
Candida parapsilosis
Clinical Summary
- C. parapsilosis is recognized as a classical, biofilm-forming, yeast uropathogen.
- C. parapsilosis is associated with complicated UTI.
- In symptomatic UTI patients, C. parapsilosis:
- 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 C. parapsilosis UTI include pyelonephritis, candidemia, and urosepsis.
Yeast Characteristics
Growth Requirements
A Yeast (slow growth, prefers yeast extract peptone dextrose medium and acidic pH)
Biofilm Formation
Yes
Nitrate Reduction
No
Pathogenicity
Colonizer or Pathobiont
Clinical Relevance in UTI
UTIs can be caused by yeasts and Candida yeast species are classically recognized as uropathogens.[1–4]
Unlike common bacterial uropathogens, yeasts do not display nitrate reductase activity, so screening strategies involving urinalysis for nitrite positivity will be false-negative.[5,6]
C. parapsilosis is primarily seen in complicated UTIs among high-risk patient populations such as young children, individuals with abnormalities of the urinary tract and/or indwelling catheters, adults with immunocompromising comorbidities including diabetes mellitus, and hospitalized patients admitted to intensive care units.[7–9]
In a study of older adult males and females with clinically suspected complicated UTI, C. parapsilosis 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.[10] Furthermore, elevated markers of immune system activation in the urinary tract have been measured from the same clinical urine specimens in which C. parapsilosis was detected, indicating that the presence of C. parapsilosis was associated with an immune response to urinary tract infection.[11–13]
Severe complications of C. parapsilosis UTI, including pyelonephritis, candidemia, and urosepsis, have been reported.[14,15]
Together, these findings indicate that C. parapsilosis should be seriously considered as a uropathogen and demonstrate the value of detecting this organism, particularly in individuals with immune compromise, urinary tract abnormalities, or other risk factors for complicated UTI.
Treatment
Clinically recommended antifungal agents for the treatment of C. parapsilosis UTIs are Fluconazole (PO/IV) or Flucytosine (PO).[16] Note that other antifungal agents do not reach therapeutic concentrations in the urine.
1. Fisher, J.F.; Kavanagh, K.; Sobel, J.D.; Kauffman, C.A.; Newman, C.A. Candida Urinary Tract Infection: Pathogenesis. Clin. Infect. Dis. 2011, 52, S437–S451, doi:10.1093/cid/cir110.
2. Kauffman, C.A.; Fisher, J.F.; Sobel, J.D.; Newman, C.A. Candida Urinary Tract Infections—Diagnosis. Clin. Infect. Dis. 2011, 52, S452–S456, doi:10.1093/cid/cir111.
3. Sobel, J.D.; Fisher, J.F.; Kauffman, C.A.; Newman, C.A. Candida Urinary Tract Infections—Epidemiology. Clin. Infect. Dis. 2011, 52, S433–S436, doi:10.1093/cid/cir109.
4. Fisher, J.F.; Sobel, J.D.; Kauffman, C.A.; Newman, C.A. Candida Urinary Tract Infections—Treatment. Clin Infect Dis 2011, 52, S457–S466, doi:10.1093/cid/cir112.
5. BacDive | The Bacterial Diversity Metadatabase Available online: https://bacdive.dsmz.de/ (accessed on 11 February 2025).
6. BioCyc Pathway/Genome Database Collection Available online: https://biocyc.org/ (accessed on 11 February 2025).
7. Odabasi, Z.; Mert, A. Candida Urinary Tract Infections in Adults. World J Urol 2020, 38, 2699–2707, doi:10.1007/s00345-019-02991-5.
8. Talapko, J.; Meštrović, T.; Škrlec, I. Growing Importance of Urogenital Candidiasis in Individuals with Diabetes: A Narrative Review. World J. Diabetes 2022, 13, 809–821, doi:10.4239/wjd.v13.i10.809.
9. Ekinci, F.; Yildizdas, D.; Horoz, O.O.; Gundeslioglu, O.O.; Alabaz, D. Treatment of Candida Urinary Tract Infections with Micafungin in Children. Pediatr. Int. 2022, 64, e15033, doi:10.1111/ped.15033.
10. 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.
11. 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.
12. 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.
13. 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.
14. Elbaz, M.; Chikly, A.; Meilik, R.; Ben-Ami, R. Frequency and Clinical Features of Candida Bloodstream Infection Originating in the Urinary Tract. J. Fungi 2022, 8, 123, doi:10.3390/jof8020123.
15. Radinasoa, R.P.; Andrianiaina, A.M.; Randriamamizoly, H.; Andrianarivony, L.F.A.; Randriamarotia, H.W.F.; Vololontiana, H.M.D. Acute Obstructive Fungus Ball Pyelonephritis with Candida Parapsilosis: A Case Report. Clin. Case Rep. 2023, 11, e7484, doi:10.1002/ccr3.7484.
16. Pappas, P.G.; Kauffman, C.A.; Andes, D.R.; Clancy, C.J.; Marr, K.A.; Ostrosky-Zeichner, L.; Reboli, A.C.; Schuster, M.G.; Vazquez, J.A.; Walsh, T.J.; et al. Clinical Practice Guideline for the Management of Candidiasis: 2016 Update by the Infectious Diseases Society of America. Clin Infect Dis 2016, 62, e1–e50, doi:10.1093/cid/civ933.
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.