Microbiological Characteristics of Biofilm on Double J Ureteral Stents After Lithotripsy.

Microbiological Characteristics of Biofilm on Double J Ureteral Stents After Lithotripsy: A Randomized Controlled Trial

Indwelling Double J (DJ) ureteral stents are commonly used following lithotripsy to ensure adequate urinary drainage and prevent obstruction. However, stent-related biofilm formation remains a significant clinical problem, contributing to infection, encrustation, patient discomfort, and stent failure. Biofilms consist of microbial communities embedded within an extracellular polymeric substance (EPS), which protects microorganisms from host defenses and antimicrobial agents.

Antibiotic therapy alone may be insufficient to eradicate established biofilms due to poor penetration into the EPS matrix. Linezolid is a potent antibiotic with activity against gram-positive organisms commonly implicated in urinary tract colonization and penetrate and effectively act against bacterial biofilms. Mucolytic agents, by disrupting the biofilm matrix, may enhance antimicrobial penetration and reduce biofilm burden.

The combination of an antibiotic with a mucolytic agent may therefore provide superior biofilm reduction compared to either approach alone or no treatment.

Study Overview

• Status: Not yet recruiting
• Conditions: Double J Stent
• Intervention / Treatment: Drug: Linezolid (LZD); Drug: N-Acetyl Cysteine (NAC)

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: Ammar Alorabi; Phone Number: +201067608011; Email: ammar.alorabi95@gmail.com

Study Locations

• Egypt
  • Menoufia
    • Shebin El-Kom, Menoufia, Egypt, 32511
      • Menoufia Faculty of Medicine
      • Contact: Mohamed Aziz; Phone Number: +201023321949; Email: Mohammed_aziz2006@yahoo.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria

• Adult patients (≥18 years).
• Undergoing lithotripsy (FURS, URS or PCNL) with DJ stent insertion.
• Stone free status.
• Planned stent indwelling time of 1 month.
• Negative preoperative urine culture.

Exclusion Criteria

• Known allergy or contraindication to linezolid or the selected mucolytic agent.
• Chronic kidney disease.
• Immunocompromised patients (e.g., chemotherapy, long-term steroid use).
• Pregnant or lactating women.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Control group; Patients of this group will receive no medications
Active Comparator: Antibiotic group; Patients of this group will receive Linezolid.	Drug: Linezolid (LZD); Linezolid 600 mg, oral, twice daily, for 7 days.
Active Comparator: Mucolytic group; Patients of this group will receive N-Acetylcysteine.	Drug: N-Acetyl Cysteine (NAC); N-Acetyl cysteine 600 mg, oral, once daily, for 30 days.
Active Comparator: Combination group; Patients of this group will receive both Linezolid and N-Acetylcysteine.	Drug: Linezolid (LZD); Linezolid 600 mg, oral, twice daily, for 7 days.; Drug: N-Acetyl Cysteine (NAC); N-Acetyl cysteine 600 mg, oral, once daily, for 30 days.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Biofilm bacterial load	Biofilm bacterial load, defined as the quantity of bacteria within a biofilm, measured by culture of a swab taken off Double J stent after removal and expressed in numbers.	1 month

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Urinary tract infection rate	urinary tract infection, defined as presence of positive urine culture after double J stent insertion, expressed in numbers.	1 month
Double J related symptoms	Double J related symptoms, defined as lower urinary tract symptoms that patient expeirence after double J stent insertion, measured using the ureteral stent symptom questionnaire (USSQ), expressed in numbers.	1 month

Collaborators and Investigators

• Sponsor: Menoufia University

Study record dates

Study Major Dates

• Study Start (Estimated): January 1, 2026
• Primary Completion (Estimated): June 1, 2026
• Study Completion (Estimated): July 1, 2026

Study Registration Dates

• First Submitted: December 22, 2025
• First Submitted That Met QC Criteria: December 22, 2025
• First Posted (Actual): December 24, 2025

Study Record Updates

• Last Update Posted (Actual): December 24, 2025
• Last Update Submitted That Met QC Criteria: December 22, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Biofilm; Linezolid; Mucolytic; ureteric stent; Double J stent; DJ stent
• Additional Relevant MeSH Terms: Amino Acids, Peptides, and Proteins; Sulfur Compounds; Organic Chemicals; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Azoles; Acids, Acyclic; Carboxylic Acids; Amides; Amino Acids; Acetamides; Acetates; Oxazolidinones; Oxazoles; Cysteine; Amino Acids, Sulfur; Linezolid; Acetylcysteine
• Other Study ID Numbers: Biofilm of DJ stent

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: Yes