Effect of co-trimoxazole and N-acetylcysteine alone and in combination on bacterial adherence on ureteral stent surface.

To assess the effect of co-trimoxazole and N-acetylcysteine (NAC), alone and in combination, on bacterial adherence to biofilm formed on ureteral stent surfaces. This prospective randomized study was conducted on 636 patients who underwent double J ureteral stent insertion after variable urological procedures. Patients were randomized into four groups: A (n = 165), no antibiotics or mucolytics during stent indwelling; B (n = 153), oral NAC (200 mg/day for children aged < 12 years old and 600 mg/day for adults) during stent indwelling; C (n = 162), oral co-trimoxazole (2 mg TMP/kg/day) during stent indwelling; and D (n = 156), both oral NAC and co-trimoxazole during stent indwelling. Two weeks following double J stent (JJ stent) insertion, urinalysis was performed on all patients and urine culture was done for all the patients at the day of double J stent removal. The stent was removed 2 weeks postoperatively, and a stent segment sized 3-5 cm from the bladder segment of the stent was sent for culture. Positive stent cultures were found in 63.6% (105/165), 43.1% (66/153), 37% (60/162), and 19.2% (30/156) patients of groups A, B, C, and D, respectively. E. coli was the organism most commonly isolated from the stent culture in all groups. The combination of co-trimoxazole and NAC was more effective in reducing bacterial adherence on ureteral stent surfaces than either alone.

Ureteral Stents Harbor Complex Biofilms With Rich Microbiome-Metabolite Interactions.

PURPOSE: We sought to determine microbe-metabolite composition and interactions within indwelling ureteral stent biofilms, determine their association with patient factors including infection, and reconstitute biofilm formation on relevant surface materials in vitro. MATERIALS AND METHODS: Upon ureteral stent removal from patients, proximal and distal ends were swabbed. Samples were analyzed by 16S next-generation sequencing and metabolomics. A continuous-flow stir-tank bioreactor was used to reconstitute and quantify in vitro biofilm formation from stent-isolated bacteria on stent-related materials including silicone, polytetrafluoroethylene, polyurethane, polycarbonate, and titanium. Diversity, relative abundance, and association with clinical factors were analyzed with ANOVA and Bonferroni t-tests or PERMANOVA. Biofilm deposition by microbial strain and device material type were analyzed using plate counts and scanning electron microscopy following bioreactor incubation. RESULTS: All 73 samples from 37 ureteral stents harbored microbiota. Specific genera were more abundant in samples from stents wherein there was antibiotic exposure during indwelling time (Escherichia/Shigella, Pseudomonas, Staphylococcus, Ureaplasma) and in those associated with infection (Escherichia/Shigella, Ureaplasma). The enriched interaction subnetwork in stent-associated infection included Ureaplasma and metabolite 9-methyl-7-bromoeudistomin. Strains identified as clinically relevant and central to interaction networks all reconstituted biofilm in vitro, with differential formation by strain (Enterococcus faecalis most) and material type (titanium least). CONCLUSIONS: Ureteral stent biofilms exhibit patterns unique to stent-associated infection and antibiotic exposure during indwelling time. Microbes isolated from stents reconstituted biofilm formation in vitro. This work provides a platform to test novel materials, evaluate new coatings for anti-biofilm properties, and explore commensal strain use for bacterial interference against pathogens.

Processing human urine and ureteral stents for 16S rRNA amplicon sequencing.

Ureteral stents are commonly used medical devices that harbor a unique and patient-specific microbial community. This protocol describes an optimized procedure for high-quality DNA extraction from both urine and ureteral stent samples for the purpose of downstream microbiota characterization by amplicon sequencing. Detailed instruction is provided for 16S rRNA gene V4 region sequencing with the Illumina platform, which enables accurate and reproducible microbiota profiling of low bacterial abundance urine and stent samples. For complete details on the use and execution of this protocol, please refer to Al et al. (2020).

Xanthogranulomatous Ureteritis Mimicking Ureteral Involvement by Cancer in a Radical Cystectomy Specimen.

Xanthogranulomatous pyelonephritis is well established as a renal mass-forming inflammatory process. However, a ureteral counterpart is minimally recognized. In this article, we present a case of xanthogranulomatous ureteritis in an 81-year-old woman, mimicking ureteral involvement by cancer in a radical cystectomy specimen for invasive urothelial carcinoma. Similar to the pathogenesis of xanthogranulomatous pyelonephritis, the patient was noted to have ureteral obstruction by calculus and had urine culture positive for Klebsiella pneumoniae. To our knowledge, this is the first report of xanthogranulomatous ureteritis associated with this pathogen and the only report associated with concurrent bladder cancer. Increased pathologist and urologist awareness of xanthogranulomatous ureteritis expands the spectrum of pseudotumoral processes of the ureter.

Risk of Urinary Tract Infection Symptoms after Posthysterectomy Cystoscopy with 50% Dextrose as Compared with Saline Cystoscopy with Indigo Carmine.

STUDY OBJECTIVE: Compare odds of postoperative urinary symptoms in women who had cystoscopy after benign laparoscopic hysterectomy with 50% dextrose and with normal saline solution with intravenous indigo carmine. DESIGN: Retrospective cohort study. SETTING: Two tertiary care centers. PATIENTS: All women who underwent benign laparoscopic hysterectomy and intraoperative cystoscopy carried out by a single surgeon. INTERVENTIONS: We compared postoperative urinary symptoms in patients who received 50% dextrose cystoscopy fluid (January 2016-June 2017) with those who received saline cystoscopy with intravenous indigo carmine (November 2013-April 2014). MEASUREMENTS AND MAIN RESULTS: A total of 96 patients had cystoscopy with 50% dextrose and 104 with normal saline with intravenous indigo carmine. Differences in baseline characteristics of the two groups of participants mainly reflected institutional population diversity: age (45.2 vs 41.9, p = .01), body mass index (26.9 vs 33.4, p <.01), race, current smoking status (1% vs 7.8%, p = .04), diabetes (2.1% vs 11.5%, p = .01), history of abdominal surgery (53.1% vs 74%, p <.01), hysterectomy type, receipt of intraoperative antibiotics (92.7% vs 100%, p <.01), recatheterization (10.4% vs 0%, p <.01), and removal of catheter on postoperative day 0 (66.7% vs 12.5%, p <.01). Urinary symptoms were similar for 50% dextrose and saline (12.5% vs 7.7%, p = .19). After adjusting for age, body mass index, race, diabetes, and day of catheter removal, there remained no significant differences in urinary symptoms between the groups (odds ratio 3.19 [95% confidence interval, 0.82-12.35], p = .09). One immediate bladder injury was detected in the saline group and 1 delayed lower urinary tract injury in the 50% dextrose group. CONCLUSION: Overall, most women experienced no urinary symptoms after benign laparoscopic hysterectomy. There were no significant differences in postoperative urinary symptoms or empiric treatment of urinary tract infection after the use of 50% dextrose cystoscopy fluid as compared with normal saline. The previous finding of increased odds of urinary tract infection after dextrose cystoscopy may be due to use in a high-risk population.

Surface analysis of ureteral stent before and after implantation in the bodies of child patients.

The aim of this work was to determine which part of a double-J ureteral stent (DJ stents) showed the highest tendency to crystal, calculi, and biofilm deposition after ureterorenoscopic-lithotripsy procedure (URS-L) to treat calcium oxalate stones. Additionally, the mechanical strength and the stiffness of DJ stents were evaluated before and after exposure to urine. Obtained results indicated that the proximal (renal pelvis) and distal (urinary bladder) part is the most susceptible for post-URS-L fragments and urea salt deposition. Both, the outer and inner surfaces of the DJ ureteral stents were completely covered even after 7 days of implantation. Encrustation of DJ stents during a 31-day period results in reducing the Young's modulus by 27-30%, which confirms the loss of DJ stent elasticity and increased probability of cracks or interruption. Performed analysis pointed to the need to use an antibacterial coating in the above-mentioned part of the ureteral stent to prolong its usage time and to prevent urinary tract infection.

Ureteral Stent Encrustation: Epidemiology, Pathophysiology, Management and Current Technology.

PURPOSE: Encrustation is a common phenomenon that can occur following placement of a ureteral stent into the urinary tract, and it can lead to serious complications. The following review addresses the mechanism of encrustation, the management of these stents and the newest technology developed to mitigate this issue. MATERIALS AND METHODS: We performed a comprehensive literature search on stent encrustation including peer-reviewed publications, public product listings, and material on current and future stent technology. RESULTS: The mechanism of encrustation is complex and multifaceted, including dwell time, patient specific risk factors, conditioning film formation, biofilm formation and mineral deposition. Several technological developments in stent materials and coatings may have a role in reducing the risk of stent encrustation. It is important to identify the extent of stent encrustation and plan treatment strategies accordingly. We propose a novel treatment algorithm for the management encrusted ureteral stents. CONCLUSIONS: The ubiquity of ureteral stents in urology practice mandates updated knowledge about the prevention of stent encrustation, identification of high risk patients and preparedness for removal using multimodal techniques.

Ureteral Stent Microbiota Is Associated with Patient Comorbidities but Not Antibiotic Exposure.

Ureteral stents are commonly used to prevent urinary obstruction but can become colonized by bacteria and encrusted, leading to clinical complications. Despite recent discovery and characterization of the healthy urinary microbiota, stent-associated bacteria and their impact on encrustation are largely underexplored. We profile the microbiota of patients with typical short-term stents, as well as over 30 atypical cases (all with paired mid-stream urine) from 241 patients. Indwelling time, age, and various patient comorbidities correlate with alterations to the stent microbiota composition, whereas antibiotic exposure, urinary tract infection (UTI), and stent placement method do not. The stent microbiota most likely originates from adhesion of resident urinary microbes but subsequently diverges to a distinct, reproducible population, thereby negating the urine as a biomarker for stent encrustation or microbiota. Urological practice should reconsider standalone prophylactic antibiotics in favor of tailored therapies based on patient comorbidities in efforts to minimize bacterial burden, encrustation, and complications of ureteral stents.

Dapagliflozin-associated euglycemic diabetic ketoacidosis in a patient with type 2 diabetes mellitus: A case report.

RATIONALE: Rare cases of euglycemic diabetic ketoacidosis (eu-DKA) have been reported after the administration of sodium-glucose cotransporter-2 (SGLT-2) inhibitors. No reports have described eu-DKA complicated by hypernatremia due to SGLT-2 inhibitors. PATIENT CONCERNS: A 76-year-old woman with a 40-year history of type 2 diabetes mellitus (DM), for which metformin (1000 mg/day) and dapagliflozin (10 mg/day) were prescribed, presented with malaise, fever, and oliguria. On presentation, her white blood cell count (11,800/µL), serum creatinine (3.2 mg/dL), and C-reactive protein (54 mg/L) were abnormal. Bilateral pyeloureteritis and diffuse paralytic ileus were present. She received intravenous antibiotics and total parenteral nutrition, and was asked to fast. Her renal function and ileus briefly improved. Oral hypoglycemic agents, metformin and dapagliflozin, along with enteral feeding were reinstituted on day 3 of hospitalization. However, on day 6 of hospitalization, the patient developed an altered state of consciousness including confusion, lethargy, and stupor. Several laboratory abnormalities suggestive of ketoacidosis with euglycemia were noted. DIAGNOSES: The patient was diagnosed with eu-DKA accompanied by severe hypernatremia (corrected serum Na concentration, 163 mEq/L) and hypokalemia following dapagliflozin re-administration. INTERVENTIONS: The patient was treated with indicated intravenous fluid therapy. Dapagliflozin use was discontinued. OUTCOMES: The patient's mental status and laboratory findings improved gradually, and she was discharged on maintenance doses of insulin and metformin on day 14 of hospitalization. LESSONS: Acute illnesses such as diffuse paralytic ileus and urinary tract infection, and dietary restrictions or fasting in patients with DM can be considered potential predisposing factors for SGLT-2 inhibitor-associated eu-DKA. For patients with diabetes in the setting of acute morbidity, timely resumption of the SGLT-2 inhibitor therapy should be carefully determined. In addition, eu-DKA due to SGLT-2 inhibitor use may be accompanied by electrolyte disturbances such as hypernatremia and hypokalemia.

Detection of microbial colonization of the urinary tract of patients prior to secondary ureterorenoscopy is highly variable between different types of assessment: results of a prospective observational study.

This study compares the findings of different detection methods for microorganisms in patients with ureteral stents undergoing secondary ureterorenoscopy including the use of a novel validated examination pipeline for biofilms on ureteral stents. Of the included 94 patients, 21.3% showed bacteriuria in preoperative urine cultures. Intraoperative urine culture showed bacteriuria in four (4.3%) of the patients. Stent biofilm cultures were positive in 12.9% and qPCR detected bacterial DNA in 18.1%. The findings of the different examinations were poorly correlated with each other. Detection of microorganisms in the urinary tract of patients with indwelling ureteral stents is highly dependent on timing (i.e. pre- vs intraoperative) and method of assessment. Preoperative routine urine cultures are not predictive for intraoperative urine- and stent culture. These results cast doubt on the clinical relevance of enterococcal species, staphylococci, and streptococci if identified preoperatively prior to stent removal. The timing of oral preoperative antibiotic prophylaxis might need to be reconsidered.

[Individualized patient care with urological implants using biofilm-resistant surface concepts]. / Individualisierte Patientenversorgung mit urologischen Implantaten durch biofilmabweisende Oberflächenkonzepte.

Urological implants in the urinary tract are routinely used to ensure urine flow. However, the morbidities are numerous concerning long-term derivations. Especially with the ureteral stents, failure can have considerable consequences. Since the surfaces of all urological implants are more or less ideal substrates for microorganisms, the formation of bacterial biofilms is a regularly observed and often serious complication, which in many cases forces early implant replacement. The burden on the patient and the health system are enormous. This article provides an overview of the numerous strategies developed or under development to protect against bacterial adhesion. Observations in use show "sometimes good, sometimes bad results" for all strategies, which may be due to the fact that the treated patients have different biological and clinical conditions. The implants are each equipped with defense mechanisms designed for certain "scenarios"; if they are used inadequately in this respect, they cannot optimally fulfill their task. Systematic observations of the "outcomes" and evaluation of the obtained data would be necessary in order to be able to assign an "optimal" effect spectrum to each defense strategy, thus, ultimately prospectively giving patients the most suitable product in advance. Systematic use of the existing implant concepts can avoid a large number of implant-related complications "ad hoc"; further development steps with regard to improved surface modifications can be made more specifically. However, the hope of a "super strategy" is likely to remain unfulfilled because bacteria as "opponents" have already proved billions of years of survival.

In Vitro Effects of a Novel Coating Agent on Bacterial Biofilm Development on Ureteral Stents.

OBJECTIVES: Ureteral stenting is a widely used method for noninvasive urinary drainage in ureteral obstruction. However, biofilm development due to transient bacteriuria can cause severe complications such as incrustation with subsequent obstruction as well as recurrent urinary tract infection. Apart from local ailment such as dysuria, this increases both stent replacement frequency and incidence of complications. In this work, we investigated in vitro the bacterial adhesion to a surface-attached and cross-linked poly(N,N-dimethylacrylamide) (PDMAA) hydrogel network, which is known for its nonfouling and protein-repellent characteristics. MATERIALS AND METHODS: To mimic the conditions encountered in vivo, PDMAA-coated and uncoated cyclic olefin polymer (COP) slides as well as polyurethane (PU)-coated glass slides were incubated in sterile human urine for 48 hours. Colonization was then simulated by adding known uropathogens, cultivated from clinical urine samples (such as Escherichia coli). After further incubation for 24 and 48 hours, slides were washed, and the remaining adherent bacteria were solubilized by ultrasound. CFUs were counted after plating and incubation for 48 hours of the resulting solution. RESULTS: PDMAA reduced adherent E. coli about fivefold on coated PU glass slides as well as in PDMAA-coated COP slides. With adherent Enterococcus faecalis and Klebsiella pneumoniae there was a tendency to decreased biofilm formation, but the difference was not statistically significant. CONCLUSIONS: PDMAA reduces surface adherence of the most common uropathogen significantly. Assessment of clinical relevance and of the effect on further uropathogens needs further experimental and clinical evaluations. German Clinical Trial Register ID: DRKS00013264 (approved WHO primary register).

Pathological changes and bacteriological assessments in the urinary tract of pregnant goats experimentally infected with Brucella melitensis.

BACKGROUND: This study was conducted to investigate the pathological changes and distribution of B. melitensis in the urinary tract of pregnant goats following acute experimental infection. Six Jamnapari crossbred does in their third trimester of pregnancy were randomly assigned into two groups; Group 1 was uninfected control and Group 2 was inoculated conjunctival with 0.1 mL of the inoculums containing 109 cfu/mL of live B. melitensis. All does were sacrificed 30 days post-inoculation before the kidney, ureter, urinary bladder, urethra and vaginal swab were collected for isolation of B. melitensis. The same tissue samples were fixed in 10% neutral buffered formalin for hematoxylin and eosin, and immunoperoxidase staining. RESULTS: None of the goats showed clinical signs or gross lesions. The most consistent histopathology finding was the infiltration of mononuclear cells, chiefly the macrophages with few lymphocytes and occasionally neutrophils in all organs along the urinary tract of the infected goats of Group 2. Other histopathology findings included mild necrosis of the epithelial cells of the renal tubules, congestion and occasional haemorrhages in the various tissues. Kidneys showed the most severe lesions. Immunoperoxidase staining revealed the presence of B. melitensis within the infiltrating macrophages and the epithelium of renal tubules, ureter, urethra and urinary bladder. Most extensive distribution was observed in the urinary bladder. Brucella melitensis was successfully isolated at low concentration (3.4 × 103 cfu/g) in the various organs of the urinary tract and at high concentration (2.4 × 108 cfu/mL) in the vaginal swabs of all infected goats. Although B. melitensis was successfully isolated from the various organs of the urinary tract, it was not isolated from the urine samples that were collected from the urinary bladder at necropsy. CONCLUSION: This study demonstrates the presence of low concentrations of B. melitensis in the organs of urinary tract of pregnant does, resulting in mild histopathology lesions. However, B. melitensis was not isolated from the urine that was collected from the urinary bladder.

A randomized controlled trial comparing antimicrobial (silver sulfadiazine)-coated ureteral stents with non-coated stents.

OBJECTIVE: The aim of this study was to compare the efficacy of antimicrobial [silver sulfadiazine (SSD)]-coated ureteral stents with non-coated stents in the prevention of stent-related bacteriuria. MATERIALS AND METHODS: A randomized controlled trial was conducted between September 2014 and September 2016 after approval from the local ethics committee. Inclusion criteria were adults who underwent unilateral double-J ureteral stent placement after ureteroscopic lithotripsy. All patients underwent placement of the same stent type (Carbothan® with hydrophilic surface) and dimensions (6 F, 26 cm). In the test group, stents were coated with SSD. Patients who used antibiotics during the stenting period or underwent stent removal elsewhere were excluded from the study. Urine and stent cultures were obtained on the day of stent removal. All patients answered the Ureteral Stent Symptom Questionnaire (USSQ). RESULTS: The study included 126 patients. The mean ± SD stent duration was 3.1 ± 1.2 weeks. There were no significant differences between groups in the incidence of bacteriuria and USSQ scores. However, two stents (3.2%) in the SSD group had significant bacterial growth, compared to eight stents (12.5%) in the control group (p = 0.054). The incidence of newly diagnosed bacteriuria was higher in the control group (11%) than the antimicrobial group (6.5%), but the difference was not significant (p = 0.372). CONCLUSIONS: This study could not justify the use of antimicrobial (SSD)-coated stents for short stenting periods. The trend towards decreasing stent colonization in the antimicrobial group was not translated to a significantly lower incidence of stent-related bacteriuria or improvement in patients' quality of life.

Comparision of Ureteral Stent Colonization Between Deceased and Live Donor Renal Transplant Recipients.

BACKGROUND: The use of a ureteral stent can cause a urinary tract infection (UTI), although it reduces urologic complications. UTIs are associated with a higher rate of ureteral stent colonization (USC). The aim of this study was to compare USC in living and deceased donor renal transplant recipients. MATERIAL AND METHODS: We conducted a prospective study of 48 patients who underwent renal transplantation between January and December 2016. The stents were removed aseptically, the inner surface of proximal and distal ends of stents were irrigated with liquid culture medium, and then they were vortexed for bacteriological investigation. Urine cultures were taken at the same time. RESULTS: A total of 45 renal transplantation patients (21 from cadavers, 24 from live donors) were evaluated in the study. The duration time of stent retention in patients with live donors was 25.04 ± 4.55 and in patients with deceased donors was 26.19 ± 4.08 days (P = .376). USC was observed in 12 (57.1%) and 6 (25%) patients while positive urine culture (PUC) was detected in 5 (23.8%) and 2 (8.3%) patients in deceased and live donor transplant recipients, respectively. Although the USC rate was significantly higher in the deceased donor renal transplant group (P = .022), there was no significant different in the rates of PUC (P = .137). Enterecoccus species was the common pathogen isolated from ureteral stent and urine. The micro-organisms isolated from ureteral stent in deceased and live donors, respectively, were distributed as follows: Enterococcus 5/3, Candida 3/1, Escherichia coli 2/1, Klebsiella pneumonia 1/1, and staphylococci in 1/0 patients. All E coli and K pneumoniae are extended spectrum beta-lactamase (ESBL)-positive isolates and resistant to sulfamethoxazole-trimethoprim (SMX/TMP). CONCLUSIONS: We report a high incidence of USC in deceased renal transplants. Enterecoccus instead of E coli is the most common pathogen during the first month after transplantation. Transplantation centers should be aware that deceased donor renal transplant recipients are more prone to stent-related infection and the antibacterial resistance rapidly increases in uropathogens.

Obstructive uropathy as initial presentation of genitourinary tuberculosis and masquerading as a postsurgical complication.

A 46-year-old woman who had a recent total abdominal hysterectomy presented with a 1 month history of lower abdominal pain, 1 week of nausea and vomiting as well as decreased urinary output preceded by a year of significant unintentional weight loss. On renal imaging, she was found to have bilateral hydronephrosis and hydroureters in the setting of bilateral distal ureteric obstruction complicated with acute kidney injury and severe hyperkalaemia requiring haemodialysis. The initial concern was for ureteric injury, a known complication of abdominal hysterectomy procedures, however, a urological intervention, performed 9 months later to relieve the ureteric obstruction, revealed purulent material within the left ureter that was smear positive for acid fast bacilli. A GeneXpert test was positive for Mycobacterium tuberculosis She was diagnosed with genitourinary tuberculosis and responded well to antitubercular treatment and haemodialysis was discontinued after the surgery relieved her ureteric obstruction.

Evaluation of Ureteral Stent Colonization in Live-Donor Renal Transplant Recipients.

BACKGROUND: Ureteral stent insertion during kidney transplantation is a matter of debate. Stenting has been proven to reduce the risk of surgical complications. In addition, it has been reported to increase risks such as urinary tract infections especially after operation. Ureteral stent colonization (USC) is known to play a role in the pathogenesis of stent related-infections. The aim of this study was (1) to assess the frequency of USC and values of urine cultures in identifying colonizing bacteria; (2) to assess the importance of indwelling time for USC in live-donor renal transplant recipients; and (3) to evaluate the biomarker role of neutrophil-to-lymphocyte ratio (NLR) on USC. METHODS: A total of 107 live-donor kidney transplant patients were included in the study (76 men and 31 women). The mean age was 43.7 years, and average indwelling time of the ureteral stent was 24.7 days. Patients were divided into three groups according to indwelling stent time as group 1: 15 to 21 days (3rd week), group 2: 22 to 28 days (4th week), and group 3: 29 to 35 days (5th week). The decision to remove the stent was primarily based on clinical judgment. Ureteral stents were removed with the use of flexible cystoscopy. Midstream urine for urine culture and blood samples for NLR were taken prior to stent removal. The removed stents were divided into three parts and taken for bacteriological investigation. RESULTS: Of 107 patients, USC was detected in 24 (22.4%) patients, whereas urinary proliferation was observed in 8 (7.4%) patients. The most common microorganisms found in USC was the Enterecoccus species. The most common microorganisms in urinary culture were Enterecoccus spp. and Klebsiella pnemoniae. All patients with isolated microorganisms in the urine had USC (P < .001). On the other hand, proliferation in urinary culture was observed only in 30% of patients. Urine culture was not significant in identification of USC (P = .063). The three patient groups that were determined according to indwelling stent time were compared in terms of USC, proliferation in urine culture, and NLR. The highest incidence of USC was found in group 3 (44%) and the least in group 2 (11%) (P < .05). No significant difference was found between the groups in terms of urine culture (P = .546). Although no significant difference was found between groups 1 and 2 in NLR values (P = .755), NLR was significantly higher in group 3 (P = .026). CONCLUSIONS: Colonization is common in ureteral stents inserted in live-donor kidney transplant patients, although routine urine culture is insufficient in identfying this colonization. The most common microorganism detected in ureteral stent colonization was Enterecoccus spp. The 4th week was the most convenient time for stent removal time in terms of USC among the 3rd, 4th, and 5th weeks. In addition, increased NLR might have value as a biomarker for USC.

Biofilm formation on ureteral stents - Incidence, clinical impact, and prevention.

Ureteral stents are a simple, minimally invasive method of maintaining ureteral drainage to assure renal function, treat pain caused by ureteral obstruction and avoid external or visible devices. Ureteral stenting is, however, associated with a clear side-effect profile, including irritation on voiding, pain and haematuria. Complications such as stent dysfunction and clinically significant urinary tract infections are also regularly observed. Although this has not yet been thoroughly researched, it appears that biofilm formation on ureteral stents plays a key role in the associated morbidity. In this review, we summarise the current evidence and identify areas that should be further studied to reduce the morbidity associated with ureteral stenting.