High seroprevalence of feline morbilliviruses in free-roaming domestic cats in Chile.

Feline morbillivirus infections have gained increased attention due to repeated reports of their association with urinary tract disease in cats. In the present study, 112 serum samples from free-roaming domestic cats in Chile were tested for antibodies against feline morbillivirus genotypes 1 and 2 (FeMV-1 and FeMV-2) using an indirect immunofluorescence assay. In total, 63% of the animals showed antibodies against one or both FeMV genotypes. Antibodies directed exclusively against FeMV-2 were significantly more prevalent in male cats. The correlation of sex and FeMV-2 infection might give insight into potential routes of transmission. We provide, for the first time, serological data on FeMV in Chile.

Frequency of serious bacterial infections in young infants with and without viral respiratory infections.

BACKGROUND: The goal of our investigation was to describe the incidence of serious bacterial infection (SBI, defined as bacteremia, urinary tract infection (UTI), or meningitis) in young infants with and without documented viral pathogens. METHODS: This was a retrospective cross-sectional study (1/2016-12/2017) in 3 emergency departments (EDs). Previously healthy 0-60-day-old infants were included if at least respiratory viral testing and a blood culture was obtained. The frequency of SBI, the primary outcome, was compared among infants with/without respiratory viral infections using the Pearson Chi-square test (or Fisher's Exact Test) and unadjusted odds ratios (OR). RESULTS: The median age of the 597-infant cohort was 32 days (interquartile range: 20-45 days); 42% were female. Eighty-three percent were well appearing in the ED and 72% were admitted. ED triage vitals commonly revealed tachypnea (68%), pyrexia (45%), and tachycardia (28%); hypoxemia (5%) was uncommon. Twenty-eight percent had positive viral testing, most commonly RSV (93/169, 55%), parainfluenza (29, 17%), and influenza A (23, 14%). Eighty-three infants (13.9%) had SBI: 8.4% (n = 50) had UTI alone, 2.8% (n = 17) had bacteremia alone, 1.2% (n = 7) had bacteremia + UTI, 1.0% (n = 6) had bacteremia + meningitis, and 0.5% (n = 3) had meningitis alone. Infants with documented respiratory viral pathogens were less likely to have any SBI (OR: 0.23; 95% CI: 0.11-0.50), UTI (OR 0.22, 95% CI: 0.09-0.56), or bacteremia (OR 0.27, 95% CI: 0.08-0.9) than infants with negative viral testing. There was no difference in meningitis frequency based on viral status (OR: 0.13, 95% CI: 0.008-2.25). CONCLUSIONS: The frequency of bacteremia and UTI was lower in young infants with respiratory viral infections compared to infants with negative respiratory viral testing.

Fecal occult blood and urinary cytology tests for rapid screening of inflammatory infection in the gastrointestinal and urological systems in patients with Coronavirus disease 2019.

BACKGROUND: Gastrointestinal infections (GI) and urological infections (UI) have not been fully addressed in COVID-19 patients. We aimed to evaluate the values of routine fecal occult blood (FOB) test and urinary cytology test (UCT) for screening of GI and UI in COVID-19 patients. METHODS: In this retrospective study, COVID-19 patients without associated comorbidities were divided into FOB- or UCT-positive or FOB- or UCT-negative groups. Their clinical characteristics and laboratory findings were then compared. RESULTS: A total of 13.6% of patients (47 of 345) tested positive for FOB, and 57.4% (27 of 47) of these patients lacked gastrointestinal symptoms. A total of 30.1% of patients (104 of 345) exhibited gastrointestinal symptoms, and 38.0% (131 of 345) were positive for either FOB or gastrointestinal symptoms. FOB-positive patients possessed significantly higher levels of C-reactive protein and fewer lymphocytes than FOB-negative patients. A total of 36.9% of patients (80 of 217) exhibited positive UCT, and 97.5% (78 of 80) of these patients possessed normal levels of serum markers for renal injuries. Significant differences in age and sex ratios were observed between the UCT-positive and UCT-negative groups, and 72.4% (42 of 58) of female patients over 60 years old were UCT-positive. CONCLUSIONS: Fecal occult blood test in combination with gastrointestinal symptoms could serve as a simple and useful screening approach for GI diagnoses for COVID-19. Age and sex are risk factors for UI in COVID-19 patients. UCT could be a sensitive tool for assessing early UI at a stage in which serum markers for renal injuries appear normal.

Oral Fosfomycin Efficacy with Variable Urinary Exposures following Single and Multiple Doses against Enterobacterales: the Importance of Heteroresistance for Growth Outcome.

Oral fosfomycin trometamol is licensed as a single oral dose for the treatment of uncomplicated urinary tract infections, with activity against multidrug-resistant uropathogens. The impact of interindividual variability in urinary concentrations on antimicrobial efficacy, and any benefit of giving multiple doses, is uncertain. We therefore performed pharmacodynamic profiling of oral fosfomycin, using a dynamic bladder infection in vitro model, to assess high and low urinary exposures following a single oral dose and three repeat doses given every 72 h, 48 h, and 24 h against 16 clinical isolates with various MICs of fosfomycin (8 Escherichia coli, 4 Enterobacter cloacae, and 4 Klebsiella pneumoniae isolates). Baseline fosfomycin high-level-resistant (HLR) subpopulations were detected prior to drug exposure in half of the isolates (2 E. coli, 2 E. cloacae, and 4 K. pneumoniae isolates; proportion, 1 × 10-5 to 5 × 10-4% of the total population). Fosfomycin exposures were accurately reproduced compared to mathematical modeling (linear regression slope, 1.1; R2, 0.99), with a bias of 3.8% ± 5.7%. All 5/5 isolates with MICs of ≤1 µg/ml had no HLR and were killed, whereas 8/11 isolates with higher MICs regrew regardless of exposure to high or low urinary concentrations. A disk diffusion zone of <24 mm was a better predictor for baseline HLR and regrowth. Administering 3 doses with average exposures provided very limited additional kill. These results suggest that baseline heteroresistance is important for treatment response, while increased drug exposure and administering multiple doses may not be better than standard single-dose fosfomycin therapy.

Characterization and spontaneous induction of urinary tract Streptococcus anginosus prophages.

Streptococcus anginosus is an often overlooked and understudied emerging pathogen inhabiting many areas of the human body. Through our sequencing of S. anginosus strains isolated from the female bladder microbiota, we detected numerous prophage sequences. Bioinformatic analysis of these sequences identified 17 distinct groups of S. anginosus prophages. The majority of these phages exhibit no sequence homology to previously characterized temperate or virulent phage sequences, indicating an unexplored diversity of Streptococcus phages. By culturing these bacterial isolates, we confirmed that the prophages of five of these groups are capable of induction. One of these putative phages was imaged, the first such evidence of an S. anginosus virus-like particle; it exhibits morphological characteristics of siphoviruses.

Prevalence of respiratory viruses and antiviral MxA responses in children with febrile urinary tract infection.

Blood myxovirus resistance protein A (MxA) has broad antiviral activity, and it is a potential biomarker for symptomatic virus infections. Limited data is available of MxA in coinciding viral and bacterial infections. We investigated blood MxA levels in children hospitalized with a febrile urinary tract infection (UTI) with or without simultaneous respiratory virus infection. We conducted a prospective observational study of 43 children hospitalized with febrile UTI. Nasopharyngeal swab samples were collected at admission and tested for 16 respiratory viruses by nucleic acid detection methods. Respiratory symptoms were recorded, and blood MxA levels were determined. The median age of study children was 4 months (interquartile range, 2-14 months). A respiratory virus was detected in 17 (40%) children with febrile UTI. Of the virus-positive children with febrile UTI, 7 (41%) had simultaneous respiratory symptoms. Blood MxA levels were higher in virus-positive children with respiratory symptoms (median, 778 [interquartile range, 535-2538] µg/L) compared to either virus-negative (155 [94-301] µg/L, P < 0.001) or virus-positive (171 [112-331] µg/L, P = 0.006) children without respiratory symptoms at presentation with febrile UTI. MxA differentiated virus-positive children with respiratory symptoms from virus-negative without symptoms by an area under the receiver operating characteristic curve of 0.96. Respiratory viruses were frequently detected in children with febrile UTI. In UTI with simultaneous respiratory symptoms, host antiviral immune response was demonstrated by elevated blood MxA protein levels. MxA protein could be a robust biomarker of symptomatic viral infection in children with febrile UTI.

Identification of Enterococcus faecalis in a patient with urinary-tract infection based on metagenomic next-generation sequencing: a case report.

BACKGROUND: Urinary tract infection (UTI) caused by various pathogenic microorganisms is ubiquitous in the parts of the urinary system such as kidney, ureter, bladder, and urethra. Currently, clinical detection of UTI is mainly focused on urine culture; however, the diagnostic value of urine culture remains limited due to the time-consuming procedure and low detection rate, especially in patients who have used antibiotics. Generally, treatment for UTI relies on empirical medication rather than pathogen diagnosis, which leads to the inappropriate use of antimicrobial agents and a significant increase in resistant strains. Comparatively, metagenomic next-generation sequencing (mNGS) is capable of overcoming the disadvantages of clinical culture, and identifying pathogens for further treatment. CASE PRESENTATION: A 33-year-old male patient was admitted to hospital with a high fever and chills. None of his autoimmune disease or thyroid function related indicators were positive, and he had no risk of endocarditis. His white blood cell count, C-reactive protein, procalcitonin, interleukin 6, and neutrophil proportion were markedly elevated. He was initially diagnosed as having an infection of unknown etiology. Since empirical treatment of Sulperazon and Metronidazole did not relieve his symptoms, both the blood and urine specimens were examined using traditional culture, serological testing, and mNGS assay. Traditional culture and serological testing produced negative results, while the mNGS assay revealed the presence of a potential pathogen, Enterococcus faecalis, in the urine specimen, which was further confirmed by both Sanger sequencing and qPCR analysis. A CT scan of the patient's whole abdomen showed stones in the right kidney. Once targeted antibiotic therapy was administered, the patient recovered quickly. CONCLUSIONS: Our case illustrated that mNGS, as a novel culture-independent approach, demonstrated the capability of rapid, sensitive, and accurate pathogen identification. Furthermore, this technology provides strong support for guiding clinicians to determine appropriate treatment.

Protective association between JC polyoma viruria and kidney disease.

PURPOSE OF REVIEW: The presence of viruses in urine (urine virome) typically reflects infection in the kidneys and urinary tract. The urinary virome is associated with HIV-associated nephropathy and chronic glomerulosclerosis. There are many associations of this microbiome with human diseases that remain to be described. This manuscript reviews emerging data on relationships between kidney disease and urinary tract infection/colonization with JC polyomavirus (JCPyV). RECENT FINDINGS: Approximately 30% of the adult population sheds JCPyV in the urine. Further, urinary tract infection with one polyomavirus strain appears to inhibit secondary infections. The presence of urinary JCPyV and BK polyomavirus (BKPyV) replication were measured with polymerase chain reaction in African Americans to assess relationships with apolipoprotein L1 gene (APOL1)-associated nephropathy. Urinary JCPyV was associated with paradoxically lower rates of nephropathy in those with APOL1 high-risk genotypes. Subsequent studies revealed African Americans with JCPyV viruria had lower rates of nondiabetic nephropathy independent from APOL1. SUMMARY: Urinary tract JCPyV replication is common and associates with lower rates of nephropathy. This relationship is observed in diverse settings. Results support a host immune system that fails to eradicate nonnephropathic viruses and is also less likely to manifest renal parenchymal inflammation resulting in glomerulosclerosis.

BK virus-associated viruria and viremia in a patient with lymphangioleiomyomatosis after lung re-transplantation: A case report and review of the literature on BK virus infection post-lung transplantation.

The BK virus (BKV) is a member of the polyomaviridae family of DNA viruses. BKV reactivates under a highly immunosuppressed state and causes renal dysfunction. In renal transplant patients, BKV infection leads to tubular impairment and loss of transplanted kidney grafts. However, few studies have reported on the relationship between BKV and lung transplantation. Adjustment of the dosage of immunosuppressants is needed in some cases, but the treatment method has not been established. Here, we report a case of BKV-associated viruria and viremia in a patient with lymphangioleiomyomatosis (LAM) after lung re-transplantation. A 44-year-old female refractory LAM patient who had undergone lung re-transplantation 3 months earlier was diagnosed with BKV-associated viruria and viremia. Urine cytology indicated decoy cells and the urine and serum polymerase chain reaction test was positive for BKV. As scheduled after re-transplantation surgery, immunosuppressive drugs were progressively reduced. This patient was considered to have experienced spontaneous BKV-associated viremia and viruria. Review of the literature suggested that 17%-42% of BKV-associated viruria cases have been reported after lung transplantation, but cases of BKV-associated nephropathy are rarely reported. Based on the present case, doctors involved in lung transplantation should monitor patients for BKV infection. Decoy cell monitoring by urine cytology is a useful screening method in the follow-up observation after lung transplantation. Early-stage interventions may prevent BKV-associated nephropathy even in patients who have developed BKV viremia, and sirolimus can be administered to patients with histories of BKV infection if they are carefully monitored.

[The role of viral infection in the development of recurrent lower urinary tract infections].

This review is dedicated to the problems of diagnosing recurrent lower urinary tract infections caused by viruses. The literature search was conducted using the Medline, PubMed, EMBASE, CNKI, and WANG FANG databases. Further study of virobiota and microbiome of urine both in normal and in pathological conditions are warranted.

[Concomitant urogenital infections in men].

The article presents possible combinations of urogenital infections of various etiologies and some pathogenetic, clinical and epidemiological features, and issues of epidemiological surveillance for co-infection. The authors describe in detail combinations with each other and with other diseases of such pathogens as Chlamydia trachomatis, Ureaplasma urealyticum, Mycoplasma spp., Neisseria gonorrhoeae, Trichomonas vaginalis. They also focus on the problem of co-occurrence of human papillomavirus (HPV) with other urogenital pathogens. The article raises the question of the need to introduce new scientific data on the epidemiology of concomitant urogenital infections in men in the practice of diagnosis, treatment, registration, and implementation of preventive and anti-epidemic measures.

Bacteriophages to reduce gut carriage of antibiotic resistant uropathogens with low impact on microbiota composition.

Uropathogenic Escherichia coli (UPEC) is the leading cause of urinary tract infections (UTIs) worldwide, causing over 150 million clinical cases annually. There is currently no specific treatment addressing the asymptomatic carriage in the gut of UPEC before they initiate UTIs. This study investigates the efficacy of virulent bacteriophages to decrease carriage of gut pathogens. Three virulent bacteriophages infecting an antibiotic-resistant UPEC strain were isolated and characterized both in vitro and in vivo. A new experimental murine model of gut carriage of E. coli was elaborated and the impact of virulent bacteriophages on colonization levels and microbiota diversity was assessed. A single dose of a cocktail of the three bacteriophages led to a sharp decrease in E. coli levels throughout the gut. We also observed that microbiota diversity was much less affected by bacteriophages than by antibiotics. Therefore, virulent bacteriophages can efficiently target UPEC strains residing in the gut, with potentially profound public health and economic impacts. These results open a new area with the possibility to manipulate specifically the microbiota using virulent bacteriophages, which could have broad applications in many gut-related disorders/diseases and beyond.

Clinical characteristics and outcomes of adenovirus infection of the urinary tract after renal transplantation.

BACKGROUND: Urinary tract infection caused by human adenovirus (HAdV) after renal transplantation (RT) results in graft loss because of concomitant nephropathy and acute rejection and may result in death because of systemic dissemination. METHODS: We assessed the time period between RT and disease onset, symptoms, treatment details, disease duration, renal graft function, outcomes, and complications. RESULTS: HAdV infection of the urinary tract occurred in 8 of 170 renal transplant recipients. Symptoms were macrohematuria in all 8 patients, dysuria in 7, and fever in 5. The median period from RT to disease onset was 367 (range, 7-1763) days, and the median disease duration was 15 (range, 8-42) days. The mean serum creatinine (sCr) level prior to onset was 1.35 ± 0.48 mg/dL and the mean maximum sCr level during disease was 2.34 ± 1.95 mg/dL. These values were increased by ≥25% in 5 patients. The mean sCr levels when symptoms resolved was 1.54 ± 0.67 mg/dL, and no significant difference was seen before, during, or after disease onset (P = 0.069). Two patients were diagnosed with HAdV viremia and 1 with acute tubulointerstitial nephritis revealed on biopsy. In addition to a reduction in immunosuppressant dosage, 2 patients received gammaglobulins and 5 received ganciclovir. CONCLUSION: Symptoms of all patients were alleviated, although some patients developed nephritis or viremia. Hence, the possibility of exacerbation should always be considered. Adequate follow-up observation should be conducted, and diligent and aggressive therapeutic intervention is required to prevent the condition from worsening.

[Types of infectious complications exciters in recipients of related kidneys].

AIM: To investigate the nature of microflora causing an infectious-inflammatory complications in recipients of related kidney in the early postoperative period and to substantiate the effectiveness of antibiotic prophylaxis and antibiotic therapy depending on pathogen type with the determination of its sensitivity to antimicrobial agents. MATERIAL AND METHODS: The medical records of 255 patients who underwent kidney transplantation from a living related donor from 2007 to 2014 were analyzed. Foci of infection were sanitized preoperatively to prevent infectious complications in post-transplantation period. Immunosuppression induction was achieved using 2-fold administration of Kempas or Simulect. Corticosteroids, ciclosporin, prograf, advagraf, myfortic, neoral, sertican were used for routine immunosuppression. Complications after kidney transplantation were detected in 65 (25.5%) patients including 38 (14.9%) infectious and 27 (10.6%) non-infectious complications. The material for microbiological examination included blood, urine, sputum, wound discharge, bronchial lavage. Extraction and identification of microorganisms were carried out according to conventional techniques as well as using automatic Vitec-2 Compact analizer («BioMeriex¼, France). Sensitivity to antibiotics was determined using Vitek-2 Compact analyzer. The functional aspects of transplanted kidney were studied in 255 patients. Normal and decreased function of kidney was observed in 221 (86.6%) and 30 (11.8%) cases respectively. Transplantant did not function in 4 (1.57%) patients. RESULTS: The probability of infection is highest in the early postoperative period. Risk factors were inadequate and prolonged antibiotic therapy, unrecognized infection postoperatively. The main problem in renal transplant recipients is urinary tract infection (90% of patients).

Asymptomatic hematuria associated with urinary polyomavirus infection in immunocompetent patients.

Unlike the case for immunodeficient patients, little is known about polyomavirus (PV) infection in immunocompetent patients. PV infection in immunocompetent individuals has been reported sporadically, but little is known about asymptomatic hematuria. To determine the clinical significance and prevalence of urinary PV infection in immunocompetent patients, a total of 95 individuals admitted to Seoul St. Mary's hospital were investigated. Sixty-four patients were enrolled for evaluation of asymptomatic hematuria, and 31 healthy individuals served as controls. Clinical screening for PV infection was performed by urine cytology analysis by liquid-based preparation and urine RT-PCR for BK virus (BKV) and JC virus (JCV), respectively. The average age of the patients in the PV(+) - and PV(-) -groups with asymptomatic hematuria were 60 years and 46 years, respectively. Urine cytology analysis revealed decoy cells in 37/64 hematuria patients (38.9%), but not in healthy controls. They were more prevalent in male patients. Eighty-two patients (86.3%) had PV viruria, viz., 54/64 patients in the hematuria group and 28/31 in the control group. Interestingly, 28/31 (90.3%) cases in the healthy control group were positive for PV viruria, which exceeded the number in the hematuria group (84.4%). PV viruria was associated primarily with JCV, rather than BKV. PV viruria, including JCV viruria, correlated with urine decoy cells and increased age. In conclusion, urinary PV infection is common in immunocompetent patients with asymptomatic hematuria and is age-related. These data may provide an insight into the pathogenesis and future treatment of asymptomatic hematuria associated with urinary PV infection in immunocompetent patients.

Renal abnormalities among HIV-infected, antiretroviral naive children, Harare, Zimbabwe: a cross-sectional study.

BACKGROUND: Data on the prevalence of renal and urine abnormalities among HIV-infected children in Sub-Saharan Africa are limited. We set out to determine the prevalence of proteinuria; low estimated glomerular filtration rate (eGFR), urinary tract infection and associated factors among HIV-infected antiretroviral therapy (ART) naive children, aged 2-12 years, attending the paediatric HIV clinic at a tertiary hospital in Harare. METHODS: Consecutive ART naive children attending the clinic between June and October 2009 were recruited. Detailed medical history was obtained and a complete physical examination was performed. Children were screened for urinary tract infection and for significant persistent proteinuria. Serum creatinine was used to estimate GFR using the modified Counahan-Barratt formula. The Student's t-test was used to analyse continuous variables and the chi-square or Fisher's exact test was used to analyse categorical data. Logistic regression was performed to assess the relationship between study factors and urine abnormalities, persistent proteinuria and the eGFR. RESULTS: Two hundred and twenty children were enrolled into the study. The median age was 90 months (Q1=65.5; Q3=116.5). The prevalence of urinary tract infection was 9.5%. Escherichia coli was the predominant organism. There was uniform resistance to cotrimoxazole. Persistent proteinuria (urine protein to creatinine ratio greater than 0.2, a week apart) was found in 5% of the children. Seventy-five children (34.6%) had mild to moderate renal impairment shown by a low eGFR (30 to <90 ml/min/1.73 m2). Persistent proteinuria was more likely to be found in children who were wasted, weight-for-height (WHZ) z-score <-2 (p=0.0005). Children with WHO clinical stage 4 were more likely to have a low eGFR than children with less advanced stages (OR 2.68; CI 1.24-5.80). Urine abnormalities were more likely to be observed in children with WHO clinical stages 3 and 4 (OR 2.20; CI 1.06-4.60). CONCLUSION: There is significant renal impairment among HIV-infected, ART naive children aged 2-12 years attending the outpatient paediatric HIV clinic at Harare Central Hospital. The abnormalities are more likely to occur in children with advanced HIV/AIDS. Screening for renal impairment and urinary tract infections in HIV-infected children before initiation of ART and regularly thereafter would be helpful in their management. KEYWORDS: HIV, renal disease, persistent proteinuria, glomerular filtration rate, urinary tract infection.

Phage therapy of Cronobacter-induced urinary tract infection in mice.

BACKGROUND: Cronobacter spp. is an opportunistic pathogen causing rare but dangerous cases of meningitis, sepsis and urinary tract infection. Phage therapy overcomes antibiotic resistance and represents an alternative approach to standard antimicrobial treatment. There are no published studies on the use of phages against Cronobacter spp. in vivo. The aim of our study was to prove the effects of isolated Cronobacter-specific phages on renal colonization in a model of urinary tract infection in mice. MATERIAL/METHODS: Urinary tract infection was induced by transurethral application of Cronobacter turicensis (1011 CFU/ml). Simultaneously, isolated Cronobacter-specific phages were administered intraperitoneally (1011 PFU/ml). After 24 hours, kidneys and bladder were collected and used for cultivation and analysis of gene expression and oxidative stress markers. RESULTS: Phage therapy reduced the number of Cronobacter colonies in the kidney by 70%. Higher levels of malondialdehyde were reduced by phage therapy without affecting the antioxidant status. The expression of pro-inflammatory cytokines tumor necrosis factor-alpha and monocyte chemoattractant protein-1 increased by the infection and was attenuated by phage therapy. CONCLUSIONS: Phage therapy proved effective in the prevention of ascending renal infection in a murine model of urinary tract infection. Long-term effects and safety of the treatment are currently unknown. Further studies should test phage therapy in other Cronobacter infection models.

Novel 3D organotypic urothelial cell culture model for identification of new therapeutic approaches in urological infections.

PURPOSE: 3D organotypic cell cultures offer the possibility to study cell growth in a more in vivo like situation. To our knowledge no 3D culture of primary urothelial cells has been established yet. BK Polyomavirus (BKPyV), replicating in urothelial cells, may cause haemorrhagic cystitis in immunocompromised patients. PRIMARY ENDPOINTS OF THIS STUDY: Establishment of a 3D organotypic cell culture of primary urothelial cells and fibroblasts; use of this model as infection model for archetype BKPyV; description of first parts of viral life cycle with identification of therapeutic targets. METHODS: This is an experimental study. Primary urothelial cells were purchased from CellnTec, Bern, Switzerland; fibroblasts were isolated from the ureter of patients with no urothelial malignancy in their medical history. As main methods we used quantitative real-time PCR and immunohistochemistry. Outcomes were analysed using SPSS 23.0. RESULTS: We were able to develop a 3D organotypic culture for primary urothelium. An infection with archetype BKPyV was established in this model with virus replication rates up to 6.41 × 108 copies/ml on day 9 following Infection. Interestingly, proliferation rate of the urothelial cells is significantly (p = 0.049 at day 6 following infection) elevated while cells are losing differentiation under infection. Phosphorylated STAT3 is also significantly elevated (p < 0.0001) during infection. CONCLUSIONS: The established of urothelial 3D cultures is a new method to study several urothelial diseases. The archetype BKPyV infection model is novel and the first method to study archetype viral life cycle. The STAT3 pathway might be an interesting target for the development of a causal therapy.

Urine Donor-Derived Cell-Free DNA Helps Discriminate BK Polyomavirus-Associated Nephropathy in Kidney Transplant Recipients With BK Polyomavirus Infection.

Background: Studies have shown that plasma donor-derived cell-free DNA (dd-cfDNA) can predict renal allograft antibody-mediated rejection. This study was performed to evaluate the value of urine dd-cfDNA concentration and dd-cfDNA fraction (%) for discriminating BK polyomavirus-associated nephropathy (BKPyVAN) in kidney transplant recipients with urinary BK polyomavirus (BKPyV) infection. Methods: In this retrospective single-center observational study, we enrolled kidney transplant recipients who were diagnosed with urine BKPyV infection between August 2018 and May 2019 at the First Affiliated Hospital of Sun Yat-sen University. Urine dd-cfDNA was measured by using a novel target region capture sequencing methodology. The pathological diagnosis of BKPyVAN was confirmed by anti-SV40-T immunohistochemical staining and classified using the American Society for Transplantation schema. Receiver operating characteristic curve analysis was used to investigate the relations of urine dd-cfDNA and dd-cfDNA% to intrarenal allograft BKPyV infection states. Results: In total, 93 patients were enrolled, including 40 cases of proven BKPyVAN, seven cases of probable BKPyVAN, 23 cases of possible BKPyVAN, and 23 cases of resolving BKPyVAN. Urine dd-cfDNA level in proven BKPyVAN (22.09 ± 21.27 ng/ml) was comparable to that in probable BKPyVAN (15.64 ± 6.73 ng/ml, P = 0.434) but was significantly higher than that in possible BKPyVAN (5.60 ± 3.53 ng/ml) and resolving BKPyVAN (5.30 ± 3.34 ng/ml) (both Ps < 0.05). Urine dd-cfDNA% of proven BKPyVAN (0.71 ± 0.21) was lower than that of probable BKPyVAN (0.91 ± 0.04, P < 0.001), but was significantly higher than that of possible BKPyVAN (0.56 ± 0.30) and resolving BKPyVAN (0.46 ± 0.28) (both Ps < 0.05). For distinguishing biopsy-proven BKPyVAN from biopsy-excluded BKPyVAN, the discrimination capacity of urine dd-cfDNA (AUC: 0.842, 95% CI: 0.735, 0.918) was superior to that of plasma BKPyV DNA load (AUC: 0.660, 95% CI: 0.537, 0.769) with 0.181 (95% CI: 0.043, 0.319) difference between areas under ROC curves (P = 0.010). Conclusion: The elevated urine dd-cfDNA level may help discriminate BKPyVAN in kidney transplant recipients with BKPyV viruria.