Urosepsis--from the view of the urologist

Urinary Tract Infection Predictors in Patients Undergoing Retrograde IntraRenal Surgery for Renal Stones: Does the Instrument Make the Difference?

Background: Retrograde intrarenal surgery (RIRS) using flexible ureterorenoscopes is a cornerstone approach for renal stone removal, yet it carries a significant risk of postoperative urinary tract infection (UTI). With the emergence of single-use ureterorenoscopes, there is growing interest in their potential to mitigate this risk. This study aimed to compare the postoperative infection rates between single-use and multi-use ureterorenoscopes in RIRS procedures and to identify predictors of postoperative UTI. Methods: Data were collected from 112 consecutive patients who underwent RIRS for renal stones between March 2022 and September 2023. Peri-operative variables including age, gender, body mass index (BMI), stone size, stone location, type of ureterorenoscope, Hounsfield Units (HU), pre-operative hydronephrosis, laboratory analysis, and operative time were evaluated. Univariate and multivariate logistic regression analyses were performed to assess the predictors of postoperative UTI. Results: Of the cohort, 77 surgeries (68.7%) utilized multi-use ureterorenoscopes, while 35 (31.3%) utilized single-use devices. Stone diameter, number of stones, type of ureterorenoscope, and operative time were significant predictors of postoperative UTI in the univariate analysis. Multivariable logistic regression showed that operative time (OR, 1.3; 95% CI, 0.55-0.99; p = 0.03) and type of ureterorenoscope (multi-use vs. single-use) (OR, 1.14; 95% CI, 1.08-1.2; p < 0.001) were independent predictors of postoperative UTI. Conclusions: In conclusion, this study highlights that multi-use ureterorenoscopes and prolonged operative time are associated with an increased risk of postoperative UTI in RIRS procedures. Careful pre-operative evaluation and meticulous patient selection are essential to minimize the occurrence of postoperative UTIs and optimize patient outcomes in RIRS for renal stones.

The association between renal pelvis urine density and the risk of severe infectious complications in patient with symptom-free hydronephrosis after shock wave lithotripsy: a multi-center prospective study

Finding reliable and easy-to-obtain predictors of severe infectious complications after shock wave lithotripsy (SWL) is a major clinical need, particular in symptom-free hydronephrosis. Therefore, we aim to prospectively investigate the predictive value of Hounsfield units (HU) in renal pelvis urine for the risk of severe infectious complications in patients with ureteral stones and symptom-free hydronephrosis after SWL. This multi-center prospective study was conducted from June 2020 to December 2023. The HU of renal pelvis urine was measured by non-enhanced computed tomography. The severe infectious complications included systemic inflammatory response syndrome, sepsis, and septic shock. Binary logistic regression models assessed the odds ratios (ORs) and 95% confidence intervals (CIs). Finally, 1,436 patients with ureteral stones were enrolled in this study. 8.9% (128/1,436) of patients experienced severe infectious complications after SWL treatment. After adjusting confounding variables, compared with the patients in the lowest renal pelvis urine density quartile, the OR (95% CI) for the highest quartile was 32.36 (13.32, 78.60). There was a positive linear association between the HU value of renal pelvis urine and the risk of severe infectious complications after SWL (P for trend < 0.001). Furthermore, this association was also observed stratified by age, gender, BMI, stone size, stone location and hydronephrosis grade (all P for interaction > 0.05). Additionally, the nonlinear association employed by restricted cubic splines is not statistically significant (nonlinear P = 0.256). The AUROC and 95%CI of renal pelvis urine density were 0.895 (0.862 to 0.927, P value < 0.001). The cut-off value was 12.0 HU with 78.59% sensitivity and 85.94% specificity. This multi-center prospective study demonstrated a positive linear association between HU in renal pelvis urine and the risk of severe infectious complications in patients with ureteral stones and symptom-free hydronephrosis after SWL, regardless of age, gender, BMI, stone size, stone location, and hydronephrosis grade. These findings might be helpful in the SWL treatment decision-making process.

Four-year variation in pathogen distribution and antimicrobial susceptibility of urosepsis: a single-center retrospective analysis

Background

Urosepsis is a common disease in urology, which is characterized by high treatment costs and high mortality. In the treatment of sepsis, anti-infection therapy is the most important means. However, the effect of empirical anti-infection therapy is often not ideal. Therefore, it is necessary to continuously monitor the prevalence of bacterial isolates in the blood culture of patients with urinary sepsis and their sensitivity to antibacterial drugs. This is of great significance to improve the efficacy of empirical antibiotic therapy for urosepsis.

Objective

To elucidate the landscape of prevailing bacterial profiles and their antimicrobial susceptibilities in urosepsis cases, and to furnish robust clinical evidence to underpin the timely initiation of empirical antibiotic treatment.

Methods

Collect the basic information and blood culture results of patients with urosepsis hospitalized from 2017 to 2020. Retrospective analysis of bacterial species and antimicrobial susceptibility in urosepsis and changes over 4 years.

Results

Gram-negative bacteria (178 isolates, 75.11%) constituted the main pathogens causing urosepsis, followed by Gram-positive bacteria (46 isolates, 19.41%) and fungus (13 isolates, 5.48%). The sensitivity of ertapenem, meropenem, amikacin, and imipenem to Gram-negative bacteria all exceeded 85%. The sensitivity rates of levofloxacin, gentamicin, and ciprofloxacin are decreasing every year (p < 0.05). Tigecycline, vancomycin, and linezolid exhibited excellent sensitivity against Gram-positive bacteria. Among fungi, fluconazole demonstrated universal sensitivity, while itraconazole-resistant isolates have been found, and amphotericin B is still effective.

Conclusion

Analysis of blood culture results of patients more accurately reflected the etiology of urosepsis, mainly Escherichia coli, Enterococcus, and Klebsiella pneumoniae. If there are no definitive blood culture results, empiric treatment of urosepsis should not include fluoroquinolone antibiotics. Cefepime, cefoxitin, and ceftazidime are the most sensitive antibiotics to Gram-negative bacteria besides carbapenem antibiotics. In addition, the current situation regarding extended-spectrum β-lactamase-producing bacteria and carbapenem-resistant Enterobacteriaceae bacteria resistance is extremely concerning with limited therapeutic options available. Strengthening antibiotic management practices and exploring novel antibacterial agents can help mitigate this issue.

Recanalize ureteral stents with focused ultrasound

BACKGROUND

Maintaining ureteral patency is imperative to preventing renal injury and systemic infection. Ureteral stents are small conduits connecting the kidney and the bladder. They have been widely used to treat ureteral obstructions and ureteral leaks. The most problematic and frequent stent-associated complication is stent encrustation. This occurs when mineral crystals (e.g. calcium, oxalate, phosphorus, struvite) are deposited onto the surface and internal lumen of the stent. Encrustation can lead to the obstruction of a stent and increases risk of systemic infection. As a result, ureteral stents need to be replaced typically every 2-3 months.

PURPOSE

In this study, we present a non-invasive, high-intensity focused ultrasound (HIFU)-based technique to recanalize obstructed stents. By taking advantage of the mechanical force produced by a HIFU beam, including acoustic radiation force, acoustic streaming, and cavitation, HIFU can break up encrustations, clearing the stent of obstruction.

METHODS

The ureteral stents for this study were obtained from patients undergoing ureteral stent removal. Under the guidance of ultrasound imaging, the encrustation in the stents were located, and then targeted by HIFU at frequencies of 0.25 and 1 MHz. The duty cycle of HIFU was 10%, and the HIFU burst repetition rate was 1 Hz, while the HIFU amplitude was varied to find the threshold pressure that would displace encrustations. The treatment duration was limited at 2 min (or 120 shots from HIFU). The treatments were carried out in two different orientations (parallel and perpendicular) of the ureteral stent with respect to the HIFU beam. For each setting, five treatments were conducted for a maximum duration of 2 min. During the entire treatment, an ultrasound imaging system was used to monitor the movement of encrustations inside the stent. The peak negative HIFU pressures needed to move the encrustations inside the stent was recorded for quantitative analysis.

RESULTS

Our results demonstrated that at both 0.25 and 1 MHz ultrasound frequencies, obstructed stents could be recanalized. At 0.25 MHz, the needed average peak negative pressure was 0.52 MPa in parallel orientation and 0.42 MPa in perpendicular orientation. At 1 MHz, the needed average peak negative pressure was 1.10 MPa in parallel orientation and 1.15 MPa in perpendicular orientation CONCLUSIONS: This first in-vitro study has demonstrated the feasibility of non-invasive HIFU to recanalize ureteral stents. This technology has a potential to reduce the need for ureteral stent exchange.

Emergency decompression for patients with ureteral stones and SIRS: a prospective randomized clinical study

OBJECTIVE

Patients with ureteral calculi and systemic inflammatory response syndrome (SIRS) often require emergency drainage, and percutaneous nephrostomy (PCN) and retrograde ureteral stent insertion (RUSI) are the most commonly used methods. Our study aimed to identify the best choice (PCN or RUSI) for these patients and to examine the risk factors for progression to urosepsis after decompression.

METHODS

A prospective, randomized clinical study was performed at our hospital from March 2017 to March 2022. Patients with ureteral stones and SIRS were enrolled and randomized to the PCN or RUSI group. Demographic information, clinical features and examination results were collected.

RESULTS

Patients (n = 150) with ureteral stones and SIRS were enrolled into our study, with 78 (52%) patients in the PCN group and 72 (48%) patients in the RUSI group. Demographic information was not significantly different between the groups. The final treatment of calculi was significantly different between the two groups (p < .001). After emergency decompression, urosepsis developed in 28 patients. Patients with urosepsis had a higher procalcitonin (p = .012) and blood culture positivity rate (p < .001) and more pyogenic fluids during primary drainage (p < .001) than patients without urosepsis.

CONCLUSION

PCN and RUSI were effective methods of emergency decompression in patients with ureteral stone and SIRS. Patients with pyonephrosis and a higher PCT should be carefully treated to prevent the progression to urosepsis after decompression.Key messageIn this study, we evaluate the best choice (PCN or RUSI) for patients who have ureteral stones and SIRS and to examine the risk factors for progression to urosepsis after decompression. This study found that PCN and RUSI were effective methods of emergency decompression. Pyonephrosis and higher PCT were risk factors for patients to develop to urosepsis after decompression.

A novel model of urosepsis in rats developed by injection of Escherichia coli into the renal pelvis

Despite extensive research, urosepsis remains a life-threatening, high-mortality disease. Currently, animal models of urosepsis widely accepted by investigators are very scarce. This study aimed to establish a standardized and reproducible model of urosepsis in rats. Forty adult Wistar rats were randomly divided into four groups according to the concentration of injected E. coli suspensions: Sham, Sep 3×, Sep 6×, and Sep 12×. Because the ureter is so thin and fragile, no conventional needle can be inserted into the ureter, which is probably why rats are rarely used to develop models of urosepsis. To solve this problem, the left ureter was ligated in the first procedure. After 24 hours, the left ureter above the ligation was significantly dilated, then saline or different concentrations of E. coli at 3 ml/kg were injected into the left renal pelvis using a 30G needle. The left ureter was subsequently ligated again at a distance of 1 cm from the renal hilum to maintain high pressure in the renal pelvis. Following injection of E. coli or saline for 24 h, three rats from each group were sacrificed and their organs (lung, liver, and right kidney) were collected. In contrast, the remaining seven rats continued to be observed for survival. At 10 days after E. coli injection, rats in the sep12× group had a higher mortality rate (100%) compared to the sep3× group (28.6%) or the sep6× group (71.4%). The significant changes in peripheral blood WBC count, serum IL-6 and TNF-α levels were also in the sep12× group. In addition, rats in the sepsis group showed multi-organ dysfunction, including damage to the lungs, liver, and kidneys. The establishment of a standardized rat model of urosepsis may be of great value for studying the pathophysiological of urosepsis.

Community-onset urosepsis: incidence and risk factors for 30-day mortality - a retrospective cohort study

BACKGROUND

Urosepsis is a life-threatening condition that needs to be addressed without delay. Two critical issues in its management are: (1) Appropriate empirical antibiotic therapy, considering the patients general condition, comorbidity, and the pathogen expected; and (2) Timing of imaging to identify obstruction requiring decompression.

OBJECTIVES

To identify risk factors associated with 30-day mortality in patients with urosepsis.

METHODS

From a cohort of 1,605 community-onset bloodstream infections (CO-BSI), 282 patients with urosepsis were identified in a Swedish county 2019-2020. Risk factors for mortality with crude and adjusted odds ratios were analysed using logistic regression.

RESULTS

Urosepsis was found in 18% (n = 282) of all CO-BSIs. The 30-day all-cause mortality was 14% (n = 38). After multivariable analysis, radiologically detected urinary tract disorder was the predominant risk factor for mortality (OR = 4.63, 95% CI = 1.47-14.56), followed by microbiologically inappropriate empirical antibiotic therapy (OR = 4.19, 95% CI = 1.41-12.48). Time to radiological diagnosis and decompression of obstruction for source control were also important prognostic factors for survival. Interestingly, 15% of blood cultures showed gram-positive species associated with a high 30-day mortality rate of 33%.

CONCLUSION

The 30-day all-cause mortality from urosepsis was 14%. The two main risk factors for mortality were hydronephrosis caused by obstructive stone in the ureter and inappropriate empirical antibiotic therapy. Therefore, early detection of any urinary tract disorder by imaging followed by source control as required, and antibiotic coverage of both gram-negative pathogens and gram-positive species such as E. faecalis to optimise management, is likely to improve survival in patients with urosepsis.

High attenuation value in non-contrast computer tomography can predict pyonephrosis in patients with upper urinary tract stones

To evaluate whether the higher attenuation value [Hounsfield unit (HU)] in non-contrast CT can predict pyonephrosis in patients with upper urinary tract stones (UTS). Between October 2019 and October 2021, patients with hydronephrosis or pyonephrosis secondary to upper UTS were retrospectively searched in our study. All patients with UTS were treated with percutaneous nephrostomy, percutaneous nephrolithotomy, retrograde ureteral stent or transurethral ureteroscope lithotripsy. We excluded patients treated with extracorporeal shock-wave lithotripsy. Patients whose CT was not performed in our hospital or treated in another hospital were also excluded. Clinical data regarding basic information, clinical feature, Calculi-related indicators, HU values of the renal pelvis, the thick wall of the renal pelvis on CT were collected. Univariate and multivariate logistic analyses were performed. Receiver operative characteristic curves were drawn to predict pyonephrosis. A total of 240 patients with UTS were retrospected in this research, 191 patients had hydronephrosis (Group 1), and 49 patients had hydronephrosis with pyonephrosis (Group 2). The HU value of the renal collecting system in Group 2 (mean, 15.46; range, +1/+30) was significantly higher than that in Group 1 (mean, 5.5; 5 range -6/+24) (P = .02); the receiver operative characteristic curve analysis revealed that the best cut-off value of 9.5 could predict the presence of pyonephrosis, with 71.4% sensitivity and 70.2% specificity (area under the curve = 0.613; 95% CI: 0.514-0.713). In this study, we found the HU attenuation value of the renal collecting system can be used to distinguish pyonephrosis from hydronephrosis in patients with UTS.

Planned percutaneous nephrolithotomy in patients who initially presented with urosepsis: Analysis of outcomes and complications

Objective

To compare the outcomes and complications of planned percutaneous nephrolithotomy (PCNL) in patients with a prior urosepsis episode to those without.

Patients and Methods

We recorded patients who presented initially with obstructive urosepsis, as identified by systemic inflammatory response syndrome and obstructing kidney stones. We compared the surgical outcomes and complications among those patients who had planned PCNL after control of prior urosepsis with urgent decompression and antibiotics (Group A) to a group who presented for PCNL with no previous history of a septic presentations (Group B). A 1:1 matched-pair analysis was performed using four parameters (age, gender, body mass index, and American Society of Anesthesiologists classification) to eliminate potential allocation bias. Primary outcomes included were stone-free rate (SFR) and complication rate. Secondary outcomes included were operative time, estimated blood loss, and duration of postoperative hospital stay.

Results

A total of 80 patients underwent PCNL (48 male and 32 females) divided equally between both treatment groups, with a mean (interquartile range) age of 47 (19–75) years. There were no differences in demographic data or stone characteristics between both groups. Both groups had comparable SFRs (92.5% vs 97.5%, P = 0.212) and mean operative time (77 vs 74 min, P = 0.728) (Table 2). Patients in Group A had a significantly higher overall complications rate (35% vs 10%, P = 0.03) . There were no postoperative mortalities and the mean length of hospital stay was significantly longer in Group A patients compared to group B (4.2 vs 1.5 days, P = 0.042).

Conclusions

: Planned PCNL after decompression for urolithiasis-related sepsis has comparable operative time and SFR but higher complication rates and longer postoperative hospital stay. This is critical in counselling patients prior to definitive treatment of kidney stones after urgent decompression for urosepsis and for adequate preoperative planning and preparation.

Abbreviations: ASA: American Society of Anesthesiologists; BMI: body mass index; ICU: intensive care unit; IQR: interquartile range; KUB: plain abdominal radiograph of the kidneys, ureters and bladder; PCN: percutaneous nephrostomy; PCNL: percutaneous nephrolithotomy; SFR: stone-free rate; URS; ureteroscopy; US: ultrasonography

Monoprophylaxis With Cephalosporins for Transrectal Prostate Biopsy After the Fluoroquinolone-Era: A Multi-Institutional Comparison of Severe Infectious Complications

Background

To compare severe infectious complication rates after transrectal prostate biopsies between cephalosporins and fluoroquinolones for antibiotic monoprophylaxis.

Material and Methods

In the multi-institutional cohort, between November 2014 and July 2020 patients received either cefotaxime (single dose intravenously), cefpodoxime (multiple doses orally) or fluoroquinolones (multiple-doses orally or single dose intravenously) for transrectal prostate biopsy prophylaxis. Data were prospectively acquired and retrospectively analyzed. Severe infectious complications were evaluated within 30 days after biopsy. Logistic regression models predicted biopsy-related infectious complications according to antibiotic prophylaxis, application type and patient- and procedure-related risk factors.

Results

Of 793 patients, 132 (16.6%) received a single dose of intravenous cefotaxime and were compared to 119 (15%) who received multiple doses of oral cefpodoxime and 542 (68.3%) who received fluoroquinolones as monoprophylaxis. The overall incidence of severe infectious complications was 1.0% (n=8). No significant differences were observed between the three compared groups (0.8% vs. 0.8% vs. 1.1%, p=0.9). The overall rate of urosepsis was 0.3% and did not significantly differ between the three compared groups as well.

Conclusion

Monoprophylaxis with third generation cephalosporins was efficient in preventing severe infectious complications after prostate biopsy. Single intravenous dose of cefotaxime and multiday regimen of oral cefpodoxime showed a low incidence of infectious complications <1%. No differences were observed in comparison to fluoroquinolones.

Construction and Evaluation of a Sepsis Risk Prediction Model for Urinary Tract Infection

Background: Urinary tract infection (UTI) is one of the common causes of sepsis. However, nomograms predicting the sepsis risk in UTI patients have not been comprehensively researched. The goal of this study was to establish and validate a nomogram to predict the probability of sepsis in UTI patients.

Methods: Patients diagnosed with UTI were extracted from the Medical Information Mart for Intensive Care III database. These patients were randomly divided into training and validation cohorts. Independent prognostic factors for UTI patients were determined using forward stepwise logistic regression. A nomogram containing these factors was established to predict the sepsis incidence in UTI patients. The validity of our nomogram model was determined using multiple indicators, including the area under the receiver operating characteristic curve (AUC), correction curve, Hosmer-Lemeshow test, integrated discrimination improvement (IDI), net reclassification improvement (NRI), and decision-curve analysis (DCA).

Results: This study included 6,551 UTI patients. Stepwise regression analysis revealed that the independent risk factors for sepsis in UTI patients were congestive heart failure, diabetes, liver disease, fluid electrolyte disorders, APSIII, neutrophils, lymphocytes, red blood cell distribution width, urinary protein, urinary blood, and microorganisms. The nomogram was then constructed and validated. The AUC, NRI, IDI and DCA of the nomogram all showed better performance than traditional APSIII score. The calibration curve and Hosmer-Lemeshow test results indicate that the nomogram was well-calibrated. Improved NRI and IDI values indicate that our nomogram scoring system is superior to other commonly used ICU scoring systems. The DCA curve indicates that the DCA map of the nomogram has good clinical application ability.

Conclusion: This study identified the independent risk factors of sepsis in UTI patients and used them to construct a prediction model. The present findings may provide clinical reference information for preventing sepsis in UTI patients.

Novel Use of a Modified Triangular Prismatic Double-J Stent for 2- to 3-cm Renal Stones after One-Stage Retrograde Intrarenal Surgery

OBJECTIVES

To initially evaluate the outcomes of the modified triangular prismatic double-J (DJ) stent in the management of 2- to 3-cm renal stones after one-stage retrograde intrarenal surgery (RIRS).

METHODS

Patients with 2- to 3-cm renal stones who underwent one-stage RIRS with indwelling DJ stents were retrospectively evaluated. Eighty-eight patients who were placed the triangular prismatic DJ stents and 64 patients who received standard DJ stents were randomly included. The clinical characteristics and intraoperative and postoperative outcomes of the 2 groups were compared and analyzed.

RESULTS

The 2 groups had similar baseline characteristics. The urinary symptom score and pain score did not differ between groups (p > 0.05). The residual fragments of the 2 groups were similar 1 day after operation (p = 0.134). There was no significant difference in residual fragments in the lower calyx between groups at the time of stent removal (p = 0.834). The patients in the modified group had better spontaneous passage of residual fragments in the nonlower calyx than those in the standard group during the 2 weeks with the stents (p = 0.005). Fewer patients in the modified group had residual fragments (>4 mm) in the nonlower calyx (p = 0.026) and ureter (p = 0.010) than the patients with standard stents at the time of stent removal.

CONCLUSION

The indwelling triangular prismatic DJ stent is a safe and efficient treatment method. Patients with these stents had better spontaneous residual fragment passage than those with the standard DJ stents.

Systemic Inflammatory Response Syndrome Combined with Pre- and Postoperative White Blood Cell Ratio Is a Better Criterion to Identify Septic Shock Patients After Flexible Ureteroscopic Lithotripsy

Objective: To find out a better criterion to identify septic shock patients after flexible ureteroscopic lithotripsy (FUL). Materials and Methods: In total, 2364 patients who underwent the FUL procedure were enrolled in the study. The demographics and preoperative results of laboratory tests of the patients were collected. The postoperative white blood cell (WBC), systemic inflammatory response syndrome (SIRS), and quick sequential (sepsis-related) organ failure assessment score (qSOFA) were assessed 2 hours after FUL. The predictive efficacy was measured by sensitivity, specificity, positive and negative predictive value, and area under the receiver's operating characteristic curve (AUROC). Results: A total of 15 (0.63%) patients developed septic shock. There were 86 (3.64%) patients who were SIRS positive and 69 (2.92%) patients who were qSOFA positive. The pre- and postoperative WBC ratios in septic shock patients and normal patients were 2.50 ± 1.55 and 0.69 ± 0.24, respectively (p < 0.001). For sensitivity and negative predictive value, all reached 100%. For specificity, qSOFA was 97.70%, SIRS was 96.98%, and SIRS combining pre- and postoperative WBC ratio (the new criterion) was 99.79%. The new criterion had statistically significant higher specificity than SIRS or qSOFA (p < 0.001 for both), but when comparing SIRS and qSOFA, it had statistically insignificant specificity (p = 0.142). For positive predictive value, qSOFA was 21.73%, SIRS was 17.44%, and the new criterion was 75%. qSOFA and SIRS had similar AUROC (0.989 for qSOFA and 0.985 for SIRS), both lower than the new criterion (AUROC: 0.999). Conclusions: SIRS combined with pre- and postoperative WBC ratio has a much better specificity and positive predictive value than SIRS or qSOFA alone. It has 99.79% specificity and 75% positive predictive value, and as high as 100% sensitivity and negative predictive value.

Importance of the Hounsfield Unit Value Measured by Computed Tomography in the Differentiation of Hydronephrosis and Pyonephrosis

Objectives

To evaluate the efficacy of the non-contrast-enhanced computed tomography (NCECT) renal pelvis Hounsfield unit (HU) values in differentiating between the hydronephrosis and pyonephrosis in dilated urinary systems.

Materials and methods

Patients who underwent percutaneous nephrostomy (PN) due to urinary system obstruction in the last three years were retrospectively evaluated. Pyonephrosis and hydronephrosis groups were differentiated according to the clarity of percutaneous needle aspiration. The patients’ renal pelvic anteroposterior (AP) diameter, renal pelvic area, and mean HU values were measured on NCECT and compared between two groups.

Results

PN was performed on a total of 523 patients. The study included 159 patients and 214 renal units. Hydronephrosis was detected in 176 renal units and pyonephrosis in 38 renal units. No statistically significant difference was observed between the measured AP diameter and renal pelvic area in the two groups (28.45 ± 10.1 mm vs. 31.13 ± 14.4 mm, p = 0.36 and 658.51 ± 433.1 mm² vs. 755.14 ± 470.6 mm², p = 0.22, respectively). The mean HU value of the pyonephrosis group was significantly higher (2.30 ± 5.02 vs. 10.97 ± 6.68, p < 0.001). At the cut-off value of 8.46, HU had a sensitivity of 68.4% and specificity of 92.6% in the diagnosis of pyonephrosis.

Conclusions

It is possible to determine differential diagnosis between pyonephrosis and hydronephrosis easily and without additional cost by performing dilated renal pelvis HU measurements on NCECT.

A novel use of attenuation value (Hounsfield unit) in non-contrast CT: diagnosis of pyonephrosis in obstructed systems

PURPOSE

To evaluate the predictive value of attenuation value (HU) in renal pelvis urine for detecting renal pelvis urine culture (RPUC) positivity in obstructed urinary systems.

METHODS

The study group consisted of patients who had nephrostomy insertion performed because of obstructed system and suspicion of pyonephrosis and percutaneous nephrolithotomy (PCNL) patients who had obstructed calculi. Group 1 consisted of RPUC positive 28 patients during nephrostomy insertion or needle access in PCNL and group 2 consisted of 23 patients with negative RPUC. RPUC results and non-contrast computed tomography measurements [Hounsfield unit (HU)] were compared between group 1 and group 2. A cut-off value was determined for HU. All patients were grouped according to whether they were above or below this value.

RESULTS

The median HU calculated from the renal pelvis was - 8.5 (range - 29/- 1) and 10 (range- 4/+ 17) (p < 0.001) in group 1 and group 2, respectively. The cut-off value of HU that predicted positive RPUC was 0. Sensitivity and specificity of HU when considering this cut-off value were 100% and 96%, respectively (p < 0.001). Whereas RPUC positivity was found in 96.6% (28/29) of patients with HU < 0, there were no patients with HU > 0 where RPUC positivity was detected (p < 0.001).

CONCLUSION

In this cohort, we found that HU of the urine in the renal pelvis can be used to predict RPUC positivity.

Diagnostic and Prognostic Values of BMPER in Patients with Urosepsis following Ureteroscopic Lithotripsy

The present study aims to investigate the risk factors for urosepsis and the diagnostic and prognostic values of the bone morphogenetic protein endothelial cell precursor-derived regulator (BMPER) in patients with urosepsis following ureteroscopic lithotripsy. A total of 305 patients with unilateral ureteral obstruction caused by calculi were included in the study. Patients were divided into three groups, namely, high, medium, and low perfusion pressure groups. The serum C-reactive protein, procalcitonin, lactate (LAC), and BMPER were measured after operation. A logistic regression model was used to assess the risk factors for postoperative urosepsis. The relationships of BMPER with laboratory parameters were explored with a multiple linear regression model. Receiver operating characteristic (ROC) curves were used to diagnosis urosepsis. The cumulative incidence of the adverse events after operation was calculated and compared by log-rank test. Forty-five patients (14.8%) had an episode of urosepsis after operation. Irrigation pressure was an independent risk factor for urosepsis. LAC and sequential organ failure assessment (SOFA) were associated with BMPER after operation. The area under curve value of BMPER for urosepsis was 0.829 (95% confidence interval [CI], 0.773 to 0.884). Uroseptic patients with higher BMPER concentration exhibited more adverse outcome. BMPER possesses valuable discriminative capacity for urosepsis and is a strong predictor of adverse outcome in patients with urosepsis.

A nanofilter for fluidic devices by pillar-assisted self-assembly microparticles

We present a nanofilter based on pillar-assisted self-assembly microparticles for efficient capture of bacteria. Under an optimized condition, we simply fill the arrays of microscale pillars with submicron scale polystyrene particles to create a filter with nanoscale pore diameter in the range of 308 nm. The design parameters such as the pillar diameter and the inter-pillar spacing in the range of 5 μm-40 μm are optimized using a multi-physics finite element analysis and computational study based on bi-directionally coupled laminar flow and particle tracking solvers. The underlying dynamics of microparticles accumulation in the pillar array region are thoroughly investigated by studying the pillar wall shear stress and the filter pore diameter. The impact of design parameters on the device characteristics such as microparticles entrapment efficiency, pressure drop, and inter-pillar flow velocity is studied. We confirm a bell-curve trend in the capture efficiency versus inter-pillar spacing. Accordingly, the 10 μm inter-pillar spacing offers the highest capture capability (58.8%), with a decreasing entrapping trend for devices with larger inter-pillar spacing. This is the case that the 5 μm inter-pillar spacing demonstrates the highest pillar wall shear stress limiting its entrapping efficiency. As a proof of concept, fluorescently labeled Escherichia coli bacteria (E. coli) were captured using the proposed device. This device provides a simple design, robust operation, and ease of use. All of which are essential attributes for point of care devices.

A Hierarchical 3D Nanostructured Microfluidic Device for Sensitive Detection of Pathogenic Bacteria

Efficient capture and rapid detection of pathogenic bacteria from body fluids lead to early diagnostics of bacterial infections and significantly enhance the survival rate. We propose a universal nano/microfluidic device integrated with a 3D nanostructured detection platform for sensitive and quantifiable detection of pathogenic bacteria. Surface characterization of the nanostructured detection platform confirms a uniform distribution of hierarchical 3D nano-/microisland (NMI) structures with spatial orientation and nanorough protrusions. The hierarchical 3D NMI is the unique characteristic of the integrated device, which enables enhanced capture and quantifiable detection of bacteria via both a probe-free and immunoaffinity detection method. As a proof of principle, we demonstrate probe-free capture of pathogenic Escherichia coli (E. coli) and immunocapture of methicillin-resistant-Staphylococcus aureus (MRSA). Our device demonstrates a linear range between 50 and 10⁴ CFU mL^-1 , with average efficiency of 93% and 85% for probe-free detection of E. coli and immunoaffinity detection of MRSA, respectively. It is successfully demonstrated that the spatial orientation of 3D NMIs contributes in quantifiable detection of fluorescently labeled bacteria, while the nanorough protrusions contribute in probe-free capture of bacteria. The ease of fabrication, integration, and implementation can inspire future point-of-care devices based on nanomaterial interfaces for sensitive and high-throughput optical detection.

Chemoprophylaxis during transrectal prostate needle biopsy: critical analysis through randomized clinical trial

PURPOSE

To compare the efficacy of three chemoprophylaxis approaches in prevention of post-transrectal biopsy infectious complications (TBICs).

METHODS

Patients were randomly assigned to receive ciprofloxacin 3 days 500 mg B.I.D 3 days starting the night prior to biopsy (standard prophylaxis), augmented prophylaxis using ciprofloxacin and single preprocedure shot of 160 mg gentamicin IM (augmented prophylaxis) and rectal swab culture-based prophylaxis (targeted prophylaxis). Patients were assessed 2 weeks prior to biopsy, at biopsy and 2 weeks after. Primary end point was occurrence of post-TBICs that included simple UTI, febrile UTI or sepsis. Secondary end points were post-biopsy change in the inflammatory markers (TLC, ESR and CRP), unplanned visits, hospitalization and occurrence of fluoroquinolones resistance (FQ-R; bacterial growth on MacConkey agar plate with 10 μg/ml ciprofloxacin) in the fecal carriage of screened men.

RESULTS

Between April/2015 and January/2017, standard, augmented and targeted prophylaxes were given to 163, 166 and 167 patients, respectively. Post-TBICs were reported in 43 (26%), 13 (7.8%) and 34 (20.3%) patients following standard, augmented and targeted prophylaxes protocols, respectively (P = 0.000). Post-TBICs included UTI in 23 (4.6%), febrile UTI in 41 (8.2%) and sepsis in 26 (5.2%) patients. Significantly lower number of post-biopsy positive urine culture was depicted in the augmented group (P = 0.000). The number of biopsy cores was statistically different in the three groups (P = 0.004). On multivariate analysis, augmented prophylaxis had independently lower post-TBICs (OR 0.2, 95% CI 0.1-0.4, P = 0.000) when compared with the other two groups regardless of the number of biopsy cores taken (OR 1.07, 95% CI 0.95-1.17, P = 0.229). Post-biopsy hospitalization was needed in four (2%), one (0.6%) and ten (6%) patients following standard, augmented and targeted prophylaxes, respectively (P = 0.014). However, sepsis-related hospitalization was not statistically different. Post-biopsy changes in the inflammatory markers were significantly less in augmented prophylaxis (P < 0.05). FQ-R was depicted in 139 (83.2%) of the screened men.

CONCLUSION

Augmented prophylaxis with single-dose gentamicin is an effective and practical approach. Targeted prophylaxis might be reserved for cases with contraindication to gentamicin.

Clinical Presentations and Epidemiology of Urinary Tract Infections

Urinary tract infection (UTI) is one of the most common bacterial infections, and the incidence in women is much higher than in men. The diagnosis of a UTI can be made based on a combination of symptoms and a positive urine analysis or culture. Most UTIs are uncomplicated UTIs, defined as cystitis in a woman who is not pregnant, is not immunocompromised, has no anatomical and functional abnormalities of the urogenital tract, and does not exhibit signs of tissue invasion and systemic infection. All UTIs that are not uncomplicated are considered to be complicated UTIs. Differentiation between uncomplicated and complicated UTIs has implications for therapy because the risks of complications or treatment failure are increased for patients with a complicated UTI. Asymptomatic bacteriuria (ASB) is defined as the presence of a positive urine culture collected from a patient without symptoms of a UTI. Concerning the complicated UTI, it is possible to make a differentiation between UTI with systemic symptoms (febrile UTI) and UTI in a host, which carries an increased risk to develop complications of this UTI. Febrile UTIs are urosepsis, pyelonephritis, and prostatitis. A complicated host is defined as one that has an increased risk for complications, to which the following groups belong: men, pregnant women, immunocompromised patients, or those who have an anatomical or functional abnormality of the urogenital tract (e.g., spinal cord-injury patients, renal stones, urinary catheter).

Shock due to urosepsis: A multicentre study

INTRODUCTION

Urosepsis is a severe infection that can cause shock afterwards. The purpose of this study is to investigate the clinical and bacterial risk factors for shock in those cases with urosepsis caused by urinary tract infection in a multicentre study.

METHODS

Our study included 77 consecutive urosepsis cases from four hospitals. We examined factors such as patient characteristics, underlying disease, serum white blood cell (WBC) count, platelet count, C-reactive protein (CRP) level at the time of diagnosis of urosepsis, urinary tract occlusion, causative bacteria, and bacterial antibiotic susceptibilities. Statistical analyses were performed to assess the potential risk factors for shock during the clinical course of urosepsis by a multivariate analysis.

RESULTS

We had 38 male and 39 female patients aged 25-104 (median 73). Underlying diseases included cancers (n=22, 28.6 %) and diabetes mellitus (n=17, 22.1 %). Positive blood culture was seen in 74 cases; these involved 88 bacterial strains, of which Escherichia coli was the most common (34 strains, 38.6 %). There were 31 cases with shock (40.3 %) and multivariate analyses demonstrated that serum CRP was the only clinical risk factor for shock due to urosepsis.

CONCLUSIONS

Our study demonstrated that serum CRP was a risk factor for shock during urosepsis in a multicentre analysis. Further prospective studies with a greater number of patients are needed to draw more definitive conclusions.

Urosepsis--Etiology, Diagnosis, and Treatment

BACKGROUND

Sepsis is among the most common causes of death in Germany. Urosepsis accounts for 9-31% of all cases and has a mortality of 20-40%, which is low compared with that of sepsis in general. As the population ages, the incidence of urosepsis is likely to rise.

METHODS

Review of pertinent articles and guidelines retrieved by a selective search in PubMed.

RESULTS

Enterobacteria and Gram-positive organisms are the pathogens that most commonly cause urosepsis. The diagnosis can and must be made early on the basis of the typical clinical features, altered vital signs, and laboratory abnormalities, so that timely treatment can be initiated. 80% of cases are due to obstructive uropathy. The diagnostic evaluation includes physical examination, blood cultures, urinalysis, procalcitonin measurement, and ultrasonography. In one study, each additional hour of delay in the treatment of urosepsis with antibiotics was found to lower the survival rate by 7.6%. Antibiotics should be chosen in consideration of local resistance patterns and the expected pathogen spectrum.

CONCLUSION

Urologists, intensive care specialists, and microbiologists should all be involved in the interdisciplinary treatment of urosepsis. Patients' outcomes have improved recently, probably because of the frequent use of minimally invasive treatments to neutralize foci of infection. New biomarkers and new treatments still need to be validated in multicenter trials.

Urosepsis: Overview of the Diagnostic and Treatment Challenges

Urosepsis is defined as sepsis caused by an infection in the urogenital tract. In approximately 30% of all septic patients the infectious focus is localized in the urogenital tract, mainly due to obstructions at various levels, such as ureteral stones. Urosepsis may also occur after operations in the urogenital tract. In urosepsis, complete bacteria and components of the bacterial cell wall from the urogenital tract trigger the host inflammatory event and act as exogenous pyrogens on eukaryotic target cells of patients. A burst of second messenger molecules leads to several different stages of the septic process, from hyperactivity to immunosuppression. As pyelonephritis is the most frequent cause for urosepsis, the kidney function is therefore most important in terms of cause and as a target organ for dysfunction in the course of the sepsis.Since effective antimicrobial therapy must be initiated early during sepsis, the empiric intravenous therapy should be initiated immediately after microbiological sampling. For the selection of appropriate antimicrobials, it is important to know risk factors for resistant organisms and whether the sepsis is primary or secondary and community or nosocomially acquired. In addition, the preceding antimicrobial therapies should be recorded as precisely as possible. Resistance surveillance should, in any case, be performed locally to adjust for the best suitable empiric treatment. Treatment challenges arise from the rapid increase of antibiotic resistance in Gram-negative bacteria, especially extended-spectrum β-lactamase (ESBL)-producing bacteria. Treatment of urosepsis comprises four basic strategies I) supportive therapy (stabilizing and maintaining blood pressure), II) antimicrobial therapy, III) control or elimination of the complicating factor, and IV) specific sepsis therapy.

Digital Quantification of DNA Replication and Chromosome Segregation Enables Determination of Antimicrobial Susceptibility after only 15 Minutes of Antibiotic Exposure

Rapid antimicrobial susceptibility testing (AST) would decrease misuse and overuse of antibiotics. The "holy grail" of AST is a phenotype-based test that can be performed within a doctor visit. Such a test requires the ability to determine a pathogen's susceptibility after only a short antibiotic exposure. Herein, digital PCR (dPCR) was employed to test whether measuring DNA replication of the target pathogen through digital single-molecule counting would shorten the required time of antibiotic exposure. Partitioning bacterial chromosomal DNA into many small volumes during dPCR enabled AST results after short exposure times by 1) precise quantification and 2) a measurement of how antibiotics affect the states of macromolecular assembly of bacterial chromosomes. This digital AST (dAST) determined susceptibility of clinical isolates from urinary tract infections (UTIs) after 15 min of exposure for all four antibiotic classes relevant to UTIs. This work lays the foundation to develop a rapid, point-of-care AST and strengthen global antibiotic stewardship.

Flexible ureteroscopy versus laparoscopy for the treatment of patients who initially presented with obstructive pyelonephritis

Objective:

To compare the safety and effectiveness of flexible ureteroscopy (F-URS) with transperitoneal laparoscopic ureterolithotomy (TPLU) in cases of obstructive pyelonephritis secondary to large proximal ureteral stones.

Methods:

A series of 42 patients presenting with obstructive pyelonephritis due to proximal ureteral stones larger than 1.5 cm were included from April 2006 to February 2015 in this comparative study. After drainage of pyonephrosis and resolution of sepsis, 22 patients treated with TPLU (Group I), and 20 patients were treated with F-URS (Group II). Preoperative patient and stone characteristics, procedure-related parameters and clinical outcomes were assessed for each group.

Results:

It was seen that both methods were effective in the treatment of large proximal ureteral stones. However TPLU provided a higher stone- free rate (100% vs 80%. p=0.043) and lower retreatment rate. There was no difference between the groups for the operative time and complication rate. On the other hand, patients treated with F-URS had less postoperative pain (p=0.008), a shorter hospital stay (p<0.001) and a faster return to daily activities (p<0.001).

Conclusions:

The results of our study show that both F-URS and TPLU are safe and effective surgical procedures for treatment of large proximal ureteral stones after controlling obstructive pyelonephritis. However, TPLU has a higher stone-free rate with comparable operating time and complication rate as compared to F-URS. On the other hand F-URS has the advantages of less postoperative pain, shorter hospital stay and faster return to daily activities.

Comparison of the clinical efficacy and safety of retroperitoneal laparoscopic ureterolithotomy and ureteroscopic holmium laser lithotripsy in the treatment of obstructive upper ureteral calculi with concurrent urinary tract infections

The aim of this study is to compare the clinical efficacy and safety of retroperitoneal laparoscopic ureterolithotomy (RPLU) and ureteroscopic holmium laser lithotripsy (UHLL) as two minimally invasive procedures in managing obstructive upper ureteral calculi with concurrent urinary tract infections (UTI). The retrospective study included 189 patients who underwent unilateral obstructive upper ureteral stones with concurrent UTI from January 2007 to November 2014 at our institution. Patients received RPLU (81 cases) or UHLL (108 cases). All patients received preoperative anti-infection treatment (indwelling ureteral stent and/or preoperative antibiotics). Collected data, including sex, age, stone size, success rate, operation duration, post-operation hospitalization time, and post-operation complications, were compared. All patients were followed up for more than 6 months after surgeries, and no ureterostenosis occurred. The study included 189 patients, 41 (21.7 %) females and 148 (78.3 %) males with a medium age of 52 years (range 22-81 years). All surgeries were successfully performed without conversion to open surgery. Stone size in the RPLU group was larger than that of the UHLL group (16.1 ± 1.4 vs. 10.4 ± 1.6 mm, P = 0.012). Operative duration (P = 0.009) and hospitalization time (P < 0.001) in the UHLL group were significantly shorter than those in the RPLU group, whereas stone clearance rate was significantly higher in the RPLU group (100 vs. 88.9 %, P = 0.002). Of note, postoperative fever was more common in patients treated with UHLL (15 cases) versus RPLU (4 cases) (13.9 vs. 4.9 %, P = 0.043). Moreover, in the UHLL group, three patients without a preoperative indwelling ureteral stent were complicated with sepsis, which was not seen in RPLU group. In our study, the safety and stone clearance rate of RPLU are better than those of UHLL in the treatment of unilateral upper ureteric calculi with concurrent UTI. Preoperative antibiotics and indwelling ureteral stent may reduce the risk of postoperative infections.

Strengths and Limitations of Model Systems for the Study of Urinary Tract Infections and Related Pathologies

Urinary tract infections (UTIs) are some of the most common bacterial infections worldwide and are a source of substantial morbidity among otherwise healthy women. UTIs can be caused by a variety of microbes, but the predominant etiologic agent of these infections is uropathogenic Escherichia coli (UPEC). An especially troubling feature of UPEC-associated UTIs is their high rate of recurrence. This problem is compounded by the drastic increase in the global incidence of antibiotic-resistant UPEC strains over the past 15 years. The need for more-effective treatments for UTIs is driving research aimed at bettering our understanding of the virulence mechanisms and host-pathogen interactions that occur during the course of these infections. Surrogate models of human infection, including cell culture systems and the use of murine, porcine, avian, teleost (zebrafish), and nematode hosts, are being employed to define host and bacterial factors that modulate the pathogenesis of UTIs. These model systems are revealing how UPEC strains can avoid or overcome host defenses and acquire scarce nutrients while also providing insight into the virulence mechanisms used by UPEC within compromised individuals, such as catheterized patients. Here, we summarize our current understanding of UTI pathogenesis while also giving an overview of the model systems used to study the initiation, persistence, and recurrence of UTIs and life-threatening sequelae like urosepsis. Although we focus on UPEC, the experimental systems described here can also provide valuable insight into the disease processes associated with other bacterial pathogens both within the urinary tract and elsewhere within the host.

Prognostic Value of Adrenomedullin and Natriuretic Peptides in Uroseptic Patients Induced by Ureteroscopy

The aim of this paper is to investigate whether urosepsis is related to irrigation pressure of ureteroscopy (URS) and evaluate the prognostic value of adrenomedullin (ADM) and atrial and brain natriuretic peptides (ANP and BNP) in URS-induced uroseptic patients. From July 2008 to October 2013, we enrolled 332 patients with untreated unilateral ureteral obstruction (UUO). The UUO group included three subgroups of, respectively, 118, 132, and 82 patients who underwent URS under intermittent stable irrigation pressure of, respectively, 80, 120, and 160 mmHg. The plasma concentrations of ADM, ANP, and BNP were measured in all subjects. URS was performed for all UUO patients; the values of the three peptides were measured again after URS. Irrigation pressure and stone size were independent risk factors of urosepsis. After URS, the plasma concentrations of ADM, ANP, and BNP were significantly higher in uroseptic patients. Moreover, the concentrations were significantly higher depending on the disease severity. Plasma concentrations of the three peptides were correlated with plasma ET concentration in the uroseptic patients. The areas under receiver operating characteristic (ROC) curve of ADM, ANP, and BNP for predicting urosepsis were 0.811, 0.728, and 0.764, respectively. In conclusion, ADM, along with ANP and BNP, is valuable for prognosis in urosepsis secondary to URS which is associated with irrigation pressure.

Urinary obstruction is an important complicating factor in patients with septic shock due to urinary infection

OBJECTIVE

Urinary tract infection (UTI) is a common cause of severe sepsis, and anatomic urologic obstruction is a recognized factor for complicated disease. We aimed to identify the incidence of urinary obstruction complicating acute septic shock and determine the characteristics and outcomes of this group.

METHODS

Patients prospectively enrolled in a sepsis treatment pathway registry between October 2013 and July 2014 were reviewed for the diagnosis of UTI. Standardized medical record review was performed to confirm sepsis due to UTI and determine clinical variables including the presence of anatomic urinary obstruction. Patients with septic shock due to UTI with obstruction were compared with those without obstruction. The primary outcomes were incidence of urinary obstruction and hospital mortality.

RESULTS

Among 1084 registry enrollees, 209 (19.2%) met inclusion criteria for the study. Acute anatomic obstruction was identified in 22 (10.5%) patients. Hospital mortality in patients with obstruction was 27.3% compared with 11.2% in patients without obstruction (absolute difference of 16.1%; P = .03; 95% confidence interval [CI], 1.2%-30.9%). Hospital length of stay among survivors was 12.8 days compared with 8.3 days (absolute difference of 4.5 days; P = .04; 95% CI, 0.2-8.8 days). History of urinary stone disease was independently associated with obstruction (odds ratio, 5.6; 95% CI, 2.2-14.3).

CONCLUSIONS

Approximately 1 in 10 patients presenting with septic shock due to a urinary source is complicated by anatomic urinary obstruction. These patients have significantly higher mortality compared with patients without obstruction. Early imaging of patients with septic shock due to suspected urinary source should be considered to identify obstruction requiring emergency intervention.

After urgent drainage of an obstructed kidney by internal ureteric stenting; is ureteroscopic stone extraction always needed?

OBJECTIVES

To assess the probability of spontaneous stone passage and its predictors after drainage of obstructed kidney by JJ stent, as insertion of an internal ureteric stent is often used for renal drainage in cases of calcular ureteric obstruction.

PATIENTS AND METHODS

Between January 2011 and June 2013, patients for whom emergent drainage by ureteric stents were identified. The patients' demographics, presentation, and stone characteristics were reviewed. The primary endpoint for this study was stone-free status at the time of stent removal, where all patients underwent non-contrast spiral computed tomography (NCCT) before stent removal. Ureteroscopic stone extraction was performed for CT detectable ureteric stones at the time of stent removal. Potential factors affecting the need for ureteroscopic stone extraction at the time of stent removal were assessed using univariate and multivariate statistical analyses.

RESULTS

Emergent ureteric stents were undertaken in 196 patients (112 males, 84 females) with a mean (SD) age of 53.7 (16.2) years, for renal obstruction drainage. At the time of stent removal, 83 patients (42.3%) were stone free; with the remaining 113 patients (57.7%) undergoing ureteroscopic stone extraction. On multivariate analysis, stone width [odds ratio (OR) 15.849, 95% confidence interval (CI) 2.83; P = 0.002) and radio-opaque stones (OR 12.035, 95% CI 4.65; P < 0.001) were independent predictors of the need for ureteroscopic stone extraction at the time of stent removal.

CONCLUSION

Spontaneous ureteric stone passage is possible after emergent drainage of an obstructed kidney by ureteric stenting. Stone opacity, larger stone width, and positive preoperative urine culture are associated with a greater probability of requiring ureteroscopic stone extraction after emergent drainage by ureteric stenting.

The yin-yang driving urinary tract infection and how proteomics can enhance research, diagnostics, and treatment

Bacterial urinary tract infections (UTIs) afflict millions of people worldwide both in the community and the hospital setting. The onset, duration, and severity of infection depend on the characteristics of the invading pathogen (yin), as well as the immune response elicited by the infected individual (yang). Uropathogenic Escherichia coli (UPEC) account for the majority of UTIs, and extensive investigations by many scientific groups have elucidated an elaborate pathogenic UPEC life cycle, involving the occupation of extracellular and intracellular niches and the expression of an arsenal of virulence factors that facilitate niche occupation. This review will summarize the current knowledge on UPEC pathogenesis; the host immune responses elicited to combat infection; and it will describe proteomics approaches used to understand UPEC pathogenesis, as well as drive diagnostics and treatment options. Finally, new strategies are highlighted that could be applied toward furthering our knowledge regarding host-bacterial interactions during UTI.

Risk Factors for Development of Septic Shock in Patients with Urinary Tract Infection

INTRODUCTION

Severe sepsis and septic shock are associated with substantial mortality. However, few studies have assessed the risk of septic shock among patients who suffered from urinary tract infection (UTI).

MATERIALS AND METHODS

This retrospective study recruited UTI cases from an acute care hospital between January 2006 and October 2012 with prospective data collection.

RESULTS

Of the 710 participants admitted for UTI, 80 patients (11.3%) had septic shock. The rate of bacteremia is 27.9%; acute kidney injury is 12.7%, and the mortality rate is 0.28%. Multivariable logistic regression analyses indicated that coronary artery disease (CAD) (OR: 2.521, 95% CI: 1.129-5.628, P = 0.024), congestive heart failure (CHF) (OR: 4.638, 95% CI: 1.908-11.273, P = 0.001), and acute kidney injury (AKI) (OR: 2.992, 95% CI: 1.610-5.561, P = 0.001) were independently associated with septic shock in patients admitted with UTI. In addition, congestive heart failure (female, OR: 4.076, 95% CI: 1.355-12.262, P = 0.012; male, OR: 5.676, 95% CI: 1.103-29.220, P = 0.038, resp.) and AKI (female, OR: 2.995, 95% CI: 1.355-6.621, P = 0.007; male, OR: 3.359, 95% CI: 1.158-9.747, P = 0.026, resp.) were significantly associated with risk of septic shock in both gender groups.

CONCLUSION

This study showed that patients with a medical history of CAD or CHF have a higher risk of shock when admitted for UTI treatment. AKI, a complication of UTI, was also associated with septic shock. Therefore, prompt and aggressive management is recommended for those with higher risks to prevent subsequent treatment failure in UTI patients.

Rapid electrochemical phenotypic profiling of antibiotic-resistant bacteria

Rapid phenotyping of bacteria to identify drug-resistant strains is an important capability for the treatment and management of infectious disease. At present, the rapid determination of antibiotic susceptibility is hindered by the requirement that, in existing devices, bacteria must be pre-cultured for 2-3 days to reach detectable levels. Here we report a novel electrochemical approach that achieves rapid readout of the antibiotic susceptibility profile of a bacterial infection within one hour. The electrochemical reduction of a redox-active molecule is monitored that reports on levels of metabolically-active bacteria. Bacteria are captured in miniaturized wells, incubated with antimicrobials and monitored for resistance. This electrochemical phenotyping approach is effective with clinically-relevant levels of bacteria, and provides results comparable to culture-based analysis. Results, however, are delivered on a much faster timescale, with resistance profiles available after a one hour incubation period.

Retrograde ureteric stent insertion in the management of infected obstructed kidneys

OBJECTIVES

To quantify the outcomes of retrograde ureteric stenting in the setting of infected hydronephrosis secondary to ureteric calculi.

PATIENTS AND METHODS

Prospective analysis of all patients over a 15-month period admitted with infected obstructed kidneys secondary to ureteric calculi. Inclusion criteria were based on clinical evidence of systemic inflammatory response syndrome (SIRS) and radiological evidence of obstructing ureteric calculi. Outcome measures included success of procedure, admission to intensive care unit (ICU), length of hospital stay, morbidity, and all-cause mortality during hospital admission.

RESULTS

In all, 52 patients were included. Success of retrograde ureteric stenting was 98%. In all, 17% of patients required an ICU admission, with a post ureteric instrumentation ICU admissions rate of 6%. The mean white cell count and serum creatinine improved significantly after the procedure. Major complication rate included septic shock 6%, but there were no episodes of major haemorrhage and no deaths.

CONCLUSION

Retrograde ureteric stenting is safe and effective in infected obstructed kidneys with results comparable to percutaneous nephrostomy tube insertion. Post instrumentation ICU admissions occur in 6% of retrograde stentings.

Risk factors for severe sepsis in community-onset bacteraemic urinary tract infection: impact of antimicrobial resistance in a large hospitalised cohort

OBJECTIVE

To determine risks factors associated with severe sepsis or septic shock (SS) at admission in patients with community-onset bacteraemic urinary tract infection (CO-BUTI) including the impact of multidrug-resistant (MDR) bacteria.

METHODS

We analysed a prospective cohort of all consecutive episodes of CO-BUTI requiring hospitalisation in 8 tertiary hospitals of Spain between October 2010 and June 2011.

RESULTS

Of an overall of 525 CO-BUTI episodes, 175 (33%) presented with SS at admission. MDR bacteria were isolated in 29% (51/175) of episodes with SS and in 33% (117/350) of those without SS (p = 0.32). The main MDR microorganism was Escherichia coli in both groups (25% and 28% respectively). Independent risk factors associated with SS at admission were: having fatal underlying conditions, McCabe score II/III (OR 1.90; 95%CI 1.23-2.92; p = 0.004), presence of an indwelling urethral catheter (OR 3.01; 95%CI 1.50-6.03; p = 0.002) and a history of urinary tract obstruction (OR 1.56; 95%CI 1.03-2.34; p = 0.03). After considering interactions, indwelling urethral catheters were a risk factor only for patients without fatal underlying conditions.

CONCLUSIONS

SS at hospital admission occurred in a third of CO-BUTI. Mainly host factors, and not the causative microorganisms or antimicrobial resistance patterns had an impact on the presence of SS.

Association of interleukin-10 gene promoter polymorphisms with susceptibility to acute pyelonephritis in children

Interleukin-10 (IL-10) is a potent inhibitor of leukocyte chemotaxis, bacterial killing in phagocytes and synthesis of pro-inflammatory cytokines and chemokines, and recent studies have suggested an important role for this immunoregulatory cytokine in the pathogenesis of urinary tract infections (UTIs). Therefore, the gene encoding IL-10 (IL10) is an attractive candidate for association studies attempting to identify susceptibility genes conferring risk of UTIs. In this case-control study, we aimed to investigate the association of single nucleotide polymorphisms (SNPs) in the promoter region of IL10 with acute pyelonephritis in the Slovak population. Polymerase chain reaction with sequence-specific primers was used to analyse IL10 -1082A/G (rs1800896), -819C/T (rs1800871) and -592C/A (rs1800872) SNPs in 147 children with acute pyelonephritis and 215 healthy controls. Comparison of patients with healthy controls using the logistic regression analysis revealed significantly increased risk of developing recurrent attacks of acute pyelonephritis for -1082 G allele in a dominant genetic model GG (GG + AG vs. AA, P = 0.019, odds ratio (OR) = 2.26). A similar tendency was also found when the recurrent acute pyelonephritis subgroup was compared to episodic pyelonephritis cases (GG + AG vs. AA, P = 0.009, OR = 3.38). In conclusion, our results suggest that IL10 -1082 A/G SNP is a susceptibility factor for development of recurrent attacks of acute pyelonephritis.

Seven hours to adequate antimicrobial therapy in urosepsis using isothermal microcalorimetry

Urosepsis can progress toward severe sepsis, septic shock, and, ultimately, death. Rapid antimicrobial susceptibility testing is crucial to decrease mortality and morbidity. This report shows that isothermal microcalorimetry can provide an antibiogram within 7 h with a sensitivity of 95% and specificity of 91% using Vitek-2 system as a reference.

Clinical factors associated with shock in bacteremic UTI

PURPOSE

Urinary tract infection (UTI) often causes bacteremia, resulting in shock. The purpose of this study is to investigate urological bacteremia and bacteremia shock cases and seek for the clinical factors associated with urological bacteremic shock.

METHODS

Seventy consecutive cases with bacteremia caused by UTI from the Department of Urology, Kobe University Hospital were studied. These cases were diagnosed from 2000 to 2010 and had full data available for analysis. We investigated the potential clinical factors associated with bacteremic shock (systolic blood pressure ≤ 90 mmHg with UTI), including: (1) the number of basal general diseases (such as diabetes, malignancy, immune diseases, heart diseases, liver diseases, and kidney diseases), (2) causative bacteria, (3) antibiotics and therapeutic intervention, (4) gram-negative bacteria, (5) resistance to imipenem (which is often used in this infection), and (6) serum white blood cell counts and C-reactive protein (CRP) at the time of diagnosis of bacteremic UTI.

RESULTS

A total of 81 causative bacteria were isolated: 42 cases were gram-negative and 39 were gram-positive bacteria. In detail, Escherichia coli was the most common, followed by Methicillin-resistant Staphylococcus aureus. The comparison data revealed that urological bacteremic shock cases had significantly increased CRP (p < 0.001). Our univariate analyses showed indwelling urinary tract catheters (p = 0.02) as a significant clinical factor associated with urological bacteremic shock and multivariate analyses showed that the presence of indwelling urinary tract catheters before UTI was a significant clinical factor associated with urological bacteremic shock (p = 0.04).

CONCLUSIONS

Indwelling urinary catheters before UTI and high CRP were clinical factors associated with urological bacteremic shock. This result should be considered during decision-making for UTI treatments in high risk cases or urological bacteremia cases.

Increased Incidence of Escherichia Coli Bacteremia Post-Christchurch Earthquake 2011: Possible Associations

Introduction

Earthquakes are natural events that contribute to the transmission of infectious diseases. The aim of this research was to determine whether the observed increase in Escherichia coli (E. coli) bloodstream infections (BSI) during the period March-June 2011 was associated with the February 2011 Christchurch earthquake.

Methods

Descriptive statistics and spatial distributional analysis techniques were used to quantify patients with E. coli BSI in 2009-2011.

Results

E. coli BSI acquired from non-catheter related urinary tract infection (UTI) was the predominant infection type, with the greatest increase during March-June 2011. Bacteremia incidence was higher in females than in males for 2009-2011. In 2011, the median age of patients was 75 years, and an increase in males acquiring such infections was noted. Spatial distributional analysis failed to show direct association between bacteremia cases and liquefaction-related land damage or drinking water contamination. A higher incidence of E. coli BSI post-earthquake in the eastern suburbs, which tend towards a higher level of socioeconomic deprivation, was observed.

Conclusion

A number of possible factors contributing to the observed increase in E. coli BSI acquired from UTI in 2011 were considered. Individuals with higher deprivation indices, males and the elderly may be particularly vulnerable to the effects of a major disaster with subsequent breakdown of infrastructure. These findings have important implications in natural disaster situations, and justify development of strategies to identify UTI and pyelonephritis risk factors and to manage E. coli bacteremia incidence rates.

SchousboeM, LyndsJ, AmbroseC. Increased incidence of Escherichia Coli bacteremia post-Christchurch earthquake 2011: possible associations. Prehosp Disaster Med. 2013;28(3):1-8.

Prevalence and pathogenesis of extended-spectrum beta-lactamase producing Escherichia coli causing urinary tract infection in hospitalized patients

A total of 296 E. coli strains isolated from hospitalized patients with urinary tract infection were included in this study. These strains were tested for their resistance to 22 antimicrobial drugs and the presence of ESBLs genes coding for TEM, SHV, OXA, and CTX-M. We further characterized them for their interaction with a renal cell line (A-498) and a gastrointestinal cell line (Caco-2). Strains were also typed using a combination of RAPD-PCR, PhP-typing and phylogenetic grouping. Only eight strains (2.7 %) were confirmed as ESBLs producers. The most common clonal type contained 35 isolates and only two of them were ESBLs producers and both showed a high degree of adhesion to both cell lines but only one was able to translocate in Caco-2 cells. These strains belonged to phylogenetic group B2, were resistant to nine antibiotics and carried CTX-M-type of ESBL. The remaining six strains belonged to single clones with different phylogenetic groups and ESBL genotypes and were resistant to between 12 and 15 antibiotics. They also showed a high rate of adhesion to A-498 cells (19 ± 2 to 35 ± 3 CFU/cell) and all translocated in this cell line. The rate of adhesion of ESBL-producing strains to Caco-2 cells (11 ± 3.4 CFU/cell) was significantly lower than A-498 cells (26 ± 8 CFU/cell) (p = 0.0002) and only four of them translocated in Caco-2 cells. Our results suggest that the ESBL-producing clones of E. coli have a potential to translocate and cause septicemia in hospitalized patients with UTI.