Early and rapid prediction of postoperative infections following percutaneous nephrolithotomy in patients with complex kidney stones

OBJECTIVES

To obtain more accurate and rapid predictors of postoperative infections following percutaneous nephrolithotomy (PCNL) in patients with complex kidney stones, and provide evidence for early prevention and treatment of postoperative infections.

PATIENTS AND METHODS

A total of 802 patients with complex kidney stones who underwent PCNL, from September 2016 to September 2017, were recruited. Urine tests, urine cultures (UCs) and stone cultures (SCs) were performed, and the perioperative data were prospectively recorded.

RESULTS

In all, 19 (2.4%) patients developed postoperative urosepsis. A multivariate logistic regression analysis revealed that an operating time of ≥100 min, urine test results with both positive urine white blood cells (WBC+) and positive urine nitrite (WBC+NIT+), positive UCs (UC+), and positive SCs (SC+) were independent risk factors of urosepsis. The incidence of postoperative urosepsis was higher in patients with WBC+NIT+ (10%) or patients with both UC+ and SC+ (UC+SC+; 8.3%) than in patients with negative urine test results or negative cultures (P < 0.01). Preoperative WBC+NIT+ was predictive of UC+SC+, with an accuracy of >90%. The main pathogens found in kidney stones were Escherichia coli (44%), Proteus mirabilis (14%) and Staphylococcus (7.4%); whilst the main pathogens found in urine were E. coli (54%), Enterococcus (9.4%) and P. mirabilis (7.6%). The incidence of E. coli was more frequent in the group with urosepsis than in the group without urosepsis (P < 0.05).

CONCLUSIONS

WBC+NIT+ in preoperative urine tests could be considered as an early and rapid predictor of UC+SC+ and postoperative urosepsis. Urosepsis following PCNL was strongly associated with E. coli infections in patients with complex kidney stones.

Optimal Urine Culture Diagnostic Stewardship Practice- Results from an Expert Modified-Delphi Procedure

BACKGROUND

Urine cultures are nonspecific for infection and often lead to misdiagnosis of urinary tract infection and unnecessary antibiotics. Diagnostic stewardship is a set of procedures that modifies test ordering, processing, and reporting in order to optimize diagnosis and downstream treatment. This study aimed to develop expert guidance on best practices for urine culture diagnostic stewardship.

METHODS

A RAND-modified Delphi approach with a multidisciplinary expert panel was used to ascertain diagnostic stewardship best practices. Clinical questions to guide recommendations were grouped in three thematic areas (ordering, processing, reporting) in practice settings of emergency department, inpatient, ambulatory, and long-term care. Fifteen experts ranked recommendations on a 9-point Likert scale. Recommendations on which the panel did not reach agreement were discussed in a virtual meeting, and a then second round of ranking by email was completed. After secondary review of results and panel discussion, a series of guidance statements was developed.

RESULTS

165 questions were reviewed with the panel reaching agreement on 104, leading to 18 overarching guidance statements. The following strategies were recommended to optimize ordering urine cultures: requiring documentation of symptoms, alerts to discourage ordering in the absence of symptoms, and cancelling repeat cultures. For urine culture processing, conditional reflex urine cultures and urine white blood cell as criteria were supported. For urine culture reporting, appropriate practices included nudges to discourage treatment under specific conditions and selective reporting of antibiotics to guide therapy decisions.

CONCLUSIONS

These 18 guidance statements can optimize use of the imperfect urine culture for better patient outcomes.

Knowledge and Practices of Physicians and Nurses Related to Urine Cultures in Catheterized Patients: An Assessment of Adherence to IDSA Guidelines

BACKGROUND

A positive urine culture often drives initiation of antimicrobials even in the absence of symptoms. Our objectives were to evaluate the knowledge and practice patterns related to ordering urine cultures in patients with indwelling urinary catheters.

METHODS

We performed chart reviews of catheter-associated urinary tract infections (CAUTIs) at our academic health care system between October 1, 2015, and September 30, 2017, to assess practice patterns related to the assessment of potential CAUTIs. Following this, we surveyed physicians and nurses about indications for ordering urine cultures in catheterized patients between January 11, 2018, and April 17, 2018. The accuracy of these indications was assessed based on Infectious Diseases Society of America CAUTI and asymptomatic bacteriuria guidelines.

RESULTS

On chart review, we identified 184 CAUTIs in 2 years. In 159 episodes (86%), urine cultures were ordered inappropriately. In 114 episodes (62%), CAUTI criteria were met by "pan-culturing" rather than symptom-directed testing. Twenty cases (11%) experienced partial or delayed management of other infections, drug adverse events, and Clostridioides difficile infections (CDIs). On our survey, we received 405 responses, for a response rate of 45.3%. Mean scores varied by occupation and level of training. Nurses were more likely than physicians to consider change in appearance (61% vs 23%; P < .05) and odor (74% vs 42%; P < .05) of urine as indications to order urine cultures.

CONCLUSIONS

Our data reveal specific knowledge gaps among physicians and nurses related to ordering urine cultures in catheterized patients. The practice of pan-culturing and inappropriate urine culture orders may contribute to overdiagnosis of surveillance CAUTIs, delay in diagnosis of alternative infections, and excess CDIs.

Microbiological profile of urinary tract infections in a tertiary medical facility in Western Mexico: An update

Urinary tract infections (UTIs) are one of the most important issues in modern medicine. In developing countries, the use of antibiotics is a common practice, and due to this, antibiotic resistance has increased. The objective of this research was to update and report on the microbiological profile of urinary tract infections based on the number of positive urine cultures (UCs), resistance, sensitivity, and the prevalence of bacterial strains. The results were obtained from the database of a tertiary medical facility in Western Mexico. The number of positive UCs was 1769 from inpatients and outpatients who were users of medical services in the hospital from January to December of 2017. The most commonly isolated microorganism was E. coli, with 1225 cases, of which 603 (49.2%) were ESBL (Extended-Spectrum Beta-Lactamase-producing bacteria) strains. The resistance rate of nitrofurantoin was 36.6%, and meropenem showed the most promising results with a resistance rate of only 7.1%. Resistances to quinolones and cephalosporins among the isolates investigated were 51%-67%. Based on our results, it is necessary to increase controls and to improve management protocols in order to achieve better medical practices by reducing antibiotic resistance.

Bacterial species cultured after electrofulguration in women with a history of antibiotic-recalcitrant urinary tract infections frequently compare with pre-fulguration findings: a pilot study

Electrofulguration (EF) of areas of chronic cystitis in women with antibiotic-recalcitrant recurrent urinary tract infections (RUTIs) can result in improvement of their urinary tract infections (UTIs). We compared urine culture (UC) findings in patients before and after EF, as well as how they vary with cystitis stage at the time of EF, to evaluate for persistent species. After obtaining institutional review board approval, we retrospectively reviewed a prospectively maintained database of EF patients for those with positive UC findings in the 3-6 months preceding EF. Patient pre-EF UC was then compared with first positive UC after EF prompted by a new symptomatic UTI episode, with the hypothesis that the same species will be identified before and after EF. Exclusion criteria included UC from outside institution, neurogenic bladder, and need for catheterization. Ninety-nine women with pre- or post-EF UC-recorded organisms met the study criteria. The median age was 65 years (interquartile range 64-74), with a median time to first positive culture following fulguration of 9.7 months. For 26 patients with positive cultures both pre- and post-EF, the same organism was present in both cultures in 73% of the patients, with predominantly Escherichia coli. EF was effective at reducing the rate of UTIs in this population. For women undergoing EF for antibiotic-recalcitrant RUTIs and associated chronic cystitis lesions, 73% of those with a UC obtained at the time of a first symptomatic recurrent UTI episode post-EF expressed the same organism as before EF. Further study is needed to better understand the evolution of the microbiome post-EF.IMPORTANCEAmong women who experience a recurrent urinary tract infection after a fulguration procedure on areas of chronic cystitis in their bladder, there are no data available on whether the bacterial species found in urine cultures are the same or different from those present before fulguration. By removing the inflamed surface layer of cystitis during fulguration, it is possible that the procedure unmasks deep-seated bacteria. The bacterial kingdom in the bladder wall of these chronically infected women may be different from what is expressed sporadically in urine cultures. Confirming prior studies, we found that fulguration in women with antibiotic-recalcitrant recurrent urinary tract infections and cystitis lesions was effective at reducing the rate of urinary tract infections. At the time of a first symptomatic recurrent UTI episode post-fulguration, 73% expressed the same organism in urine culture as before fulguration. Further study is needed to better understand the evolution of the microbiome post-EF. This article evaluates persistent infections after electrofulguration of areas with chronic cystitis in post-menopausal women with antibiotic-recalcitrant recurrent urinary tract infections. Pre-fulguration urine cultures were compared with the first positive urine culture prompted by a new symptomatic UTI episode after electrofulguration, with the hypothesis that the same species will be identified before and after the fulguration procedure. Electrofulguration was effective at reducing the rate of UTIs in this population. However, 73% of those with a urine culture obtained at the time of a first symptomatic recurrent UTI episode post-electrofulguration expressed the same organism (predominantly Escherichia coli) as before the fulguration procedure. Further study is needed to better understand the evolution of the microbiome after electrofulguration.

Comparison of the APAS Independence Automated Plate Reader System with the Manual Standard of Care for Processing Urine Culture Specimens

Urine cultures are among the highest-volume tests in clinical microbiology laboratories and usually require considerable manual labor to perform. We evaluated the APAS Independence automated plate reader system and compared it to our manual standard of care (SOC) for processing urine cultures. The APAS device provides automated image interpretation of urine culture plate growth and sorts those images that require further evaluation. We examined 1,519 specimens over a 4-month period and compared the APAS growth interpretations to our SOC. We found that 72 of the 1,519 total specimens (4.74%) had growth discrepancies, where these specimens were interpreted differently by the APAS and the technologist, which required additional evaluation of plate images on the APAS system. Overall, there were 56 discrepancies in pathogen identification, which were present in 3.69% of the cultures. An additional pathogen was uncovered in a majority of these discrepancies; 12 (21.4%) identified an additional pathogen for the SOC, and 40 (71.4%) identified an additional pathogen for the APAS workflow. We found 214 (2.69%) antimicrobial susceptibility test (AST) discrepancies; 136 (1.71%) minor errors (mEs), 41 (0.52%) major errors (MEs), and 36 (0.45%) very major errors (VMEs). Many of the MEs and VMEs occurred in only a small subset of 13 organisms, suggesting that the specimen may have had different strains of the same pathogens with differing AST results. Given the significant labor required to perform urine cultures, the APAS Independence system has the potential to reduce manual labor while maintaining the identity and AST results of urinary pathogens. IMPORTANCE Urine cultures are among the highest-volume tests performed in clinical microbiology facilities and require considerable manual labor to perform. We compared the results of our manual SOC workflow with that of the APAS Independence system, which provides automated image interpretation and sorting of urine culture plates based on growth. We examined 1,519 urine cultures processed using both workflows and found that only 4.74% had growth pattern discrepancies and 3.69% pathogen identification discrepancies. There was substantial agreement in AST results between workflows, with only 2.69% having discrepancies. Only 1.71% of the ASTs had mEs, 0.52% had MEs, and 0.45% had VMEs, with most of the MEs and VMEs belonging to a small subset of organisms. The APAS system significantly decreased manual urine culture processing, while providing similar results to the SOC. As such, incorporating such automation into laboratory workflows has the potential to significantly improve efficiency.

Microbiological profile and antibiotic susceptibility profile of urine cultures in patients with spinal cord injury-retrospective study

Background

Urinary tract infections (UTIs) and urinary tract colonizations (UTCs) are common in patients with spinal cord injury (SCI). The aim of this study was to characterize the microbiological profile of urine cultures in patients with SCI and to determine the antibiotic susceptibility profile of most common microorganisms, to track antibiotic resistance and facilitate empiric antibiotic selection.

Methods

A retrospective observational study was conducted on 235 urine culture results of 29 patients with SCI followed at a Physical and Rehabilitation Medicine outpatient consultation between January 2016 and April 2024. Data regarding sociodemographics, cause of SCI, American Spinal Injury Association Impairment Scale classification, voiding method, microbiological urine culture profile, and antimicrobial resistance were collected and statistically analyzed. UTIs (defined as bacteriuria, leukocyturia, positive urine culture, and new onset of signs and/or symptoms) were differentiated from UTCs.

Results

Patients were mostly men (86%), with a mean age of 52.1 years. UTIs occurred in 134 specimens (57%) and UTCs in 101 (43%). In both UTIs and UTCs, microbiological agents were mostly bacteria; Escherichia coli was the commonest overall (39%) and more frequent in indwelling catheterization (in UTIs) and intermittent self-catheterization (in UTCs); more frequently identified microorganisms were E. coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, and Enterococcus faecalis. For these 5 more frequent bacteria, antibiotic susceptibility profiles were determined. High resistance to fluoroquinolones, low resistance to cephalosporins, and very low resistance to nitrofurantoin were found. Specific multidrug-resistant organisms (MDROs) accounted for 11.2%, mostly identified in patients with indwelling catheters. Antibiotic prescriptions in UTIs were according to antibiograms.

Conclusions

In UTIs and UTCs, E. coli was the most common microorganism; microorganisms were distinct on different types of voiding methods. Antibiotic susceptibility profiles were determined for the more frequent bacteria. Very low resistance to nitrofurantoin of E. coli and E. faecalis, low resistance to cephalosporins, and high resistance to fluoroquinolones were found. The data now reported can, in selected cases, facilitate empiric antibiotic selection.

Contaminant Organism Growth in Febrile Infants at Low Risk for Invasive Bacterial Infection

In this multicenter, cross-sectional, secondary analysis of 4042 low-risk febrile infants, nearly 10% had a contaminated culture obtained during their evaluation (4.9% of blood cultures, 5.0% of urine cultures, and 1.8% of cerebrospinal fluid cultures). Our findings have important implications for improving sterile technique and reducing unnecessary cultures.

Decreasing review and notification times of genital and urine cultures in a pediatric emergency department: An observational before and after study

OBJECTIVES

The review of positive culture results by clinical pharmacists in pediatric patients discharged from the emergency department (ED) has not been described. This study aimed to compare review and family notification times of genital and urine cultures before and after initiation of review of positive cultures by clinical pharmacists in a pediatric ED.

METHODS

This was a retrospective review of charts for the study period of 1 year before and 1 year after initiation of review of positive cultures by clinical pharmacists. Positive culture timing results as well as types and rates of interventions were obtained from the electronic chart records.

RESULTS

A total of 681 urine and 171 genital cultures were analyzed. The number of genital and urine cultures were similar in the nurse-driven and pharmacist-driven periods. For urine cultures, the cumulative percentage of notifications in the pharmacist-driven period exceeded that in the nurse-driven period until about 24 hours and again between 24 and 48 hours. By 12 hours, 5.4% of families had been notified in the pharmacist-driven period compared with 1.8% in the nurse-driven period (P = 0.011). More positive cultures were reviewed early in the pharmacist-driven period as well, but by 12 hours, the cumulative percentages were similar: 30.4% in the pharmacist-driven period compared with 27.7% in the nurse-driven period (P = 0.431). For genital cultures, the distribution of notification and review times were similar in both periods.

CONCLUSIONS

The review of positive cultures by clinical pharmacists in a pediatric ED can shorten review and notification times compared with nurses, especially in the first 12 hours.

The Impact of Laboratory Automation on the Time to Urine Microbiological Results: A Five-Year Retrospective Study

Total laboratory automation (TLA) is a valuable component of microbiology laboratories and a growing number of publications suggest the potential impact of automation in terms of analysis standardization, streaking quality, and the turnaround time (TAT). The aim of this project was to perform a detailed investigation of the impact of TLA on the workflow of commonly treated specimens such as urine. This is a retrospective observational study comparing two time periods (pre TLA versus post TLA) for urine specimen culture processing. A total of 35,864 urine specimens were plated during the pre-TLA period and 47,283 were plated during the post-TLA period. The median time from streaking to identification decreased from 22.3 h pre TLA to 21.4 h post TLA (p < 0.001), and the median time from streaking to final validation of the report decreased from 24.3 h pre TLA to 23 h post TLA (p < 0.001). Further analysis revealed that the observed differences in TAT were mainly driven by the contaminated and positive samples. Our findings demonstrate that TLA has the potential to decrease turnaround times of samples in a laboratory. Nevertheless, changes in laboratory workflow (such as extended opening hours for plate reading and antibiotic susceptibility testing or decreased incubation times) might further maximize the efficiency of TLA and optimize TATs.

Pierre Hetz R, Yan X, Lou XY, Fernandez R, Aronson PL, Lion KC. Management of race, ethnicity, and language data in the pediatric emergency department

In this secondary analysis of a multicenter investigation, we describe several gaps in the collection and management of pediatric race, ethnicity, and language data. These findings highlight the ongoing need for reliable data management processes as a crucial step toward advancing pediatric health equity.

C-Reactive Protein Monitoring Identifies Urinary Tract Infections in Ambulatory Kidney Transplant Recipients

Background

Urinary tract infections (UTI) are common in kidney transplant recipients (KTR). Although risk factors for UTI are well described, predicting symptomatic UTI with positive urine cultures in the first posttransplant year is challenging.

Objective

Our clinic routinely monitors serum highly sensitive C-reactive protein (CRP) as part of posttransplant care. We sought to define the role of CRP in identifying symptomatic UTI in KTR.

Design

Nested case control study.

Setting

A large adult single-organ kidney transplant center in Toronto, Canada.

Patients

We identified a nested cohort of 78 KTR who experienced a symptomatic UTI with positive urine cultures (cases) and compared them to a cohort of 78 KTR controls matched by time elapsed posttransplant.

Measurements

Patient demographics, urine cultures, CRP, and kidney function during the first posttransplant year.

Methods

We identified a cohort of KTR transplanted between January 1, 2016, and December 31, 2019. A positive urine culture ordered only for clinical indication in the first posttransplant year identified KTR with a UTI defined >10 5 colony forming units/mL. UTI cases were matched 1:1 to non-UTI controls transplanted immediately preceding or succeeding the UTI case. Bivariate comparisons were performed by t test, Wilcoxon 2-sample test for continuous variables, chi-square, or Fisher's exact test as appropriate, with clinically significant variables entered into multivariable logistic regression models to determine associations.

Results

Older age, female sex, and the presence of a stent were each associated with a UTI. Immediately preceding UTI, eGFR (P = .019), serum albumin (P < .0001), and hemoglobin (P = .002) were lower, while serum CRP (P < .0001) and absolute neutrophils (P = .03) were higher in cases than controls. However, in several multivariable models, only absolute CRP (P = .001), change in CRP (P = .005), female sex (P < .0001), and ureteric stent (P = .008) consistently predicted a UTI. Each 5 mg/dL change between the 2 preceding CRP values predicted a 15% increased likelihood of UTI, while each 1 mg/dL in absolute CRP concentration was associated with a 5% risk.

Limitations

Retrospective case-control design, single-center, small sample size. Hospital inpatients and patients with other infections, acute inflammatory conditions, or rejection were excluded. Urine infections may more easily be detected when patients visit the clinic frequently.

Conclusions

Routine ambulatory CRP monitoring in the first year may help identify subsequent symptomatic UTI in KTR, allow for the initiation of earlier therapy, and reduce patient morbidity.

What was known before?

UTI in KTR are common in the first posttransplant year. Antibiotic therapy is typically not initiated until the results of urine cultures become known.

What this adds

The routine use of appropriate biomarkers such as CRP as part of a posttransplant monitoring strategy may allow clinicians to order urine cultures, help identify UTI earlier, and start therapy sooner, promoting patient well-being.