Using the Sysmex UF-4000 urine flow cytometer for rapid diagnosis of urinary tract infection in the clinical microbiological laboratory.

BACKGROUND: Urinary tract infections are responsible for a significant worldwide disease burden. Performing urine culture is time consuming and labor intensive. Urine flow cytometry might provide a quick and reliable method to screen for urinary tract infection. METHODS: We analyzed routinely collected urine samples received between 2020 and 2022 from both inpatients and outpatients. The UF-4000 urine flow cytometer was implemented with an optimal threshold for positivity of ≥100 bacteria/µL. We thereafter validated the prognostic value to detect the presence of urinary tract infection (UTI) based on bacterial (BACT), leukocyte (WBC), and yeast-like cell (YLC) counts combined with the bacterial morphology (UF gram-flag). RESULTS: In the first phase, in 2019, the UF-4000 was implemented using 970 urine samples. In the second phase, between 2020 and 2022, the validation was performed in 42,958 midstream urine samples. The UF-4000 screen resulted in a 37% (n = 15,895) decrease in performed urine cultures. Uropathogens were identified in 18,673 (69%) positively flagged urine samples. BACT > 10.000/µL combined with a gram-negative flag had a >90% positive predictive value for the presence of gram-negative uropathogens. The absence of gram-positive flag or YLC had high negative predictive values (99% and >99%, respectively) and are, therefore, best used to rule out the presence of gram-positive bacteria or yeast. WBC counts did not add to the prediction of uropathogens. CONCLUSION: Implementation of the UF-4000 in routine practice decreased the number of cultured urine samples by 37%. Bacterial cell counts were highly predictive for the presence of UTI, especially when combined with the presence of a gram-negative flag.

The performance of a Fully Automated Urine Particle Analyzer, Sysmex UF-5000, in detecting fastidious bacteria in urine samples.

Several types of fastidious bacteria can cause tract infections. We evaluated the performance of counting fastidious bacteria using a Fully Automated Urine Particle Analyzer UF-5000. The results showed that UF-5000 counts fastidious bacteria in urine without the need for culture using measurement principles based on flow cytometry.

Comparative analysis of different loop types for urine culture collection: Implications for quantitative bacterial growth and culture results.

We hypothesized that the loop material and size could affect the results of the culture when compared to the calibrated pipette. A total of 484 urine samples were included in the study, and each sample was plated by using different loop types and the calibrated pipette. The bacterial counts per milliliter were calculated and compared, with a focus on the important cutoff values of 10³ and 104 CFU/ml for further identification. When considering the 10³ CFU/ml as cutoff value, 1 µl and 10 µl plastic loops gave the highest sensitivity (86.8 %), whereas the 10 µl metal loop had the lowest sensitivity (64.2 %). For the 104 CFU/ml cutoff value, 1 µl plastic loop inoculation demonstrated the highest sensitivity (75.9 %), while the 10 µl metal loop provided the lowest sensitivity (26.5 %). These results suggest that the single use plastic loops are functional, sensitive, useful especially for critical sample.

Preparing for laboratory automation and consolidation-Establishing the validity of pediatric-like low-volume urine samples in boric-acid containing tubes.

Microbiological services consolidation has increased the usage of preservative-containing urine tubes, potentially inhibiting pathogens in low-volume pediatric urine samples, yielding false-negative results. Our study demonstrates comparable growth with 1 ml versus the recommended 3 ml urine, following different shipping intervals. We advocate for regulators to consider similar large-scale validations, ensuring results' consistency.

[Evaluation of Sysmex UF-5000 flow cytometer flag BACT-info for Gram discrimination in urinary tract infection]. / Evaluación del parámetro BACT-info del citómetro de flujo UF-5000 (Sysmex) para la clasificación gram en infección del tracto urinario.

OBJECTIVE: Urine culture as a gold standard for the diagnosis of urinary tract infection (UTI) involves a considerable workload in Clinical Microbiology Departments, due to the high number of samples received that will ultimately be negative. Therefore, it is necessary to use screening systems that also reduce the turnaround time for UTI diagnosis. The new flow cytometer UF-5000 (Sysmex Corporation) is able to differentiate between Gram-negative and Gram-positive bacteria using the BACT-info parameter according to manufacturer. The aim of our study was to evaluate the gram discrimination ability of the UF-5000 cytometer. METHODS: A prospective study with 449 urine samples collected consecutively was conducted, in the period 7/3/2022-27/5/2022, in which the BACT-info flag was compared with urine culture as the reference method. RESULTS: The sensitivity obtained for both Gram-negative and Gram-positive bacteria was above 95%. However, for Gram-positive bacteria, the moderate Kappa index (0.49) and the low positive predictive value (37.1%) indicated that the correlation between BACT-info flag and urine culture was not acceptable and should not be reported to the requesting clinician. CONCLUSIONS: Implementation of the third generation UF-5000 cytometer represents a significant advance in the aetiological orientation of UTIs caused by Gram-negative bacteria. Reporting the Gram morphology in the urine samples reduces the response time in the microbiological diagnosis of UTI, which would have an impact on the reduction and optimisation of empirical treatment, and thus on the generation of antimicrobial resistance.

Analysis of factors with low positive predictive value in the diagnosis of urinary tract infection by flow cytometry.

PURPOSE: Culture-negative urine specimens can be rapidly screened by urine flow cytometry (UFC), while low positive predictive value (PPV) limits the clinical application. We explored the factors associated with a low PPV. METHODS: A total of 5095 urine specimens were analyzed with UFC and culture. Diagnostic performance of leukocytes, bacteria, and BACT-info flags was evaluated by sensitivity, specificity, PPV, and negative predictive value (NPV). The association of contaminated culture and squamous epithelial cell count and BACT-info flag was performed by logistic regression analysis. RESULTS: The NPVs of parallel combination of bacteria and leucocytes were 98.9% in males and 97.9% in females, and PPVs of serial combination were 86.6% and 77.8% in men and women, respectively. The PPV of Gram-negative flag was higher than that of Gram-positive flag. The proportions of contamination in the urine culture results of false positive specimens were 86.9% in males and 98.5% in females at the cutoff points of the serial combination, and these parameters were 53.2% in males and 85.6% in females for the Gram-positive flag. There was a statistically significant association between contaminated cultures and squamous epithelial cells count in females, but not in males. Associations between contaminated cultures and Gram-positive flags or Gram-pos/-neg flags were statistically significant, but there was no association between contaminated cultures and Gram-negative flags. CONCLUSIONS: A serial combination of leukocytes and bacteria may maximize PPV in the diagnosis of bacterial urinary tract infection by urine flow cytometry, and contamination is the main reason for a low PPV.

Usefulness of UF-5000 automatic screening system in UTI diagnosis.

We have evaluated the Sysmex UF-5000 cytometer use in microbiology for the screening of negative urines, looking for cut-off points to detect bacteria and leukocytes. The number of processed urines was 3569, the highest to date in these studies. The best general cut-off point has been 100 bact/µl, giving an area under the ROC curve of 0.868, a sensitivity of 96%, a specificity of 50%, 1.17% of false negatives, and saving 40% of cultures. The PPV and NPV have been 35.5 and 95.4 respectively. The leukocyte count has not been useful. Finally, we have evaluated urine screening usefulness, concluding that in laboratories such as ours (284 urines/working day) or smaller, it is not cost-effective.

Evaluation of automated microscopy sediment analysis in urinary tract infection screening: a practical insight in adjusting fixed cut-off values for urine culture.

PURPOSE: The aim of our study was to evaluate a procedure in which urine culture was only being performed based on fixed cut-off values of urine sediment analysis with intention to prevent unnecessary negative urine cultures. METHODS: From January 2018 to August 2018, all urine samples from patients visiting the urology outpatient department were analyzed. Urine culture was only performed if urine sediment contained more than 130 bacteria per microliter and/or more than 50 leukocytes per microliter. RESULTS: In total, 2821 urine cultures with accompanying urine sediments were analyzed. 2098 cultures (74.4%) were defined negative and 723 (25.6%) positive. By adjusting cut-off values of sediment analysis > 20 per microliter or bacteria more than 330 per microliter, 1051 cultures would have been saved with an estimated cost reduction of € 31.470. Eleven clinically relevant urine cultures would have been missed (1%). CONCLUSION: Using cut-offs values leads to a notable decrease of the total number of urine cultures. According to our analysis, adjusting cut-off values could result in 37% less urine cultures and almost 50% less negative cultures. Hereby, unnecessary cost can be prevented [in our department estimated €31.470 in eight months (€ 47.205/year)].

Evaluation of the Sysmex UF-4000i urine analyzer as a screening test to rule out urinary tract infection and reduce urine cultures. / Évaluation de l'analyseur Sysmex UF-4000i comme test de dépistage pour exclusion des infections urinaires et diminution des mises en culture

INTRODUCTION: Urinary tract infection (UTI) diagnosis by urine culture is time- and labor- consuming. In the Ibn Rochd microbiology laboratory, up to 70% of urine culture samples yield no growth or insignificant growth. OBJECTIVE: To evaluate the new generation of Sysmex UF-4000i fluorescence flow cytometry analyzer with a blue semiconducting laser as a method to rule out negative urine samples for UTI, in comparison of urine culture. MATERIAL AND METHODS: Flow cytometry and microbiological analysis were performed on 502 urine samples included in the study. We used ROC analysis to determine cutoff points at which optimal sensitivity and specificity are achieved for clinical use. RESULTS: Our results showed that bacteria count at a cut-off of 100/µL, and/or the leucocytes count ≥ 45/µL are the optimal indicator for positive culture results. At these cut off, bacteria sensitivity (SE), specificity (SP), Positive predictive value (PPV) and negative predictive value (NPV) were 97,3%, 95%, 87,8% and 98,8% respectively. For leucocytes, SE, SP, PPV and NPV were 99,1%, 95,8%, 88,6% and 99,7% respectively. DISCUSSION AND CONCLUSION: The bacterial and leucocytes counts generated by UF-4000i analysis may be useful in our context as a rapid screening to exclude UTI by reducing about 70% of urines cultures and then workload. Nevertheless, further validation is needed for different patient groups especially with urological disease or immunocompromised patients.

Development, Evaluation, and Multisite Deployment of a Machine Learning Decision Tree Algorithm To Optimize Urinalysis Parameters for Predicting Urine Culture Positivity.

PittUDT, a recursive partitioning decision tree algorithm for predicting urine culture (UC) positivity based on macroscopic and microscopic urinalysis (UA) parameters, was developed in support of a broader system-wide diagnostic stewardship initiative to increase appropriateness of UC testing. Reflex algorithm training utilized results from 19,511 paired UA and UC cases (26.8% UC positive); the average patient age was 57.4 years, and 70% of samples were from female patients. Receiver operating characteristic (ROC) analysis identified urine white blood cells (WBCs), leukocyte esterase, and bacteria as the best predictors of UC positivity, with areas under the ROC curve of 0.79, 0.78, and 0.77, respectively. Using the held-out test data set (9,773 cases; 26.3% UC positive), the PittUDT algorithm met the prespecified target of a negative predictive value above 90% and resulted in a 30 to 60% total negative proportion (true-negative plus false-negative predictions). These data show that a supervised rule-based machine learning algorithm trained on paired UA and UC data has adequate predictive ability for triaging urine specimens by identifying low-risk urine specimens, which are unlikely to grow pathogenic organisms, with a false-negative proportion under 5%. The decision tree approach also generates human-readable rules that can be easily implemented across multiple hospital sites and settings. Our work demonstrates how a data-driven approach can be used to optimize UA parameters for predicting UC positivity in a reflex protocol, with the intent of improving antimicrobial stewardship and UC utilization, a potential avenue for cost savings.

Evolution of Antibiotic Resistance in Escherichia coli and Klebsiella pneumoniae from Urine Cultures

Objective: Determine the evolution of antibiotic resistance of symptomatic bacteriuria caused by Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) in Granada. Material and Method: A descriptive retrospective study was carried out, including antibiograms of urine cultures in which microorganisms identified as E. coli and K. pneumoniae, were isolated in the Microbiology laboratory of the Hospital Universitario Virgen de las Nieves (Granada, Spain) between January 2016 and June 2021. Results: E. coli was the most frequent isolate (10,048) and its resistance to ampicillin (59.45%) and ticarcillin (59.59%), and the increase to cefepime (15.07%) and amoxicillin-clavulanic acid (17.67%) is noteworthy. K. pneumoniae (2222) is notable for resistance to Fosfomycin (27.91%) and an increase to ciprofloxacin (37.79%) and amoxicillin-clavulanic acid (36.63%). Resistance is generally higher in hospitalized patients, males, and adults. Conclusions: Antibiotic resistance to the studied Enterobacteriaceae is on the rise, requiring empirical treatment targeted to the population area (AU)

Is it meaningful to apply midstream urine culture to urine specimens with negative Gram stain results?

INTRODUCTION: Gram staining is a convenient method for bacterial estimation. Urine culture is typically used to diagnose urinary tract infections. Therefore, urine culture is also performed on Gram stain-negative urine specimens. However, the frequency of uropathogen identification in these samples remains unclear. METHODS: From 2016 to 2019, we retrospectively compared the results of Gram staining and urine culture tests on midstream urine specimens submitted for the diagnosis of urinary tract infections to confirm the significance of urine culture on Gram stain-negative specimens. Analysis was performed according to the patients' sex and age, and the frequency of uropathogen identification in the culture was examined. RESULTS: A total of 1763 urine specimens (women, 931; men, 832) were collected. Of these, 448 (25.4%) were not positive on Gram staining but were positive on culture. In specimens without bacteria on Gram staining, the frequencies of specimens with uropathogens detected on culture were 20.8% (22/106) in women aged <50 years, 21.4% (71/332) in women aged ≥50 years, 2.0% (2/99) in men aged <50 years, and 7.8% (39/499) in men aged ≥50 years. CONCLUSIONS: In men aged <50 years, the frequency of uropathogenic bacteria identification by urine culture was low in Gram stain-negative specimens. Therefore, urine cultures may be excluded from this group. In contrast, in women, a small number of Gram stain-negative specimens showed significant culture results for the diagnosis of urinary tract infection. Therefore, urine culture should not be omitted in women without careful consideration.

Accuracy of the Sysmex UF-5000 analyzer for urinary tract infection screening and pathogen classification.

The screening performance of urine flow cytometry parameters (e.g., white blood cell and bacteria) for urinary tract infection (UTI) has been widely recognized. The majority of previous studies, however, investigated the screening performance of Sysmex UF-1000i urine flow cytometer. This study aimed to investigate the screening performance of Sysmex UF-5000 analyzer, a third-generation urinary flow cytometer, for UTI and its novel parameter named Gram flag for discriminating gram-positive and negative pathogens. Urine specimens sent to the clinical microbiology laboratory of our hospital for bacterial culture between September 13, 2021, and November 15, 2021, were prospectively and consecutively collected. The Sysmex UF-5000 analyzer was used to determine urine white blood cell (WBC) and bacteria simultaneously. A chemical strip was used to assess urine nitrate. UTI was defined as positive urine bacterial culture > 104 CFU /ml. The receiver operating characteristics (ROC) curve, nomogram, decision tree, and decision curve were used to determine the screening performance of urine WBC, nitrate, and bacterial. A total of 246 UTIs and 425 non-UTIs were enrolled. The areas under the ROC curve (AUCs) for WBC and bacterial were 0.74 and 0.86, respectively. The decision curve showed that urine bacteria had a higher benefit than WBC. The nomogram indicated that urine bacterial had the largest effect on the probability of UTI. The sensitivity and specificity of the decision tree were 0.69 and 0.95, respectively. The flag of Gram-negative had a positive predictive value (PPV) of 0.93 in patients with urine bacteria > 1367 /µl. Therefore, we conclude that urine bacteria determined by the Sysmex UF-5000 had higher screening performance and greater benefit than WBC. The decision tree can be used to improve the screening performance of routine urinary parameters. The flag of Gram-negative is a reliable indicator to confirm gram-negative bacteria infection in UTI patients.

Prediction of presence of fastidious bacteria by the Fully Automated Urine Particle Analyzer UF-1000i in the case of ineffective antimicrobial therapy for urinary tract infection.

INTRODUCTION: Recent studies have reported associations between fastidious bacteria that are difficult to grow and isolate in conventional urine culture conditions and urinary tract infections (UTIs). Because the Fully Automated Urine Particle Analyzer UF-1000i (hereinafter referred to as "UF-1000i") detects fastidious bacteria without being affected by culture conditions, owing to its flow cytometry-based principle, we evaluated the robustness of UF-1000i detection using clinical urine samples from patients with UTIs following ineffective antimicrobial therapy. METHODS: A total of 150 patients diagnosed with UTIs were enrolled, and their laboratory findings were analyzed, focusing on the discrepancy in bacterial numbers between UF-1000i and conventional culture at each antimicrobial therapy effectiveness classification. In addition, gene identification was conducted by molecular analysis using 16S ribosomal RNA gene sequencing and next-generation sequencing (NGS) to elucidate the reason for the presence of fastidious bacteria in these samples. RESULTS: The ineffective therapy cases showed more than 100-fold discrepancy in bacterial counts, with a higher proportion (30.8%) than effective therapy cases without secondary administration (5.7%) between the bacterial counts in UF-1000i and conventional culture methods. The presence rates of fastidious bacteria were 100% and 66.7% in discrepant cases of ineffective and effective without secondary administrations, respectively. CONCLUSION: This study suggests that discrepancies in bacterial numbers between the conventional culture method and UF-1000i measurement at the primary visit can predict the presence of fastidious bacteria, especially in cases of ineffective antimicrobial therapy.

Lens Free Holographic Imaging for Urinary Tract Infection Screening.

OBJECTIVE: The diagnosis of urinary tract infection (UTI) currently requires precise specimen collection, handling infectious human waste, controlled urine storage, and timely transportation to modern laboratory equipment for analysis. Here we investigate holographic lens free imaging (LFI) to show its promise for enabling automatic urine analysis at the patient bedside. METHODS: We introduce an LFI system capable of resolving important urine clinical biomarkers such as red blood cells, white blood cells, crystals, and casts in 2 mm thick urine phantoms. RESULTS: This approach is sensitive to the particulate concentrations relevant for detecting several clinical urine abnormalities such as hematuria and pyuria, linearly correlating to ground truth hemacytometer measurements with R 2 = 0.9941 and R 2 = 0.9973, respectively. We show that LFI can estimate E. coli concentrations of 10 3 to 10 5 cells/mL by counting individual cells, and is sensitive to concentrations of 10 5 cells/mL to 10 8 cells/mL by analyzing hologram texture. Further, LFI measurements of blood cell concentrations are relatively insensitive to changes in bacteria concentrations of over seven orders of magnitude. Lastly, LFI reveals clear differences between UTI-positive and UTI-negative urine from human patients. CONCLUSION: LFI is sensitive to clinically-relevant concentrations of bacteria, blood cells, and other sediment in large urine volumes. SIGNIFICANCE: Together, these results show promise for LFI as a tool for urine screening, potentially offering early, point-of-care detection of UTI and other pathological processes.

Performance of Sysmex UF-5000 for candiduria screening.

In this study, we tested the performance of the Sysmex UF-5000 system to detect yeast-like cell (YLC) counting to screen for candiduria. Urine samples were screened for leukocyte and yeast amount by flow cytometry and results were compared with fungal culture results. A total of 56,749 urine samples were enrolled in this study. Urine culture and urinalysis of YLC data were used to evaluate the performance of YLC in diagnosing candiduria. Different cut-off values (YLC. 5, 10, 20, 50, 100/µl) were evaluated. Youden index was used to determine the ideal cut-off value, and the highest was 0.95 with 5 YLC/µl. When the cut-off value for YLC is 5 cells/µl, 95.15% of the samples were "negative" with flow cytometry and culture (NPV:100%). In conclusion, detection of YLC by flow cytometer (Sysmex UF-5000) can be a rapid alternative method to exclude candiduria prior to urine culture.

Tira reactiva en orina para el diagnóstico de bacteriuria asintomática en gestantes / Orine reactive strip for diagnosing asymptomatic bacteriuria in pregnant women

INTRODUCCIÓN: Este documento técnico se realiza a solicitud de la Dirección de Salud Sexual y Reproductiva (DSARE) a través de la Dirección General de Intervenciones Estratégicas en Salud Pública. a. Cuadro clínico: Las infecciones urinarias son más frecuentes en las mujeres que en los hombres y esta tendencia se acentúa durante el embarazo debido a cambios fisiológicos. El 2 a 15% de las gestantes, se ve afectada por la bacteriuria asintomática, siendo un problema de salud pública, en algunos lugares en los que este índice es mayor. Se ha demostrado que la bacteriuria no tratada durante el embarazo se asocia con muchas complicaciones, siendo la complicación más frecuente el parto prematuro que se presenta en 5 al 10% de todos los embarazos, siendo causa de morbilidad y mortalidad perinatal, estando relacionado al 75% de las muertes perinatales y al 50% de las secuelas neurológicas. Otras complicaciones son bajo peso al nacer y pielonefritis, esta última condición se presenta con un riesgo de 20 a 30 veces más en las mujeres que tienen bacteriuria, que en las que no tienen la infección(1). Las infecciones del tracto urinario se diagnostican generalmente, mediante muestras de orina y pruebas con tiras reactivas o urocultivos (gold estándar). b. Tecnología sanitária: Una tira reactiva es un instrumento de diagnóstico simple utilizado para realizar un rápido examen físico-químico de orina con el objetivo de detectar algunos cambios patológicos. Consiste en una tira de material plástico o papel, con unas almohadillas impregnadas de reactivos químicos que reaccionan con las sustancias presentes en la orina, produciendo cambios cromáticos característicos, en relación a varias determinaciones simultáneas. Valores altos de leucocitos en la orina, son indicativos de infección urinaria, y son detectados por la tira reactiva a través de la detección de la enzima esterasa leucocitaria. Si bien el aumento de leucocitos está relacionado a infecciones urinarias; las nefritis intersticiales, tóxicas, las infecciones causadas por Trichomonas vaginalis, Chlamydia trachomatis y levaduras producen leucocituria, sin bacteriuria. La tira reactiva detecta la formación de nitritos, por la acción de bacterias reductoras de nitrato, que comúnmente causan infecciones urinarias. Las bacterias gram positivas, también causantes de infecciones urinarias, no son detectadas por este método. El urocultivo estándar se realiza mediante la inoculación de orina, con un asa calibrada, en una placa de agar-sangre (medio de crecimiento) y agar MacConkey (medio selectivo que facilita el desarrollo de la mayoría de las enterobacterias) y sembrando en estrías toda la superficie de la placa para obtener recuentos cuantitativos de colonias. Se incuban las placas aeróbicamente a 35 °C durante 18-20 horas. Cada bacteria viva, da lugar a una colonia, transcurrido el periodo de incubación se cuenta cada colonia de diferente morfología, informando el número de unidades formadoras de colonias por ml de orina (UFC/ml), multiplicando el factor de la alícuota tomada por el número de colonias contadas en la placa. De no observarse crecimiento, el cultivo se informa como "sin crecimiento". En muchos laboratorios se utiliza el medio de CLED (Cistina Lactosa Electrolito Deficiente) como único medio de cultivo, en sustitución del agar-sangre y agar MacConkey (2). El urocultivo, además de permitir identificar los organismos causales de la infección, permite determinar la sensibilidad a los antibióticos. OBJETIVO: Describir la evidencia científica disponible sobre la precisión diagnóstica de la tira reactiva de aplicación en orina, para el diagnóstico de bacteriuria asintomática en gestantes. METODOLOGÍA: Se realizó una búsqueda sistemática en Medline vía Pubmed, Cochrane y LILACS, complementada con la búsqueda en buscadores genéricos (Google Scholar) y literatura gris. Se prioriza guías de práctica clínica (GPC), revisiones sistemáticas (RS) con o sin metanálisis (MA) de ECA, ensayos clínicos aleatorizados controlados (ECA), evaluaciones de tecnología sanitaria (ETS) y evaluaciones económicas (EE) de América Latina. La calidad de la evidencia se valoró usando AMSTAR 2 para RS, la herramienta de evaluación de riesgo de sesgo de la colaboración Cochrane para ECA y AGREE II para las GPC. RESULTADOS: Se seleccionó cinco guías de práctica clínica (3­7) y una revisión sistemática con metanálisis(8) . No se identificaron evaluaciones de tecnología sanitaria ni evaluaciones económicas de la región. En el 2016, Rogozinska E et al., realizaron una revisión sistemática con metanálisis (8), cuyo objetivo fue determinar la exactitud de las pruebas rápidas de bajo costo en el punto de atención, para detectar bacteriuria asintomática en gestantes. Fueron nueve las pruebas evaluadas en 27 estudios (Tabla 11): 1) tiras reactivas con marcador para nitrito, 2) tiras reactivas con marcador para nitrito o leucocitos, 3) análisis de orina con contaje de bacterias (urianálisis), 4) dipslide (Uricult), 5) dipslide con tinción Gram en orina no centrifugada, 6) dipslide (Microstix-3), 7) prueba Griess para detectar nitritos, 8) prueba para reacción de clorhexidina y 9) test de catalasa. CONCLUSIONES: La Organización Mundial de la Salud (OMS) considera que el cultivo de muestras de orina es el método recomendado para diagnosticar la bacteriuria asintomática en gestantes; y en entornos donde no es posible realizar urocultivos, se recomienda realizar in situ la tinción de Gram a muestras de orina antes que usar tiras reactivas. La Revisión Sistemática (RS) seleccionada tuvo un nivel de confianza alta. Las GPC incluidas obtuvieron un puntaje en la valoración global de calidad mayor al 90%. Las pruebas rápidas analizadas en la RS mostraron los siguientes resultados de sensibilidad y especificidad: La sensibilidad agrupada de los dipstick para detección de nitritos positivos fue 55% (IC 95%: 42%- 67%) y la especificidad del 99% (IC 95%: 98% - 99%). La sensibilidad agrupada de los dipstick para la detección de leucocitos o nitritos positivos fue 73% (IC 95% :59% ­ 83%) y una especificidad del 89% (IC95%: 79%­ 94%); La reacción de clorhexidina y test de catalasa (Uriscreen test) contribuyeron a una sensibilidad del 100% (IC95%, 65%­100%) y una especificidad de 54% (IC95%: 46%­62%); el Test de Griess (nitritos) al ser comparado con la prueba de catalasa tuvo una sensibilidad del 65% (IC 95% 50%­78%) con una especificidad del 99% (IC 95% 98%­100%); el urinálisis (conteo de más de 20 bacterias/campo de alto poder [High Power Field (de sus siglas en inglés HPF)] tuvo una sensibilidad del 78% (IC 95%: 45%­94%) y una especificidad del 92% (IC 95%: 88%­94%); Dipslide (Uricult) tuvo una sensibilidad del 92% (IC95%: 69%­100%) y especificidad del 85% (IC95%: 24%­100%); y dipslide con tinción Gram en orina no centrifugada tuvo una sensibilidad de 86% (IC 95% 80%­91%) y una especificidad del 97% (IC95% 93%­ 99%); y el Dipslide (Microstix-3) tuvo una sensibilidad del 67% (IC95%: 38%- 88%) y una especificidad del 93% (IC95%: 89%-95%). El cultivo de orina es el "gold standard" para detectar bacteriuria asintomática. Esta prueba tiene una sensibilidad alta del 94%; siendo su especificidad 89% y su VPP 93%. Por ello, sigue siendo la prueba recomendada para detección de bacteriuria en gestantes; según lo reportado por los estudios incluidos en esta revisión, la tira reactiva presenta una sensibilidad baja, para detectar la bacteriuria asintomática. En los EESS donde existe escasez de recursos y personal entrenado debe accederse a otras pruebas como la prueba dipslide que ha demostrado ser útil, debido a que es muy probable que una gestante con una prueba dipslide positiva tenga un diagnóstico definitivo de bacteriuria asintomática, mientras que un resultado negativo descarta efectivamente la presencia de bacteriuria.

A Child's urine is not sterile: A pilot study evaluating the Pediatric Urinary Microbiome.

INTRODUCTION: A bladder microbiome (urobiome) exists in adults. Data supports the effects of the adult urobiome on urinary tract health with associations between dysbiotic urobiomes and lower urinary tract disorders. Understanding urobiome origin is important since other microbiomes establish around birth and microbiome alterations are linked to disease development. However, the pediatric urobiome has not been well studied. OBJECTIVES: We sought to determine the age when the urobiome develops, compare the pediatric urobiome to microbiomes of adjacent urogenital niches, and compare the urobiomes between boys and girls and across age groups. STUDY DESIGN: Seventy-four children less than 18 years of age without recent antibiotic exposure were recruited, including 48 males and 26 females, aged 2 weeks to 209 months of age. Transurethral catheterized urine samples and samples from the perineum, urethra, vagina, and foreskin were collected. Specimens were assessed using the expanded quantitative urine culture protocol and by 16S rRNA gene sequencing. Dada2 was used to profile microbial compositions, and BLCA was used to identify microbial taxa. RESULTS: Bacteria were detected in 90.5% of urine samples and identified in children as young as 2 weeks of age. Microbial communities and compositions of the female bladder and other urogenital niches (urethra, perineum, and vagina) differed significantly by age. Lactobacillus predominated the bladder, urethral, and vaginal microbiomes in post-pubertal girls. Compared to female urinary microbiomes, those of males differed less substantially. Only perineal microbiomes differed significantly by age, whereas male urethral and foreskin microbiomes did not differ significantly. DISCUSSION: We identified that a urinary microbiome is established as early as infancy. In addition, the female urobiome changes throughout childhood, until the post-pubertal bacterial taxa becomes consistent with that seen in adult females. Whereas in boys, the urinary microbiome changed very little over time. In addition, the surrounding urogenital microbiomes differed less in boys as compared to females. Microbiomes established at a young age may have long-term influences on immune, metabolic, and neurobehavioral traits. The same may be true for the urobiome. Our study provides a foundation for future research to determine the influence of the pediatric urobiome on the development of urinary and even non-urinary disorders. CONCLUSIONS: A pediatric urobiome exists, with differences between males and females and can be detected at a young age with changes occurring throughout childhood. Similarities and differences are also seen between the pediatric urobiome and adjacent niches.