Evaluación de un sistema automatizado de siembra de orinas para urocultivos / Evaluation of an automated streaking system of urine samples for urine cultures

Introduction: Automated systems have simplified laboratory workflow, improved standardization, traceability and diminished human errors and workload. Although microbiology laboratories have little automation, in recent years new tools for automating pre analytical steps have appeared. Objectives: To assess the performance of an automated streaking machine for urine cultures and its agreement with the conventional manual plating method for semi quantitative colony counts. Materials and Methods: 495 urine samples for urinary culture were inoculated in CPS® agar using our standard protocol and the PREVI™ Isola. Rates of positivity, negativity, polymicrobial growth, bacterial species, colony counts and re-isolation requirements were compared. Results: Agreement was achieved in 98.97% of the positive/negative results, in 99.39% of the polymicrobial growth, 99.76% of bacterial species isolated and in 98.56 % of colony counts. The need for re-isolation of colonies decreased from 12.1% to 1.1% using the automated system. Discussion: PREVI™ Isola's performance was as expected, time saving and improving bacterial isolation. It represents a helpful tool for laboratory automation.

Introducción: Los sistemas automatizados han facilitado el flujo de trabajo, mejorado la estandarización, la trazabilidad, disminuido el error humano y la carga de trabajo en los laboratorios. A pesar de que la microbiología ha permanecido poco automatizada, en los últimos años han aparecido nuevas herramientas para la automatización de la etapa pre analítica. Objetivos: Evaluar el desempeño de un sistema automatizado de siembra de urocultivos y la concordancia con la siembra manual convencional en el recuento semicuantitativo de colonias. Materiales y Métodos: 495 muestras de orinas fueron sembradas según nuestro protocolo habitual y comparadas con las placas de CPS® obtenidas con PREVI™ Isola en cuanto a positividad/negatividad, muestras polimicrobianas, especies de bacterias aisladas, recuentos y necesidad de resembrar. Resultados: Hubo concordancia en 98,97% de los positivos y negativos, en 99,39% de las muestras polimicrobianas, en 99,76% de las especies aisladas y en 98,56% de los recuentos. La necesidad de resiembra disminuyo de 12,1% a un 1,1% usando este sistema automatizado. Discusión: El desempeño de PREVI™ Isola fue el esperado, mejorando el aislamiento bacteriano y el tiempo requerido y representa una buena herramienta para la automatización de laboratorios.

Padronização da avaliação da função renal de ratos (Rattus norvegicus) Wistar do biotério da Universidade Federal de Juiz de Fora / Standardization of renal function evaluation in Wistar rats (Rattus norvegicus) from the Federal University of Juiz de Fora's colony

Introdução: Há grande interesse na utilização de modelos animais na pesquisa da fisiopatologia renal, que requer padronização dos parâmetros analisados. Objetivo: Padronizar avaliação da função renal de ratos da colônia do biotério do Centro de Biologia da Reprodução da Universidade Federal de Juiz de Fora. Métodos: Foram utilizados 30 ratos Wistar e realizadas dosagens de creatinina (sérica e urinária), ureia sérica e proteinúria. Foram avaliados: o intervalo de coleta de urina nas gaiolas metabólicas (24 horas ou 12 horas); a necessidade de jejum de 12 horas; a necessidade de desproteinização das amostras de urina e soro para dosagens de creatinina; necessidade de desproteinização do soro de animais com injúria renal aguda (IRA) para leitura em espectrofotômetro e ELISA, além da comparação da proteinúria de 24 horas (PT 24 horas) com a relação proteína/creatinina (rP/C). Os resultados foram comparados pelos teste t de Student, correlação de Pearson, gráfico de Bland-Altman para concordância e modelo de regressão linear para estimar a PT 24 horas a partir da rP/C. Resultados: A diurese de 24 horas foi maior do que a de 12 horas, interferindo na depuração da creatinina. No grupo em jejum, houve menor ingestão hídrica e menor creatinina urinária. Houve grande variabilidade para o soro desproteinizado e as leituras realizadas nos dois equipamentos foram semelhantes. Houve forte correlação entre PT 24 horas e rP/C e foi gerada a equação: PT 24 horas = (8,6113 x rP/C) + 1,0869. Conclusão: Foi padronizada: coleta de urina em 24 horas sem jejum. A desproteinização não mostrou benefício. As dosagens foram realizadas com confiabilidade em espectrofotômetro. Foi ...

Introduction: There is great interest in the use of animal models in the study of renal pathophysiology requires standardization of parameters. Objective: Standardize assessment of renal function in rats from in the Center for Reproductive Biology of Federal University of Juiz de Fora's colony. Methods: Thirty Wistar rats were used and performed measurements of creatinine (serum and urine), serum urea and proteinuria. Were evaluated: the urine collection interval in metabolic cages (24 hours or 12 hours), the need for 12-hour fast, the need of urine and serum deproteinization for creatinine measurement, need of serum deproteinization in animals with acute kidney injury to a spectrophotometer and ELISA, and the comparison of 24-hour proteinuria (PT 24 hours) with the protein/creatinine ratio (rP/C). Means were compared by the Student's t test, Pearson correlation, Bland-Altman plot for agreement and linear regression model to estimate PT 24 hours from rP/C. Results: The 24 hours urine output was greater than 12 hours, interfering with the creatinine clearance calculation. In the fasting group showed less water intake and lower urinary creatinine. There was great variability for the deproteinized whey and readings performed in the two devices were similar. There was a strong correlation between PT 24 hours and rP/C and the equation was generated: PT 24 hours = (8.6113 x rP/C) + 1.0869. Conclusion: Was standardized: 24-hour urine collection without fasting. The deproteinization showed no benefit. The measurements were performed with spectrophotometer reliability. It generated a practical formula for estimating PT 24 hours through rP/C. .

Evaluation of the Performance of a Micromethod for Measuring Urinary Iodine by Using Six Sigma Quality Metrics

BACKGROUND: The urinary iodine micromethod (UIMM) is a modification of the conventional method and its performance needs evaluation. METHODS: UIMM performance was evaluated using the method validation and 2008 Iodine Deficiency Disorders survey data obtained from four urinary iodine (UI) laboratories. Method acceptability tests and Sigma quality metrics were determined using total allowable errors (TEas) set by two external quality assurance (EQA) providers. RESULTS: UIMM obeyed various method acceptability test criteria with some discrepancies at low concentrations. Method validation data calculated against the UI Quality Program (TUIQP) TEas showed that the Sigma metrics were at 2.75, 1.80, and 3.80 for 51+/-15.50 microg/L, 108+/-32.40 microg/L, and 149+/-38.60 microg/L UI, respectively. External quality control (EQC) data showed that the performance of the laboratories was within Sigma metrics of 0.85-1.12, 1.57-4.36, and 1.46-4.98 at 46.91+/-7.05 microg/L, 135.14+/-13.53 microg/L, and 238.58+/-17.90 microg/L, respectively. No laboratory showed a calculated total error (TEcalc)

Cost benefit of the routine urinalysis

In the present health care environment, cost-benefit analysis is extremely important. In this screening program, the minimal cost of screening dipstick urinalysis in 1601 asymptomatic school children was determined. The process of screening was similar to all the studies. The minimal cost utilizing 3 general physicians was calculated. Costs were determined by using current charge for supplies ordered to perform tests, charges for tests performed by a commercial laboratory, and the cost of a final evaluation by a pediatric nephrologist. Initial abnormal urinalysis was found in 4.7% [76/1601] of patients. Upon retesting 1.37% [22/1601] of patients were calculated to have a persistent abnormality. The calculated cost was 1/530/000 Rials [164.5 $] to initially screen all 1601 patients with a dipstick urinalysis or 850 Rials [0.09 $] per patient. The calculated cost to evaluate the 22 patients with any persistent abnormality on repeat dipstick urinalysis was 246/840 Rials [26.5 $] or 11.220 Rials [1.2 $] per patient. This is the calculated cost for a single screening of 1601 asymptomatic pediatric patients. Multiple screening dipstick urinalysis in asymptomatic pediatric are costly and should be discontinued. We purpose that a single screening dipstick urinalysis be obtained at school entry age, between 6 and 7 years old, in all asymptomatic children

El segundo bienio del Programa de Evaluación Externa de Calidad en Uroanálisis (PEECU) / The second biennial of the External Quality Evaluation Program in Urinalysis (PEECU)

OBJECTIVE: To characterize the participation of clinical laboratories in the second biennial of an external quality assurance scheme for urinalysis in Mexico. METHODS: The participants received 32 control samples in 8 shipments of 4 controls each during the biennial 1999-2000. The controls were in the form of tablets to be dissolved in 12 mL of water to mimic urine. The participants performed dipstick assays of pH, specific gravity (SG) and 8 analytes (proteins, glucose, ketones, blood, bilirubin, nitrites, urobilinogen, leukocytes) in the controls. Expected control values were assigned by 10-15 replicate automated assays using dipsticks and apparatus of a single provider (Bayer). Participants' results were transformed to scores ranging from zero (perfect result) to 400 (worst possible). Score differences were analyzed using nonparametric methods (Kruskal-Wallis and Mann-Whitney). RESULTS: The best results were seen for nitrites, ketones and proteins (mean global scores = 3-5) and the worst for SG (score = 45) with intermediate scores of 10-13 for the other six. CONCLUSIONS: The scores improved for the second biennial from a grand mean of 17 in the first significantly down to 12 in the second. The number of participants has been increasing yearly and there has been a decrease of participants who do not report at least 3 out of 4 yearly shipments. We confirmed that automated readings yield better scores than visual readings.

Proposta de um modelo de padronizaçäo para o exame sumário de urina / Proposal to standardization model for the urinalysis

O exame sumário de urina representa sem dúvida um elemento indispensável na detecçäo de diversas doenças do trato urinário, metabólicas ou sistêmicas näo relacionadas com o rim. Quando realizado e interpretado criteriosamente, oferece ao solicitante valiosas informaçöes para o esclarecimento diagnóstico. O presente trabalho tem como objetivo propor um modelo de padronizaçäo de resultados, descritos de acordo com o exame físico (volume, cor, aspecto, depósito e densidade), pesquisas bioquímicas realizadas através de tiras reativas (pH, proteínas, glicose, corpos cetônicos, hemoglobina, urobilinogênio, bilirrubina, esterase leucocitária e nitrito) e os elementos encontrados na sedimentoscopia urinária (células epiteliais de descamaçäo, leucócitos, hemácias, cilindros, bactérias, muco, cristais, sais amorfos, leveduras, espermatozóides e parasitas). Além desses parâmetros, algumas observaçöes podem ser descritas, quando necessárias, com a finalidade de fornecer informaçöes ao clínico que possam auxiliar no diagnóstico de doenças mais específicas. Sabe-se da existência de vários interferentes na urina que podem provocar reaçöes falso-negativas. Por este motivo, a confirmaçäo de alguns componentes urinários (proteínas, glicose, bilirrubina e urobilinogênio) é necessária para garantir a exatidäo do resultado. A padronizaçäo de procedimentos poderá evitar as diferentes formas de transcriçäo do laudo interlaboratorial, o que ocasiona interpretaçäo e tratamento inadequados

Quality control in urinalysis.

Quality control (QC) has been introduced in laboratories, and QC surveys in urinalysis have been performed by College of American Pathologist, by Japanese Association of Medical Technologists, by Osaka Medical Association and by manufacturers. QC survey in urinalysis for synthetic urine by the reagent strip and instrument made in same manufacturer, and by an automated urine cell analyser provided satisfactory results among laboratories. QC survey in urinalysis for synthetic urine by the reagent strips and instruments made by various manufacturers indicated differences in the determination values among manufacturers, and between manual and automated methods because the reagent strips and instruments have different characteristics, respectively. QC photo survey in urinalysis on the microscopic photos of urine sediment constituents indicated differences in the identification of cells among laboratories. From the results, it is necessary to standardize a reagent strip method, manual and automated methods, and synthetic urine.

Screening for asymptomatic bacteriuria in pregnant women: urinalysis versus urine culture.

A diagnostic test study was conducted to evaluate the diagnostic performance of a simple urinalysis as a screening test for asymptomatic bacteriuria (ABU) in pregnant women. Seven hundred and seventy four asymptomatic pregnant women attending their first antenatal care at Srinagarind Hospital from June 1, 1994 to January 31, 1995 were studied. Simple urinalysis and urine culture were performed on all 774 subjects. The presence of > or = 5 WBC/HPF of centrifuged urine indicated a positive test. ABU was defined as the presence of > or = 10(5) colony forming units of single bacteria per milliliter of urine. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of simple urinalysis in detecting ABU, using urine culture as a gold standard were calculated. Simple urinalysis had a 18.4 per cent sensitivity, 97.2 per cent specificity, 45.7 per cent positive predictive value, 90.4 per cent negative predictive value and 88.4 per cent accuracy in detecting ABU. Because of its low sensitivity and the possible consequences of ABU, simple urinalysis should not be used as a screening test for ABU.

Los dos primeros años del programa de evaluación externa de calidad en uroanálisis (PEECU) / The firts two years of an external quality assurance scheme for strip uroanalysis

Objetivo. Analizar los datos de uroanálisis con tira reactiva generados en los primeros dos años de un programa externo de control de calidad. Métodos. Los participantes recibieron 32 controles (4 por 8 envíos) en forma de tabletas para disolver y analizar usando tiras reactivas de uroanálisis. El número de participantes aumentó de < 50 en el 1er. envío a > 200 en el 8o. Midieron de 6 a 10 analitos según el tipo de tira utilizada y enviaron 763 informes. En cada informe se calculó una puntuación por analito (n = 4), por envío (n = 24 a 40) y una global de los 8 envíos (n = 707 a 763), La puntuación de obtuvo comparando el resultado informado con la moda de unos 600 laboratorios de Canadá y EEUU que midieron los mismos 32 controles utilizando exclusivamente tiras Bayer y lecturas instrumentales. La puntuación se extendió de cero ideal a un máximo de 400 puntos malos. Resultados. la mejor puntuación global (3 puntos en 741 informes) fue en nitritos y la peor (58 puntos en 744 informes) en gravedad específica (GE). Los otros ocho analitos tuvieron globales de 11 a 19 puntos (tabla 1). Las puntuaciones más bajas por tipo de métodos (tabla 2) fueron con tiras y aparatos automatizados Bayer (global de 13 puntos) y las lecturas visuales con tiras Bayer (global de 21). Conclusiones. 1. Los resultados nos llevaron a la decisión de suspender el envío de controles a participantes que usan tiras de otras marcas ya que el programa, por estar diseñado por usuarios de tiras Bayer, puede contribuir desorientar a los usuarios de otras tiras. 2. Se confirmó que la lectura instrumental es superior a la visual. 3. Ameritan estudio las causas de la puntuación alta de GE