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BACKGROUND: Recently, a new automated inoculating instrument, Previ Isola(R) (bioMerieux, France) was introduced. Although there are many evaluation reports about the inoculation of urine and body fluid samples using Previ Isola(R), no evaluation has been reported for blood samples. The objectives of this study were to evaluate this instrument for the inoculation of blood samples and to compare the microbiological results with the manual loop-to-plate method. METHODS: From March 2014 to July 2014, a total of 296 non-duplicate blood samples showing positive signals on the BacT/Alert 3D system were obtained, and both manual and automated methods were used for sample inoculation. Results of the two methods were compared according to five aspects: the culture result, number of single colonies, morphology of colonies, number of re-inoculations, and time required for inoculation. RESULTS: The sensitivity and specificity of Previ Isola(R) were 98.9% and 96.6%, respectively. The positive and negative predictive values were 99.6% and 90.3%, respectively, and the total concordance rate was 98.6%. For Previ Isola(R) and the manual methods, the number of average usable single colonies per plate was 25 and 16, the number of re-inoculations was 60 and 62, and the inoculation time for 15 blood samples was 30 min and 75 min, respectively. The morphology of colonies showed no differences between the two methods. CONCLUSIONS: The automated inoculation instrument, Previ Isola(R), showed relative good concordance with manual method, with high sensitivity and high specificity for blood sample inoculation. Previ Isola(R) may be useful for inoculating specimens including blood samples.
Subject(s)
Automation , Body Fluids , Evaluation Studies as Topic , Sensitivity and SpecificityABSTRACT
Objective To evaluate the characteristics of the PREVI Isola automated plate streaker (bioMérieux,SA).Methods 80 respiratory tract specimens,70 sterile fluids,52 stools,69 swabs,12 cerebrospinal fluids and 80 urines were collected in Peking Union Medicd College Hospital.Specimens were processed with manual streaking and PREVI Isola system.PREVI Isola system were evaluated comparing to the manual streaking.The quality of results were analyzed by SPSS 16.0, doing Wilcoxon’s Sign Rank Test for the results of finally isolated species,overall numbers of isolated colonies and semi-quantita-tive of the species were both isolated by the two methods.Results PREVI Isola system was highly automatic,which could select the right plates and stake the bar code on the back of the plate indicating the type of the agar and inoculation time, PREVI Isola system could accurately absorb the liquid specimen and use a novel comb streaking procedure for processing of fluid specimens on standard agar plates,like 17 inoculating loops work together.It also had a good reproducibility.The quali-ty of PREVI Isola system results:As to the finally isolated species,there was significant statistical difference between PREVI Isola system and manual streaking method in respiratory tract and stools specimen,there were more species isolated by manual streaking method than PREVI Isola system.There were no differences between the two methods for the other of specimen types.As to the amount of pure clones of the species were both isolated by the two methods,there were significant statistical differences between the two methods for respiratory tract,sterile fluid and stool specimens.The amount of clones isolated by PREVI Isola system was more than manual streaking method.In semi-quantitative results,there were significant statistical differences between the two methods for respiratory tract and urine specimen,Species had wider distribution of PREVI Isola system than manual streaking method.Inoculation efficiency:if the batch of specimen type was simple (mainly the urine and so on),using the same plates,PREVI Isola system was more efficient than manual streaking method.Howev-er,if the batch of specimen type was complicated,manual method was high-performance.Besides,not all specimen type could be inoculated by PREVI Isola system,such as cerebrospinal fluid,catheter and tissues.Conclusion If the lab had simple specimen type,or utilize the specimen type using the same agar plates to be inoculated together,PREVI Isola system belongs to a good performance automated plate streaker.
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BACKGROUND: This study was designed as a quasi-experiment to evaluate automatic inoculation of fecal specimens, using the automated specimen inoculator Previ Isola (bioMerieux, France). METHODS: We evaluated the quality of cultures, recovery rates of enteropathogenic bacteria (Salmonella, Shigella, Campylobacter, and Yersinia species), and cost-effectiveness in terms of technical time. The Previ Isola recovery rates for the two-year period from August 2009 to July 2011 were compared with historical manual inoculation data of the previous two years (August 2007 to July 2009). The regional (Baden-Wurttemberg) and nationwide (Germany) trends of recovery rates for this four-year period were referred. RESULTS: A total of 5,884 fecal specimens were collected over the study period. Most positive cultures were for Salmonella, followed by Campylobacter. Compared with the historical data, the numbers of Campylobacter-positive specimens for a year between August and July were increased significantly, from 19 in 2007-2008 and 10 in 2008-2009 to 32 in 2009-2010 (P=0.002) and 32 in 2010-2011 (P=0.003), respectively. During the study period, the official data for our region and nationwide did not show this increase in the recovery rate of Campylobacter. For Salmonella, Shigella, and Yersinia, no significant changes were observed. Compared with manual inoculation, the mean hands-on time with Previ Isola inoculation was significantly shortened, from 37:30 min to 8:42 min per 15 fecal specimens. CONCLUSIONS: Inoculation by Previ Isola improves the quality of routine culture of fecal specimens, with better sensitivity for Campylobacter and less hands-on time.
Subject(s)
Humans , Automation , Bacteria/isolation & purification , Bacteriological Techniques/methods , Campylobacter/isolation & purification , Feces/microbiology , Quality Control , Salmonella/isolation & purification , Shigella/isolation & purification , Yersinia/isolation & purificationABSTRACT
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.