Microbiology and Virology Department, Azienda Ospedaliera S. Maria degli Angeli, Via Montereale 24, 33170 Pordenone, Italy.
Clin Chim Acta. 2010 Aug 5;411(15-16):1137-42. doi: 10.1016/j.cca.2010.03.027. Epub 2010 Mar 30.
Urine culture is one of the most frequently requested tests in microbiology, and it represents the gold standard for the diagnosis of UTIs. Considering the high prevalence of negative results and the long TAT of the culture test, the use of a rapid and reliable screening method is becoming more and more important, as it reduces the workload, the TAT of negative results, and above all, unnecessary antibiotic prescription.
The Sysmex UF1000i is a new urine flow cytometry analyzer capable of quantifying urinary particles, including BACT, WBCs, and YLCs. To evaluate the analytical performance of the UF1000i as a method for ruling out UTIs, we examined 1349 urine samples and compared the UF1000i results with standard urine culture results.
With instrument cut-off values of 170BACTx10(6)/L and 150WBCsx10(6)/L, we obtained a sensitivity of 98.8%, a specificity of 76.5%, a NPV of 99.5%, and four false negative results (1.2%), avoiding the culture of 57.1% of samples.
The Sysmex UF1000i was capable of improving the efficiency of a routine microbiology laboratory by processing 100samples/h and providing negative results in a few minutes, thus reducing unnecessary testing with an acceptable number of false negative results. In addition, the preliminary evaluation of B_FSC and B_FLH parameters from bacteria histograms seems to be useful for the distinction of bacterial strains detected (Gram-negatives versus Gram-positives). In fact when B_FSC was less than 30 ch, it allowed the distinction of Gram-negative bacteria in 97% of the samples.
尿液培养是微生物学中最常要求的检测之一，是诊断尿路感染的金标准。鉴于阴性结果的高发生率和培养试验的长周转时间，使用快速可靠的筛选方法变得越来越重要，因为它可以减少工作量、阴性结果的周转时间，最重要的是，减少不必要的抗生素处方。
Sysmex UF1000i 是一种新型尿液流式细胞仪分析仪，能够定量尿液中的颗粒，包括 BACT、WBC 和 YLC。为了评估 UF1000i 作为排除尿路感染方法的分析性能，我们检查了 1349 个尿液样本，并将 UF1000i 的结果与标准尿液培养结果进行了比较。
使用仪器截止值 170BACTx10(6)/L 和 150WBCsx10(6)/L，我们获得了 98.8%的敏感性、76.5%的特异性、99.5%的阴性预测值和四个假阴性结果（1.2%），避免了 57.1%的样本培养。
Sysmex UF1000i 能够通过处理 100 个样本/小时和在几分钟内提供阴性结果来提高常规微生物学实验室的效率，从而减少不必要的检测，并具有可接受数量的假阴性结果。此外，细菌直方图中 B_FSC 和 B_FLH 参数的初步评估似乎有助于区分检测到的细菌菌株（革兰氏阴性菌与革兰氏阳性菌）。事实上，当 B_FSC 小于 30ch 时，它可以在 97%的样本中区分革兰氏阴性菌。
