Ilki A, Ayas R, Ozsoy S, Soyletir G
Marmara University School of Medicine, Istanbul, Turkey.
Eur J Clin Microbiol Infect Dis. 2017 Jul;36(7):1119-1123. doi: 10.1007/s10096-017-2898-7. Epub 2017 Jan 22.
Urine samples account for a significant part of the workload in clinical microbiology laboratories. However, the culture process is time-consuming and a large proportion is reported as negative. To reduce unnecessary culture procedures and speed up the reporting of negative results, a reliable screening method is needed. For this purpose, urine samples submitted to our clinical microbiology laboratory were simultaneously screened by a flow cytometry method (Sysmex UF-1000i, Japan). During screening, the evaluation of various combinations of leucocytes and bacteria cut-offs demonstrated that cut-offs of 30 and 50/μL, respectively, were the best threshold values to reach a 100% negative predictive value (NPV) with a culture reduction rate of 44.8% in adults and 61.9% in children between the ages of 6 and 17 years. With the culture reduction rates mentioned above, the screening method has provided at least 24% savings in expenditures of the routine clinical microbiology laboratory. Since we did not reach such an NPV with any combinations of screening parameters in children younger than 5 years of age, we recommend cultivation of all urine samples in those patients without a screening step. In conclusion, Sysmex UF-1000i as a screening method was capable of improving the efficiency of the routine microbiology laboratory by providing negative results in a few minutes in children greater than 6 years of age and in adults.
尿液样本在临床微生物实验室的工作量中占很大一部分。然而，培养过程耗时且很大一部分报告为阴性。为减少不必要的培养程序并加快阴性结果的报告，需要一种可靠的筛查方法。为此，提交到我们临床微生物实验室的尿液样本同时采用流式细胞术方法（日本Sysmex UF - 1000i）进行筛查。在筛查过程中，对白细胞和细菌临界值的各种组合进行评估表明，分别为30和50/μL的临界值是达到100%阴性预测值（NPV）的最佳阈值，在成年人中培养减少率为44.8%，在6至17岁儿童中为61.9%。凭借上述培养减少率，该筛查方法使常规临床微生物实验室的支出至少节省了24%。由于我们在5岁以下儿童的任何筛查参数组合中都未达到这样的NPV，我们建议对这些患者的所有尿液样本进行培养，不进行筛查步骤。总之，Sysmex UF - 1000i作为一种筛查方法，能够通过在几分钟内为6岁以上儿童和成年人提供阴性结果来提高常规微生物实验室的效率。
