PDF(Pubmed)
Abstract：
BACKGROUND: A rapid screening test for urinary tract infections (UTIs) in children is needed to avoid unnecessary cultures and provide prompt reports to make appropriate clinical decisions. We have evaluated for the first time the performance of the Sysmex UF-5000 flow cytometer as a screening tool for UTIs in children.
METHODS: This study included 4445 pediatric patients, with urinary sediment and urine culture data collected from January 2020 to September 2023. The Sysmex UF-5000 analyzer was utilized to measure urine white blood cell (WBC) and bacteria (BACT), with the findings being compared to the culture results.
RESULTS: At ≥ 104 colony-forming unit (CFU)/mL, 513 samples were culture-positive (400 samples presented 104-105 CFU/mL, and 113 demonstrated ≥ 105 CFU/mL bacterial growth). Optimal indicators for positive cultures were BACT counts of 92.2/μL (AUC: 0.944) and WBC counts of 40.8/μL (AUC:0.863). False negative rate were 0.9% when using a 7.8 bacteria/μL cut-off and avoiding unnecessary cultures in 28.1%. The UF-5000 has a higher consistency rate for Gram-negative (GN) bacteria (90.3%) than Gram-positive (GP) bacteria (86.8%). For samples with 105 CFU/mL, UF-5000\'s Bacteria -Information flags showed superior concordance for samples with 104-105 CFU/mL bacteria.
CONCLUSIONS: Screening pediatric urine cultures with the UF-5000 showed potential application value in identifying negative cultures and significant bacterial growth, although performance may vary depending on the study population. Furthermore, detecting Gram typing aids in guiding early clinical empirical medication, particularly for UTIs caused by GN bacteria.
METHODS: This study included 4445 pediatric patients, with urinary sediment and urine culture data collected from January 2020 to September 2023. The Sysmex UF-5000 analyzer was utilized to measure urine white blood cell (WBC) and bacteria (BACT), with the findings being compared to the culture results.
RESULTS: At ≥ 104 colony-forming unit (CFU)/mL, 513 samples were culture-positive (400 samples presented 104-105 CFU/mL, and 113 demonstrated ≥ 105 CFU/mL bacterial growth). Optimal indicators for positive cultures were BACT counts of 92.2/μL (AUC: 0.944) and WBC counts of 40.8/μL (AUC:0.863). False negative rate were 0.9% when using a 7.8 bacteria/μL cut-off and avoiding unnecessary cultures in 28.1%. The UF-5000 has a higher consistency rate for Gram-negative (GN) bacteria (90.3%) than Gram-positive (GP) bacteria (86.8%). For samples with 105 CFU/mL, UF-5000\'s Bacteria -Information flags showed superior concordance for samples with 104-105 CFU/mL bacteria.
CONCLUSIONS: Screening pediatric urine cultures with the UF-5000 showed potential application value in identifying negative cultures and significant bacterial growth, although performance may vary depending on the study population. Furthermore, detecting Gram typing aids in guiding early clinical empirical medication, particularly for UTIs caused by GN bacteria.
摘要：
背景：需要对儿童进行尿路感染（UTI）的快速筛查测试，以避免不必要的培养并提供及时的报告以做出适当的临床决定。我们首次评估了SysmexUF-5000流式细胞仪作为儿童UTI筛查工具的性能。
方法：这项研究包括4445名儿科患者，从2020年1月至2023年9月收集尿沉渣和尿培养数据。SysmexUF-5000分析仪用于测量尿白细胞（WBC）和细菌（BACT），将研究结果与培养结果进行比较。
结果：在≥104菌落形成单位（CFU）/mL时，513个样本为培养阳性(400个样本呈现104-105CFU/mL，113显示≥105CFU/mL细菌生长）。阳性培养物的最佳指标是92.2/μL的BACT计数(AUC:0.944)和40.8/μL的WBC计数(AUC:0.863)。当使用7.8细菌/μL切断值并避免28.1％的不必要培养时，假阴性率为0.9％。UF-5000对革兰氏阴性（GN）细菌的稠度（90.3％）高于革兰氏阳性（GP）细菌（86.8％）。对于105CFU/mL的样品，UF-5000的细菌-信息标志显示具有104-105CFU/mL细菌的样品具有优异的一致性。
结论：用UF-5000筛选儿科尿液培养物在鉴定阴性培养物和显着细菌生长方面具有潜在的应用价值，尽管性能可能因研究人群而异。此外，检测革兰氏分型有助于指导早期临床经验用药，特别是由GN细菌引起的UTI。
方法：这项研究包括4445名儿科患者，从2020年1月至2023年9月收集尿沉渣和尿培养数据。SysmexUF-5000分析仪用于测量尿白细胞（WBC）和细菌（BACT），将研究结果与培养结果进行比较。
结果：在≥104菌落形成单位（CFU）/mL时，513个样本为培养阳性(400个样本呈现104-105CFU/mL，113显示≥105CFU/mL细菌生长）。阳性培养物的最佳指标是92.2/μL的BACT计数(AUC:0.944)和40.8/μL的WBC计数(AUC:0.863)。当使用7.8细菌/μL切断值并避免28.1％的不必要培养时，假阴性率为0.9％。UF-5000对革兰氏阴性（GN）细菌的稠度（90.3％）高于革兰氏阳性（GP）细菌（86.8％）。对于105CFU/mL的样品，UF-5000的细菌-信息标志显示具有104-105CFU/mL细菌的样品具有优异的一致性。
结论：用UF-5000筛选儿科尿液培养物在鉴定阴性培养物和显着细菌生长方面具有潜在的应用价值，尽管性能可能因研究人群而异。此外，检测革兰氏分型有助于指导早期临床经验用药，特别是由GN细菌引起的UTI。
