Department of Urology, Stanford University School of Medicine, Stanford, CA, USA; Department of Urology, Campus Biomedico University of Rome, Rome, Italy.
Department of Urology, Stanford University School of Medicine, Stanford, CA, USA.
Eur Urol Focus. 2017 Apr;3(2-3):293-299. doi: 10.1016/j.euf.2015.12.010. Epub 2016 Jan 15.
Standard diagnosis of urinary tract infection (UTI) via urine culture for pathogen identification (ID) and antimicrobial susceptibility testing (AST) takes 2-3 d. This delay results in empiric treatment and contributes to the misuse of antibiotics and the rise of resistant pathogens. A rapid diagnostic test for UTI may improve patient care and antibiotic stewardship.
To develop and validate an integrated biosensor assay for UTI diagnosis, including pathogen ID and AST, with determination of the minimum inhibitory concentration (MIC) for ciprofloxacin.
DESIGN, SETTING, AND PARTICIPANTS: Urine samples positive for Enterobacteriaceae (n=84) or culture-negative (n=23) were obtained from the Stanford Clinical Microbiology Laboratory between November 2013 and September 2014. Each sample was diluted and cultured for 5h with and without ciprofloxacin, followed by quantitative detection of bacterial 16S rRNA using a single electrochemical biosensor array functionalized with a panel of complementary DNA probes. Pathogen ID was determined using universal bacterial, Enterobacteriaceae (EB), and pathogen-specific probes. Phenotypic AST with ciprofloxacin MIC was determined using an EB probe to measure 16S rRNA levels as a function of bacterial growth.
Electrochemical signals for pathogen ID at 6 SD over background were considered positive. An MIC signal of 0.4 log units lower than the no-antibiotic control indicated sensitivity. Results were compared to clinical microbiology reports.
For pathogen ID, the assay had 98.5% sensitivity, 96.6% specificity, 93.0% positive predictive value, and 99.3% negative predictive value. For ciprofloxacin MIC the categorical and essential agreement was 97.6%. Further automation, testing of additional pathogens and antibiotics, and a full prospective study will be necessary for translation to clinical use.
The integrated biosensor platform achieved microbiological results including MIC comparable to standard culture in a significantly shorter assay time. Further assay automation will allow clinical translation for rapid molecular diagnosis of UTI.
We have developed and validated a biosensor test for rapid diagnosis of urinary tract infections. Clinical translation of this device has the potential to significantly expedite and improve treatment of urinary tract infections.
通过尿液培养进行病原体鉴定（ID）和抗菌药物敏感性测试（AST）来诊断尿路感染（UTI）的标准方法需要 2-3 天。这种延迟导致经验性治疗，并导致抗生素的滥用和耐药病原体的出现。UTI 的快速诊断测试可能会改善患者的治疗效果和抗生素管理。
开发和验证一种用于 UTI 诊断的集成生物传感器检测方法，包括病原体 ID 和 AST，以及确定环丙沙星的最低抑菌浓度（MIC）。
设计、设置和参与者：从 2013 年 11 月至 2014 年 9 月，从斯坦福临床微生物学实验室获得了大肠埃希菌阳性（n=84）或培养阴性（n=23）的尿液样本。每个样本均进行稀释并在 5 小时内与和不与环丙沙星一起培养，然后使用功能化有多组互补 DNA 探针的单个电化学生物传感器阵列对细菌 16S rRNA 进行定量检测。使用通用细菌、肠杆菌科（EB）和病原体特异性探针来确定病原体 ID。使用 EB 探针进行环丙沙星 MIC 的表型 AST，以测量作为细菌生长函数的 16S rRNA 水平。
病原体 ID 的电化学信号超过背景的 6 个标准差被认为是阳性的。MIC 信号比无抗生素对照低 0.4 个对数单位表示敏感。结果与临床微生物学报告进行了比较。
对于病原体 ID，该检测方法的敏感性为 98.5%，特异性为 96.6%，阳性预测值为 93.0%，阴性预测值为 99.3%。对于环丙沙星 MIC，分类和主要一致性为 97.6%。进一步的自动化、对其他病原体和抗生素的测试以及全面的前瞻性研究将是将其转化为临床应用所必需的。
集成生物传感器平台实现了微生物学结果，包括 MIC，与标准培养相比，其检测时间明显缩短。进一步的检测自动化将使快速分子诊断 UTI 的临床转化成为可能。
我们已经开发并验证了一种用于快速诊断尿路感染的生物传感器测试。该设备的临床转化有可能显著加快和改善尿路感染的治疗效果。
