Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel; Department of Otolaryngology-Head and Neck Surgery, Edith Wolfson Hospital, Holon, Israel.
J Biotechnol. 2018 Feb 10;267:45-49. doi: 10.1016/j.jbiotec.2017.12.023. Epub 2017 Dec 29.
Improved easy-to-use diagnostic tools for infections are in strong demand worldwide. Yet, despite dramatic advances in diagnostic technologies, the gold-standard remains culturing. Here we offer an alternative tool demonstrating that a bacterial biosensor can efficiently detect Pseudomonas aeruginosa infections in patients suffering from otitis externa. Detection was based on specific binding between the biosensor and 2-aminoacetophenone (2-AA), a volatile produced by P. aeruginosa in high amounts. We collected pus samples from ears of 26 subjects exhibiting symptoms of otitis externa. Detection of P. aeruginosa using the biosensor was compared to detection using gold-standard culturing assay and to gas-chromatograph-mass-spectrometry (GC-MS) analyses of 2-AA. The biosensor strain test matched the culture assay in 24 samples (92%) and the GC-MS analyses in 25 samples (96%). With this result in hand, we designed a device containing a whole-cell luminescent biosensor combined with a photo-multiplier tube. This device allowed detection of 2-AA at levels as low as 2 nmol, on par with detection level of GC-MS. The results of the described study demonstrate that the volatile 2-AA serves as an effective biomarker for P. aeruginosa in ear infections, and that activation of the biosensor strain by 2-AA provides a unique opportunity to design an easy-to-use device that can specifically detect P. aeruginosa infections.
全球对易于使用的感染诊断工具的需求日益增长。然而，尽管诊断技术取得了显著进展，但金标准仍然是培养。在这里，我们提供了一种替代工具，证明细菌生物传感器可以有效地检测患有外耳炎的患者中的铜绿假单胞菌感染。检测基于生物传感器与 2-乙酰氨基酚（2-AA）之间的特异性结合，2-AA 是铜绿假单胞菌大量产生的挥发性物质。我们从 26 名表现出外耳炎症状的患者的耳朵中采集了脓液样本。使用生物传感器检测铜绿假单胞菌的方法与使用金标准培养测定法和 2-AA 的气相色谱-质谱（GC-MS）分析进行了比较。生物传感器菌株测试在 24 个样本（92%）中与培养测定法相匹配，在 25 个样本（96%）中与 GC-MS 分析相匹配。有了这个结果，我们设计了一个包含全细胞发光生物传感器和光电倍增管的设备。该设备能够检测到低至 2 纳摩尔的 2-AA，与 GC-MS 的检测水平相当。所描述研究的结果表明，挥发性 2-AA 可作为耳感染中铜绿假单胞菌的有效生物标志物，并且 2-AA 对生物传感器菌株的激活为设计一种易于使用的设备提供了独特的机会，该设备可以特异性地检测铜绿假单胞菌感染。
