DTU Nanotech, Technical University of Denmark, Ørsteds Plads 345B, 2800 Lyngby, Denmark.
DTU Biosustain, Technical University of Denmark, Novo Nordisk Foundation Center for Biosustainability, Kogle Allé 6, 2970 Hørsholm, Denmark.
Sci Rep. 2017 Mar 28;7:45264. doi: 10.1038/srep45264.
Pseudomonas aeruginosa is the primary cause of chronic airway infections in cystic fibrosis (CF) patients. Persistent infections are seen from the first P. aeruginosa culture in about 75% of young CF patients, and it is important to discover new ways to detect P. aeruginosa at an earlier stage. The P. aeruginosa biomarker hydrogen cyanide (HCN) contains a triple bond, which is utilized in this study because of the resulting characteristic C≡N peak at 2135 cm in a Raman spectrum. The Raman signal was enhanced by surface-enhanced Raman spectroscopy (SERS) on a Au-coated SERS substrate. After long-term infection, a mutation in the patho-adaptive lasR gene can alter the expression of HCN, which is why it is sometimes not possible to detect HCN in the breath of chronically infected patients. Four P. aeruginosa reference strains and 12 clinical P. aeruginosa strains isolated from CF children were evaluated, and HCN was clearly detected from overnight cultures of all wild type-like isolates and half of the later isolates from the same patients. The clinical impact could be that P. aeruginosa infections could be detected at an earlier stage, because daily breath sampling with an immediate output could be possible with a point-of-care SERS device.
铜绿假单胞菌是囊性纤维化 (CF) 患者慢性气道感染的主要原因。约 75%的年轻 CF 患者在首次培养出铜绿假单胞菌后就会出现持续感染，因此发现更早检测铜绿假单胞菌的新方法非常重要。铜绿假单胞菌生物标志物氰化氢（HCN）含有一个三键，这在本研究中被利用，因为在拉曼光谱中会产生一个特征性的 C≡N 峰，位于 2135cm 处。拉曼信号通过金覆盖的 SERS 基底上的表面增强拉曼光谱 (SERS) 得到增强。在长期感染后，病理适应性 lasR 基因的突变会改变 HCN 的表达，这就是为什么在慢性感染患者的呼吸中有时无法检测到 HCN 的原因。本研究评估了 4 株铜绿假单胞菌参考菌株和 12 株从 CF 儿童中分离出的临床铜绿假单胞菌菌株，从所有类似野生型的 overnight 培养物和同一患者的一半后期培养物中均清晰检测到 HCN。这可能具有临床意义，因为使用即时输出的床边 SERS 设备可以更早地检测到铜绿假单胞菌感染。
