State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, China.
PLoS One. 2012;7(7):e41137. doi: 10.1371/journal.pone.0041137. Epub 2012 Jul 25.
Exhaled breath condensate (EBC) is increasingly being used as a non-invasive method for disease diagnosis and environmental exposure assessment. By using hydrophobic surface, ice, and droplet scavenging, a simple impaction and condensing based collection method is reported here. Human subjects were recruited to exhale toward the device for 1, 2, 3, and 4 min. The exhaled breath quickly formed into tiny droplets on the hydrophobic surface, which were subsequently scavenged into a 10 µL rolling deionized water droplet. The collected EBC was further analyzed using culturing, DNA stain, Scanning Electron Microscope (SEM), polymerase chain reaction (PCR) and colorimetry (VITEK 2) for bacteria and viruses.Experimental data revealed that bacteria and viruses in EBC can be rapidly collected using the method developed here, with an observed efficiency of 100 µL EBC within 1 min. Culturing, DNA stain, SEM, and qPCR methods all detected high bacterial concentrations up to 7000 CFU/m(3) in exhaled breath, including both viable and dead cells of various types. Sphingomonas paucimobilis and Kocuria variants were found dominant in EBC samples using VITEK 2 system. SEM images revealed that most bacteria in exhaled breath are detected in the size range of 0.5-1.0 µm, which is able to enable them to remain airborne for a longer time, thus presenting a risk for airborne transmission of potential diseases. Using qPCR, influenza A H3N2 viruses were also detected in one EBC sample. Different from other devices restricted solely to condensation, the developed method can be easily achieved both by impaction and condensation in a laboratory and could impact current practice of EBC collection. Nonetheless, the reported work is a proof-of-concept demonstration, and its performance in non-invasive disease diagnosis such as bacterimia and virus infections needs to be further validated including effects of its influencing matrix.
呼出气冷凝物 (EBC) 正越来越多地被用作疾病诊断和环境暴露评估的非侵入性方法。本研究报道了一种简单的基于冲击和冷凝的收集方法，使用疏水性表面、冰和液滴清除来实现。招募人类受试者向设备呼气 1、2、3 和 4 分钟。呼出的气体迅速在疏水性表面上形成微小的液滴，随后被清除到 10µL 滚动去离子水滴中。使用培养、DNA 染色、扫描电子显微镜 (SEM)、聚合酶链反应 (PCR) 和比色法 (VITEK 2) 进一步分析收集的 EBC 以检测细菌和病毒。实验数据表明，使用这里开发的方法可以快速收集 EBC 中的细菌和病毒，在 1 分钟内观察到 100µL EBC 的效率。培养、DNA 染色、SEM 和 qPCR 方法均检测到呼出气体中高浓度的细菌，高达 7000 CFU/m3，包括各种类型的活细胞和死细胞。使用 VITEK 2 系统发现，在 EBC 样本中 Sphingomonas paucimobilis 和 Kocuria 变体占主导地位。SEM 图像显示，呼出气体中的大多数细菌都在 0.5-1.0µm 的大小范围内被检测到，这使它们能够在空中停留更长时间，从而增加了潜在疾病空气传播的风险。使用 qPCR，还在一个 EBC 样本中检测到甲型 H3N2 流感病毒。与其他仅局限于冷凝的设备不同，该方法可以在实验室中通过冲击和冷凝轻松实现，并可能影响当前的 EBC 收集实践。然而，所报道的工作只是一个概念验证演示，其在非侵入性疾病诊断（如菌血症和病毒感染）中的性能需要进一步验证，包括其影响基质的影响。
