Foudeh Amir M, Trigui Hana, Mendis Nilmini, Faucher Sebastien P, Veres Teodor, Tabrizian Maryam
Department of Biomedical Engineering, Faculty of Medicine, McGill University, 3775 University Street, Montreal, QC, H3A 2B4, Canada.
Anal Bioanal Chem. 2015 Jul;407(18):5541-5. doi: 10.1007/s00216-015-8726-y. Epub 2015 May 3.
Legionellosis is a very devastating disease worldwide mainly due to unpredictable outbreaks in man-made water systems. Developing a highly specific and sensitive rapid detection system that detects only metabolically active bacteria is a main priority for water quality assessment. We previously developed a versatile technique for sensitive and specific detection of synthetic RNA. In the present work, we further investigated the performance of the developed biosensor for detection of Legionella pneumophila in complex environmental samples, particularly those containing protozoa. The specificity and sensitivity of the detection system were verified using total RNA extracted from L. pneumophila in spiked water co-cultured with amoebae. We demonstrated that the expression level of ribosomal RNA (rRNA) is extremely dependent on the environmental conditions. The presence of amoebae with L. pneumophila, especially in nutrition-deprived samples, increased the amount of L. pneumophila 15-fold after 1 week as measured through the expression of 16s rRNA. Using the developed surface plasmon resonance imaging (SPRi) detection method, we were also able to successfully detect L. pneumophila within 3 h, both in the presence and absence of amoebae in the complex environmental samples obtained from a cooling water tower. These findings suggest that the developed biosensing system is a viable method for rapid, real-time and effective detection not only for L. pneumophila in environmental samples but also to assess the risk associated with the use of water contaminated with other pathogens.
军团菌病在全球范围内是一种极具破坏性的疾病，主要原因是人造水系统中不可预测的疫情爆发。开发一种仅能检测代谢活跃细菌的高度特异性和灵敏的快速检测系统是水质评估的首要任务。我们之前开发了一种用于灵敏且特异性检测合成RNA的通用技术。在本研究中，我们进一步研究了所开发的生物传感器在复杂环境样品（特别是含有原生动物的样品）中检测嗜肺军团菌的性能。使用从与变形虫共培养的加标水中的嗜肺军团菌提取的总RNA，验证了检测系统的特异性和灵敏性。我们证明核糖体RNA（rRNA）的表达水平极度依赖于环境条件。嗜肺军团菌与变形虫共存，尤其是在营养缺乏的样品中，通过16s rRNA的表达测量，1周后嗜肺军团菌的数量增加了15倍。使用所开发的表面等离子体共振成像（SPRi）检测方法，我们还能够在3小时内成功检测到从冷却塔获得的复杂环境样品中存在和不存在变形虫情况下的嗜肺军团菌。这些发现表明，所开发的生物传感系统不仅是一种用于快速、实时和有效检测环境样品中嗜肺军团菌的可行方法，也是一种评估与使用受其他病原体污染的水相关风险的可行方法。
