Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, Ste-Anne-de-Bellevue, Quebec, H9X 3V9, Canada.
Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Université de Montréal, Faculté de Médecine Vétérinaire, Saint-Hyacinthe, Québec, J2S 2M2, Canada.
Sci Rep. 2020 Jun 4;10(1):9145. doi: 10.1038/s41598-020-65973-3.
Legionella pneumophila (Lp) is a water borne bacterium causing Legionnaires' Disease (LD) in humans. Rapid detection of Lp in water system is essential to reduce the risk of LD outbreaks. The methods currently available require expert skills and are time intensive, thus delaying intervention. In situ detection of Lp by biosensor would allow rapid implementation of control strategies. To this end, a biorecognition element is required. Aptamers are considered promising biorecognition molecules for biosensing. Aptamers are short oligonucleotide sequence folding into a specific structure and are able to bind to specific molecules. Currently, no aptamer and thus no aptamer-based technology exists for the detection of Lp. In this study, Systemic Evolution of Ligands through EXponential enrichment (SELEX) was used to identify aptamers binding specifically to Lp. Ten rounds of positive selection and two rounds of counter-selection against two Pseudomonas species were performed. Two aptamers binding strongly to Lp were identified with K of 116 and 135 nM. Binding specificity of these two aptamers to Lp was confirmed by flow cytometry and fluorescence microscopy. Therefore, these two aptamers are promising biorecognition molecules for the detection of Lp in water systems.
嗜肺军团菌（Lp）是一种水生细菌，可导致人类军团病（LD）。快速检测水中的 Lp 对于降低 LD 爆发的风险至关重要。目前可用的方法需要专业技能并且耗时，因此会延迟干预。通过生物传感器进行原位检测可以快速实施控制策略。为此，需要生物识别元件。适体被认为是生物传感的有前途的生物识别分子。适体是短的寡核苷酸序列折叠成特定的结构，并且能够与特定的分子结合。目前，尚无针对 Lp 检测的适体，因此也没有基于适体的技术。在这项研究中，通过指数富集的配体系统进化（SELEX）来鉴定特异性结合 Lp 的适体。对两种假单胞菌进行了十轮正选择和两轮反选择。鉴定出两种与 Lp 结合力强的适体，其 Kd 值分别为 116 和 135 nM。通过流式细胞术和荧光显微镜证实了这两种适体与 Lp 的结合特异性。因此，这两种适体是用于检测水系统中 Lp 的有前途的生物识别分子。
