Bayraç Abdullah Tahir, Donmez Sultan Ilayda
Department of Bioengineering, Karamanoglu Mehmetbey University, Yunus Emre Campus, 70100 Karaman, Turkey.
Department of Bioengineering, Karamanoglu Mehmetbey University, Yunus Emre Campus, 70100 Karaman, Turkey.
Anal Biochem. 2018 Sep 1;556:91-98. doi: 10.1016/j.ab.2018.06.024. Epub 2018 Jun 28.
Pneumococci are one of the leading causes of infections throughout the world causing problems mainly in children, elderly, and immune-deficient patients. In recent years antibiotic resistant Streptococcus pneumoniae strains become widespread. Therefore simple, rapid, and specific detection methods are needed for public health. In this study, DNA aptamer probes against S. pneumoniae were selected using bacterial Systematic Evolution of Ligands by Exponential Enrichment (SELEX) and these probes were integrated in to a graphene oxide (GO) based fluorescent assay. Among the tested aptamers three candidates Lyd-1, Lyd-2 and Lyd-3 showed K values of 844.7 ± 123.6, 1984.8 ± 347.5, and 661.8 ± 111.3 nM, respectively. These candidates showed binding affinity to S. pneumoniae and no specific binding to the bacteria used in negative selection. The binding of aptamers were showed by fluorescence spectroscopy and flow cytometry. GO based label-free fluorescent assay developed using Lyd-3 aptamer had a unique detection limit of 15 cfu mL. Thus we believe that the selected aptamers and fabricated GO based assay has potential to be used in the detection of S. pneumoniae. Selected aptamers selectively bind to S. pneumonia with anti-pneumococcal potential and holds great potential to be used as molecular probes for identifying and targeting.
肺炎球菌是全球感染的主要病因之一，主要在儿童、老年人和免疫缺陷患者中引发问题。近年来，耐抗生素的肺炎链球菌菌株广泛传播。因此，公共卫生领域需要简单、快速且特异的检测方法。在本研究中，通过指数富集的配体系统进化技术（SELEX）筛选出针对肺炎链球菌的DNA适配体探针，并将这些探针整合到基于氧化石墨烯（GO）的荧光检测方法中。在所测试的适配体中，三个候选者Lyd-1、Lyd-2和Lyd-3的K值分别为844.7±123.6、1984.8±347.5和661.8±111.3 nM。这些候选者对肺炎链球菌表现出结合亲和力，对阴性选择中使用的细菌无特异性结合。适配体的结合通过荧光光谱和流式细胞术得以展示。使用Lyd-3适配体开发的基于GO的无标记荧光检测方法具有独特的检测限，为15 cfu/mL。因此，我们认为所筛选的适配体以及构建的基于GO的检测方法有潜力用于肺炎链球菌的检测。所筛选的适配体选择性地与肺炎链球菌结合，具有抗肺炎球菌的潜力，并且作为识别和靶向的分子探针具有巨大潜力。
