Liu Dejing, Hu Bo, Peng Dingfa, Lu Shan, Gao Shunxiang, Li Zhengang, Wang Lianghua, Jiao Binghua
Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Second Military Medical University Shanghai 200433 People's Republic of China.
Department of Marine Biomedicine and Polar Medicine, Naval Special Medical Center Shanghai People's Republic of China.
RSC Adv. 2020 Apr 22;10(27):15997-16008. doi: 10.1039/c9ra10733a. eCollection 2020 Apr 21.
is a ubiquitous marine bacterium that may cause rapid and deadly infection, threatening lives of people living around natural bodies of water, especially in coastal regions. However, traditional culture-based methods are time-consuming and unable to detect Viable But Non-Culturable (VBNC) cells. In this work, we isolated a batch of detection aptamers specifically binding to in all culture status. With traditional whole bacteria-SELEX (Systematic Evolution of Ligands by EXponential enrichment), flow cytometer analysis and imaging, we identify 18 candidates and validated two of them (V8 and V13) as applicable aptamers. Their truncated sequences also showed comparable performance. The dissociation constant (KD) value of V8 is shown to be as low as 11.22 ± 1.32 nM. Optimal aptamers V8 and V13 are also validated to be effective to detect different strains under different binding environments using flow cytometry. As for detection parameters, the LOD of the V8 from cytometry is 29.96 CFU mL, and the linear range is 10-5 × 10 CFU mL. This is the first case demonstrating that aptamers can detect the existence of VBNC bacteria as well as live bacteria.
是一种普遍存在的海洋细菌,可能导致快速且致命的感染,威胁着生活在天然水体周围的人们的生命,尤其是在沿海地区。然而,传统的基于培养的方法耗时且无法检测到活的但不可培养(VBNC)的细胞。在这项工作中,我们分离出了一批在所有培养状态下都能特异性结合的检测适体。通过传统的全细菌SELEX(指数富集配体系统进化)、流式细胞仪分析和成像,我们鉴定出18个候选适体,并验证了其中两个(V8和V13)为适用的适体。它们的截短序列也表现出相当的性能。V8的解离常数(KD)值低至11.22±1.32 nM。还通过流式细胞术验证了最佳适体V8和V13在不同结合环境下对检测不同菌株有效。至于检测参数,流式细胞仪检测V8的检测限为29.96 CFU/mL,线性范围为10 - 5×10 CFU/mL。这是首次证明适体能够检测VBNC细菌以及活细菌存在的案例。