Saranya Elangovan, Vishwakarma Archana, Mandrekar Kiran K, Leela Kakithakara Vajravelu, Ramya Mohandass
Department of Genetic Engineering, SRM Institute of Science and Technology, Kattankulathur, Chengalpattu, Chennai, Tamil Nadu, 603 203, India.
Department of Chemistry, SRM Institute of Science and Technology, Kattankulathur, Chengalpattu, Chennai, Tamil Nadu, 603 203, India.
World J Microbiol Biotechnol. 2024 Dec 3;40(12):401. doi: 10.1007/s11274-024-04210-9.
Leptospirosis is a neglected zoonosis caused by a pathogenic spirochete Leptospira. Diagnosis of leptospirosis in the early stage is difficult and can be easily confused with other infections. The existing detection methods are considered chronophagous and labor-intensive. Leptospira survives in the kidney tubules of reservoir animals such as rodents and shed into the environment through their urine. In this study, we developed an Aptamer-DNAzyme-based biosensor for detecting pathogenic Leptospira in environmental water samples. The cell-specific aptamer with an extensive affinity binds to the cell surface proteins to detect the Leptospira interrogans. The DNAzyme that mimics as a peroxidase enzyme, acts as a transducing agent in the colorimetric reaction positively conditioned by the presence of L. interrogans. The Leptospira-specific aptamer coupled with DNAzyme is coated onto carbon nanotubes, to provide a cost-effective nanomaterial-based detection platform. L. interrogans contamination in the samples is detected with a color change of a peroxidase substrate, ABTS. The dissociation constant of the aptazyme was found to be 356.6 nM. The aptazyme system was able to detect up to 119 CFU/mL of L. interrogans exhibiting a high range of selectivity towards the pathogenic spirochete. This simple detection methodology makes the system promising for the environmental monitoring of L. interrogans.
钩端螺旋体病是一种由致病性螺旋体钩端螺旋体引起的被忽视的人畜共患病。钩端螺旋体病的早期诊断困难，且容易与其他感染混淆。现有的检测方法耗时且费力。钩端螺旋体在啮齿动物等储存宿主动物的肾小管中存活，并通过它们的尿液排入环境。在本研究中，我们开发了一种基于适体-脱氧核酶的生物传感器，用于检测环境水样中的致病性钩端螺旋体。具有广泛亲和力的细胞特异性适体与细胞表面蛋白结合，以检测问号钩端螺旋体。模拟过氧化物酶的脱氧核酶在由问号钩端螺旋体的存在正向调节的比色反应中充当传感元件。与脱氧核酶偶联的钩端螺旋体特异性适体被包被在碳纳米管上，以提供一个具有成本效益的基于纳米材料的检测平台。通过过氧化物酶底物ABTS的颜色变化检测样品中的问号钩端螺旋体污染。发现适体-脱氧核酶的解离常数为356.6 nM。适体-脱氧核酶系统能够检测高达119 CFU/mL的问号钩端螺旋体，对致病性螺旋体表现出高度的选择性。这种简单的检测方法使该系统有望用于问号钩端螺旋体的环境监测。
