Nanomedicine Lab, Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India.
J Mater Chem B. 2020 Aug 7;8(29):6296-6306. doi: 10.1039/d0tb00731e. Epub 2020 May 22.
Globally, rapid development of antibiotic resistance amongst pathogens has led to limited treatment options and high indirect costs to health management. There is a need to avoid misuse of available antibiotics and to develop rapid, affordable and accessible diagnostic technologies to detect drug resistance even in resource limited settings. This study reports the development of instrument-free point-of-care devices for detection of antibiotic resistance for rapid diagnosis of drug resistance in the penicillin, cephalosporin and carbapenem groups of antibiotics. The simple paper-based devices for flow through assay determine the presence of resistant bacteria in a sample by a visible colour change within 30 minutes. At the center of this technology is the unique sensing nanomaterial comprising of core-shell nanoparticles layered with specific antibiotics. The core is comprised of chitosan nanoparticles of size ∼15 nm coated with the starch-iodine indicator to form a shell increasing the size to ∼47 nm. The test strip is coated with the nanoparticles, air-dried and overlayed with the required antibiotic. In the presence of penicillin, cephalosporin and carbapenem resistant bacteria, the core-shell nanoparticles undergo a visible colour change from blue to white. The core-shell nanoparticles were deposited on paper to form a point-of-care device. Devices were developed to screen for three main classes of antibiotics namely penicillins, cephalosporins and carbapenems. The devices were validated using standard resistant and susceptible ATCC strains in three different sample types, pure colony, broth culture and saline suspensions. The change of colour from blue to white was considered a positive test. The time of detection was found to be 30 min, while the limit of detection was 10 cfu ml. The device exhibited 100% sensitivity and specificity with known resistant and susceptible cultures not only from pure colonies but also from direct samples of spiked saline suspensions with graded confounding factors of albumin, glucose, and urea. The inter-device reproducibility and storage stability of the devices was established. The developed point-of-care devices have potential as screening devices for antimicrobial resistance.
全球范围内，病原体对抗生素的耐药性迅速发展，导致治疗选择有限，卫生管理成本高昂。因此，有必要避免滥用现有抗生素，并开发快速、经济实惠且易于获取的诊断技术，以便在资源有限的情况下检测耐药性。本研究报告了无需仪器的即时检测设备的开发，用于检测青霉素类、头孢菌素类和碳青霉烯类抗生素的耐药性，以便快速诊断耐药性。这种基于纸张的简单即时检测设备可通过 30 分钟内的可见颜色变化来确定样本中是否存在耐药菌。该技术的核心是由包含特定抗生素的核壳纳米粒子组成的独特传感纳米材料。该核由尺寸约为 15nm 的壳聚糖纳米粒子组成，表面涂有淀粉-碘指示剂形成壳层，从而将尺寸增加到约 47nm。测试条涂有纳米粒子，风干后再涂有所需的抗生素。当存在耐青霉素、头孢菌素和碳青霉烯类抗生素的细菌时，核壳纳米粒子会发生从蓝色到白色的可见颜色变化。核壳纳米粒子被沉积在纸上，形成即时检测设备。该设备用于筛选三类主要抗生素，即青霉素类、头孢菌素类和碳青霉烯类。该设备在三种不同样本类型（纯菌落、肉汤培养物和生理盐水悬浮液）中使用标准耐药和敏感 ATCC 菌株进行了验证。将颜色从蓝色变为白色视为阳性测试。检测时间为 30 分钟，检测限为 10cfu/ml。该设备对已知的耐药和敏感培养物均具有 100%的灵敏度和特异性，不仅对纯菌落，而且对直接取自含白蛋白、葡萄糖和尿素等分级混杂因素的生理盐水悬浮液的样本均有此效果。该设备的批内和存储稳定性也得到了证实。开发的即时检测设备有望成为用于检测抗菌药物耐药性的筛选设备。
