Health Department, El Colegio de la Frontera Sur (ECOSUR), San Cristobal de Las Casas, Chiapas 29290, Mexico.
The Network GRAAL (Grups de Recerca d'America i Africa Llatines), El Colegio de La Frontera Sur (ECOSUR), San Cristobal de Las Casas, Chiapas 29290, Mexico.
Biosensors (Basel). 2022 Jan 7;12(1):29. doi: 10.3390/bios12010029.
Despite its reduced sensitivity, sputum smear microscopy (SSM) remains the main diagnostic test for detecting tuberculosis in many parts of the world. A new diagnostic technique, the magnetic nanoparticle-based colorimetric biosensing assay (NCBA) was optimized by evaluating different concentrations of glycan-functionalized magnetic nanoparticles (GMNP) and Tween 80 to improve the acid-fast bacilli (AFB) count. Comparative analysis was performed on 225 sputum smears: 30 with SSM, 107 with NCBA at different GMNP concentrations, and 88 with NCBA-Tween 80 at various concentrations and incubation times. AFB quantification was performed by adding the total number of AFB in all fields per smear and classified according to standard guidelines (scanty, 1+, 2+ and 3+). Smears by NCBA with low GMNP concentrations (≤1.5 mg/mL) showed higher AFB quantification compared to SSM. Cell enrichment of sputum samples by combining NCBA-GMNP, incubated with Tween 80 (5%) for three minutes, improved capture efficiency and increased AFB detection up to 445% over SSM. NCBA with Tween 80 offers the opportunity to improve TB diagnostics, mainly in paucibacillary cases. As this method provides biosafety with a simple and inexpensive methodology that obtains results in a short time, it might be considered as a point-of-care TB diagnostic method in regions where resources are limited.
尽管其敏感性降低，痰涂片显微镜检查（SSM）仍然是世界许多地区检测结核病的主要诊断测试。一种新的诊断技术，基于磁性纳米粒子的比色生物传感测定法（NCBA）通过评估不同浓度的糖基化磁性纳米粒子（GMNP）和吐温 80 来优化，以提高抗酸杆菌（AFB）计数。对 225 个痰涂片进行了比较分析：30 个用 SSM，107 个用不同 GMNP 浓度的 NCBA，88 个用 NCBA-Tween 80 在不同浓度和孵育时间。通过添加每个涂片所有视野中的总 AFB 数量进行 AFB 定量，并根据标准指南进行分类（稀少，1+，2+和 3+）。与 SSM 相比，低 GMNP 浓度（≤1.5mg/mL）的 NCBA 显示出更高的 AFB 定量。通过将 NCBA-GMNP 与吐温 80（5%）结合进行细胞富集，孵育三分钟，提高了捕获效率，并将 AFB 检测提高了 445%，高于 SSM。NCBA 加吐温 80 提供了改善结核病诊断的机会，主要是在少菌病例中。由于该方法具有生物安全性，且方法简单、成本低廉，可在短时间内获得结果，因此在资源有限的地区，可考虑将其作为一种即时检测结核病的诊断方法。
