Programa de Pós-Graduação Em Ciências Biológicas, Universidade Federal de Pernambuco, 50670-901, Recife, PE, Brazil.
Programa de Pós-Graduação Em Inovação Terapêutica, Universidade Federal de Pernambuco, 50670-901, Recife, PE, Brazil; Laboratório de Biodispositivos Nanoestruturados, Departamento de Bioquímica, Universidade Federal de Pernambuco, 50670-901, Recife, PE, Brazil.
Talanta. 2020 Dec 1;220:121375. doi: 10.1016/j.talanta.2020.121375. Epub 2020 Jul 11.
Fungi stand out as primary pathogens present in healthcare-acquired infections, presenting an increased number of cases even using appropriate antifungal therapy. Candida spp. is a predominant microorganism among several fungal pathogens present in the healthcare setting. Candidemia and candidiasis are fungal infections responsible for high morbidity and mortality among ill patients in hospitals. It is noticeable that prolonged hospital stays lead to a higher economic impact and increased risk for developing secondary fungal or even bacterial infections. New fast and sensitive approaches for the detection of Candida species is highly required. Electrochemical biosensors are an excellent alternative to conventional techniques by combining fast analyte detection, low cost, and the possibility of miniaturization. Lectins are carbohydrate-binding proteins with the capability to reach out to the microorganism cell wall. In this work, we proposed the development of an impedimetric biosensor for Candida spp. based on Concanavalin A (ConA) and wheat germ agglutinin (WGA) as recognition agents of the yeast cells. Atomic force microscopy images indicate changes in the biosensor surface after assembly of the molecules and exposure to fungal samples. Electrochemical impedance spectroscopy results revealed a proportional increase of charge transfer resistance (R) as fungal CFU increased, where four Candida species were evaluated (Candida krusei, Candida tropicalis, Candida parapsilosis and Candida albicans). The biosensor is useful to differentiate Candida spp. with a detection limit between 10 to 10 CFU mL. The obtained biosensor appears as an innovative candidate for the detection and differentiation of pathogenic Candida spp.
真菌是医院获得性感染的主要病原体，即使使用适当的抗真菌治疗，也会出现越来越多的病例。念珠菌属是医院环境中存在的几种真菌病原体中的主要微生物。念珠菌血症和念珠菌病是导致医院中患病患者发病率和死亡率高的真菌感染。值得注意的是，延长住院时间会导致更高的经济影响和更高的继发性真菌感染甚至细菌感染风险。因此，非常需要新的快速和敏感的方法来检测念珠菌属。电化学生物传感器通过结合快速分析物检测、低成本和小型化的可能性，是传统技术的极好替代品。凝集素是具有识别微生物细胞壁能力的碳水化合物结合蛋白。在这项工作中，我们提出了基于刀豆球蛋白 A（ConA）和麦胚凝集素（WGA）的念珠菌属（Candida spp.）的阻抗生物传感器的开发，作为酵母细胞的识别剂。原子力显微镜图像表明，在组装分子和暴露于真菌样品后，生物传感器表面发生了变化。电化学阻抗谱结果表明，随着真菌 CFU 的增加，电荷转移电阻（R）呈比例增加，其中评估了四种念珠菌属（克鲁斯念珠菌、热带念珠菌、近平滑念珠菌和白色念珠菌）。该生物传感器可用于区分念珠菌属，检测限在 10 到 10 CFU mL 之间。所获得的生物传感器似乎是一种用于检测和区分致病性念珠菌属的创新候选物。
