Shafreen Rajamohamed Beema, Seema Siddharthan, Ahamed Abdulazees Parveez, Thajuddin Nooruddin, Ali Alharbi Sulaiman
Molecular Nanomedicine Research Unit, Centre for Nanoscience and Nanotechnology, Sathyabama University, Chennai, 600119, India.
Division of Microbial Biodiversity and Bioenergy, Department of Microbiology, Bharathidasan University, Tiruchirappalli, Tamil Nadu, 600024, India.
Appl Biochem Biotechnol. 2017 Dec;183(4):1351-1361. doi: 10.1007/s12010-017-2503-7. Epub 2017 Jun 1.
Extended spectrum beta lactamase (ESBL) are emerging beta-lactamases in Gram-negative pathogens, causing serious problems in hospitalized patients worldwide. Biofilm mode of virulence has decreased the efficiency of antibiotics used for treatment against ESBL pathogens. Therefore, there is an urgent need for alternative agents such as nanoparticles that can prevent and inhibit the biofilm formation. The aim of the present study was to inhibit the biofilm formed by ESBL-producing Escherichia coli using silver nanoparticles (AgNPs) synthesized with fresh water diatom (Nitzschia palea). AgNPs were characterized using UV-Vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectroscopy (EDX), and XRD. AgNPs at their biofilm inhibitory concentration (BIC) of 300 ng ml significantly reduced the biofilm formed by E. coli. Interestingly, Congo red assay revealed the reduction of curli, essential for biofilm formation in the presence of AgNPs. Light and CLSM examination of the biofilm images also validated that in the presence of AgNPs, the biofilm architecture was disintegrated and the thickness was significantly reduced. Overall, the present study exemplifies the use of AgNPs as a plausible alternative for conventional coating agents on implant devices to prevent and control biofilm-associated urinary tract infections.
超广谱β-内酰胺酶（ESBL）是革兰氏阴性病原体中新兴的β-内酰胺酶，在全球住院患者中引发严重问题。毒力的生物膜模式降低了用于治疗ESBL病原体的抗生素的疗效。因此，迫切需要替代药物，如纳米颗粒，以预防和抑制生物膜形成。本研究的目的是使用由淡水硅藻（菱形藻）合成的银纳米颗粒（AgNP）抑制产ESBL的大肠杆菌形成的生物膜。使用紫外可见光谱、傅里叶变换红外（FTIR）光谱、场发射扫描电子显微镜（FESEM）、能量色散X射线光谱（EDX）和XRD对AgNP进行表征。浓度为300 ng/ml的AgNP在其生物膜抑制浓度（BIC）下显著减少了大肠杆菌形成的生物膜。有趣的是，刚果红试验表明，在存在AgNP的情况下，对生物膜形成至关重要的卷曲菌减少。对生物膜图像的光学和共聚焦激光扫描显微镜（CLSM）检查也证实，在存在AgNP的情况下，生物膜结构被破坏，厚度显著减小。总体而言，本研究例证了AgNP可作为植入装置上传统涂层剂的合理替代品，以预防和控制生物膜相关的尿路感染。
