Ansari Mohammad Azam, Khan Haris Manzoor, Khan Aijaz Ahmed, Cameotra Swaranjit Singh, Saquib Quaiser, Musarrat Javed
Nanotechnology and Antimicrobial Drug Resistance Research Laboratory, Department of Microbiology, Jawaharlal Nehru Medical College and Hospital, Aligarh Muslim University, Aligarh, U.P., India.
J Basic Microbiol. 2014 Jul;54(7):688-99. doi: 10.1002/jobm.201300748. Epub 2014 Jan 9.
Clinical isolates (n = 55) of Pseudomonas aeruginosa were screened for the extended spectrum β-lactamases and metallo-β-lactamases activities and biofilm forming capability. The aim of the study was to demonstrate the antibiofilm efficacy of gum arabic capped-silver nanoparticles (GA-AgNPs) against the multi-drug resistant (MDR) biofilm forming P. aeruginosa. The GA-AgNPs were characterized by UV-spectroscopy, X-ray diffraction, and high resolution-transmission electron microscopy analysis. The isolates were screened for their biofilm forming ability, using the Congo red agar, tube method and tissue culture plate assays. The biofilm forming ability was further validated and its inhibition by GA-AgNPs was demonstrated by performing the scanning electron microscopy (SEM) and confocal laser scanning microscopy. SEM analysis of GA-AgNPs treated bacteria revealed severely deformed and damaged cells. Double fluorescent staining with propidium iodide and concanavalin A-fluorescein isothiocyanate concurrently detected the bacterial cells and exopolysaccharides (EPS) matrix. The CLSM results exhibited the GA-AgNPs concentration dependent inhibition of bacterial growth and EPS matrix of the biofilm colonizers on the surface of plastic catheters. Treatment of catheters with GA-AgNPs at 50 µg ml(-1) has resulted in 95% inhibition of bacterial colonization. This study elucidated the significance of GA-AgNPs, as the next generation antimicrobials, in protection against the biofilm mediated infections caused by MDR P. aeruginosa. It is suggested that application of GA-AgNPs, as a surface coating material for dispensing antibacterial attributes to surgical implants and implements, could be a viable approach for controlling MDR pathogens after adequate validations in clinical settings.
对55株铜绿假单胞菌临床分离株进行了超广谱β-内酰胺酶和金属β-内酰胺酶活性以及生物膜形成能力的筛选。本研究的目的是证明阿拉伯胶包被的银纳米颗粒(GA-AgNPs)对多药耐药(MDR)生物膜形成铜绿假单胞菌的抗生物膜功效。通过紫外光谱、X射线衍射和高分辨率透射电子显微镜分析对GA-AgNPs进行了表征。使用刚果红琼脂、试管法和组织培养板试验筛选分离株的生物膜形成能力。通过扫描电子显微镜(SEM)和共聚焦激光扫描显微镜进一步验证生物膜形成能力并证明GA-AgNPs对其的抑制作用。对GA-AgNPs处理的细菌进行SEM分析,结果显示细胞严重变形和受损。用碘化丙啶和伴刀豆球蛋白A-异硫氰酸荧光素进行双重荧光染色可同时检测细菌细胞和胞外多糖(EPS)基质。CLSM结果显示GA-AgNPs对塑料导管表面生物膜定植菌的细菌生长和EPS基质具有浓度依赖性抑制作用。用50μg/ml的GA-AgNPs处理导管可导致95%的细菌定植抑制率。本研究阐明了GA-AgNPs作为下一代抗菌剂在预防由MDR铜绿假单胞菌引起的生物膜介导感染方面的重要性。建议将GA-AgNPs作为一种表面涂层材料应用于外科植入物和器具以赋予其抗菌特性,这在临床环境中经过充分验证后可能是控制MDR病原体的一种可行方法。