Preparation, Characterization of Selenium Nanoparticles from E.coli and Study its Effect on Pathogenic Bacteria

Bacterial infections might be regarded as one of the primary issues confronting the healthcare system at the moment. The development of nanoparticles offers an alternative to the usage of antibiotics. Sixty five isolates of Escherichia coli were isolated from various specimens, and used for the production of selenium nanoparticles at concentration 100 mM during 48 h, pH 8, agitation speed 160 rpm, and visualized by appearance of red color in the medium. Characterization employing Fourier transform infrared spectroscopy and UV-Vis spectroscopy showed absorption band formed at 266 nm, while, in X- Ray Diffractometer the Se-NPs peaks centered at 2θ of 27.605 , 32.092, 45.652, 56.815, 66.458 and 75.632, corresponded to the crystal planes of (100), (101), (012), (200),(022) and (210). Zeta potential demonstrate the colloidal dispersion's stability of Se-NPs with negative charge (-60mV), and Scanning Electron Microscopy showed spherically-shaped NPs with a size range between (46.71–71.91). Antimicrobial activity showed the highest inhibition zones to Klebsiella pneumoniae and Staphylococcus aureus (19.67 ± 0.58, 18.50 ± 0.87) mm respectively mm and against Escherichia coli was moderate inhibition (14.17 ±1.76). While the lowest zone of inhibition was observed against P. aeruginosa (12.00 ± 1.00) at 50 µl/ml respectively. The maximum antibiofilm activity of SeNPs was observed to be against S. aureus, P. aeruginosa, K. pneumoniae and E. coli MIC concentration were (89.34, 81.65, 79.81 and 80.27 ) % respectively, While at Sub MIC concentration were (80.81, 75.35 , 64.67 and 70.54) % respectively, So, It is an effective new antibacterial and antibiofilm agent that has applications.