title: Biogenic nanoparticles bearing antibacterial activity and their synergistic effect with broad spectrum antibiotics: Emerging strategy to combat drug resistant pathogens.
abstract: The present study emphasizes on synthesis of bimetallic silver-gold nanoparticles from cell free supernatant ofPseudomonas veroniistrain AS41G inhabitingAnnona squamosaL. The synthesized nanoparticles were characterized using hyphenated techniques with UV-Visible spectra ascertained absorbance peak between 400 and 800 nm. Possible interaction of biomolecules in mediating and stabilization of nanoparticles was depicted with Fourier transform infrared spectroscopy (FTIR). X-ray diffraction (XRD) displayed Bragg's peak conferring the 1 0 0, 1 1 1, 2 0 0, and 2 2 0 facets of the face centered cubic symmetry of nanoparticles suggesting that these nanoparticles were crystalline in nature. Size and shape of the nanoparticles were determined using Transmission electron microscopy (TEM) microgram with size ranging from 5 to 50 nm forming myriad shapes. Antibacterial activity of nanoparticles against significant human pathogens was conferred with well diffusion assay and its synergistic effect with standard antibiotics revealed 87.5% fold increased activity with antibiotic "bacitracin" against bacitracin resistant strainsBacillus subtilis,Escherichia coliandKlebsiella pneumoniaefollowed by kanamycin with 18.5%, gentamicin with 11.15%, streptomycin with 10%, erythromycin with 9.7% and chloramphenicol with 9.4%. Thus the study concludes with biogenic and ecofriendly route for synthesizing nanoparticles with antibacterial activity against drug resistant pathogens and attributes growing interest on endophytes as an emerging source for synthesis of nanoparticles.
authors.affiliation: Bionanotechnological Research Laboratory, Department of Studies in Microbiology, University of Mysore, Manasagangotri, Mysore 570 006, India.
authors.forename: Syed
authors.initials: S
authors.lastname: Baker
authors.affiliation: Bionanotechnological Research Laboratory, Department of Studies in Microbiology, University of Mysore, Manasagangotri, Mysore 570 006, India.
authors.forename: Azmath
authors.initials: A
authors.lastname: Pasha
authors.affiliation: Bionanotechnological Research Laboratory, Department of Studies in Microbiology, University of Mysore, Manasagangotri, Mysore 570 006, India; Department of Plant Pathology, University of Georgia, Athens 30602, USA.
authors.forename: Sreedharamurthy
authors.initials: S
authors.lastname: Satish
keywords: Bimetallic silver–gold nanoparticles; Biogenic; Broad spectrum antibiotics; Pseudomonas veronii AS41G; Synergistic activity