RESUMO
Metal nanoparticle synthesis is an interesting area in nanotechnology due to their remarkable optical, magnetic, electrical, catalytic and biomedical properties, but there needs to develop clean, non-toxic and environmental friendly methods for the synthesis and assembly of nanoparticles. Biological agents in the form of microbes have emerged up as efficient candidates for nanoparticle synthesis due to their extreme versatility to synthesize diverse nanoparticles with varying size and shape. In the present study, an eco favorable method for the biosynthesis of silver nanoparticles using marine bacterial isolate has been attempted. Very interestingly, molecular identification proved it as a strain of Ochrobactrum anhtropi. In addition, the isolate was found to have the potential to form silver nanoparticles intracellularly at room temperature within 24 h. The biosynthesized silver nanoparticles were characterized by UV-Vis spectroscopy, transmission electron microscope (TEM) and scanning electron microscope (SEM). The UV-visible spectrum of the aqueous medium containing silver nanoparticles showed a peak at 450 nm corresponding to the plasmon absorbance of silver nanoparticles. The SEM and TEM micrographs revealed that the synthesized silver nanoparticles were spherical in shape with a size range from 38 nm - 85 nm. The silver nanoparticles synthesized by the isolate were also used to explore its antibacterial potential against pathogens like Salmonella Typhi, Salmonella Paratyphi, Vibrio cholerae and Staphylococcus aureus.
Assuntos
Antibacterianos/farmacologia , Nanopartículas/metabolismo , Ochrobactrum/metabolismo , Prata/farmacologia , Antibacterianos/metabolismo , Organismos Aquáticos/classificação , Organismos Aquáticos/genética , Organismos Aquáticos/isolamento & purificação , Organismos Aquáticos/metabolismo , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Bactérias Gram-Negativas/efeitos dos fármacos , Microscopia Eletrônica , Nanopartículas/química , Nanopartículas/ultraestrutura , Ochrobactrum/classificação , Ochrobactrum/genética , Ochrobactrum/isolamento & purificação , Filogenia , /genética , Análise de Sequência de DNA , Análise Espectral , Prata/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Temperatura , Fatores de TempoRESUMO
Objective: The study was undertaken to investigate the genomic and phenotypic relationship among E.faecium strains isolated from chicken and clinical sources. Methods: Enterococci were isolated and identified by conventional biochemical methods and the antibiotic susceptibility was determined by disk diffusion methods. Phenotypes and genotypes of vancomycin resistance were detected by E tests and PCR amplification techniques respectively. Genotyping of the vancomycin resistant E.faecium from two sources were done by RAPD typing. Results: The Vancomycin resistant E.faecium identified was selected for this comparative study. Among the VREF from two sources minor biochemical difference with regards to raffinose fermentation and haemolytic properties was observed. The RAPD tests using random primers also showed polymorphism. Conclusion: The results of the study showed that the strains from two different sources were not identical.