RESUMEN
The present study describes the synthesis of silver and zinc oxide nanobactericides from the phytogenic source Bupleurum aureum. The synthesized nanobactericides were characterized and evaluated for bio-functionalization onto bacterial cellulose membrane which was synthesized by Komagataeibacterxylinus B-12068 culture strain. The synthesis of nanobacterides were initially confirmed using UV-Visible spectroscopy which indicated localized surface resonance (LSPR) peaks at 415â¯nm for silver nanobactericides and 280â¯nm for zinc nanobactericides. The nature of the capping agent for synthesized nanobactericides was predicted using FTIR which confirmed the presence of functional moieties. XRD analysis revealed their crystalline nature while morphological characteristics were studied using TEM which confirmed the polydispersity of nanobactericides with the average size in the range of 20-25â¯nm. The nanobactericides were tested for their antimicrobial activity against seven multi-drug resistant pathogens which were clinically isolated from patients suffering from a myriad of microbial infections. The tested pathogens had antimicrobial resistance to ten different antibiotics and have been reported to be the major cause of nosocomial infections. The nanobactericides displayed significant activity against the test pathogens. Silver nanobactericides showed the highest activity against Escherichia coli strain 55 with a 24â¯mm zone of inhibition while zinc oxide nanobactericides displayed the highest activity against methicillin-resistant Staphylococcus aureus (MRSA) with a 20â¯mm inhibition zone. The bio- functionalized cellulose films (BCF) were characterized using SEM along with physicochemical analysis. The BCF's were evaluated for antibacterial activity against test pathogens which resulted in marked antimicrobial potential against multi-drug resistant bacteria and therefore has the potential to be utilized as an efficient alternative to counter drug resistant pathogens.
Asunto(s)
Antibacterianos/farmacología , Bupleurum/metabolismo , Nanopartículas del Metal/toxicidad , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Plata/farmacología , Óxido de Zinc/farmacología , Antibacterianos/biosíntesis , Antibacterianos/química , Celulosa/química , Farmacorresistencia Bacteriana Múltiple , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Nanopartículas del Metal/química , Staphylococcus aureus Resistente a Meticilina/crecimiento & desarrollo , Pruebas de Sensibilidad Microbiana , Tamaño de la Partícula , Plata/química , Plata/metabolismo , Óxido de Zinc/química , Óxido de Zinc/metabolismoRESUMEN
Salmonella is one of the most dangerous and common food-borne pathogens. The overuse of antibiotics for disease prevention has led to the development of multidrug resistant Salmonella. Now, more than ever, there is a need for new antimicrobial drugs to combat these resistant bacteria. Aptamers have grown in popularity since their discovery, and their properties make them attractive candidates for therapeutic use. In this work, we describe the selection of highly specific DNA aptamers to S. enteritidis and S. typhimurium. To evolve species-specific aptamers, twelve rounds of selection to live S. enteritidis and S. typhimurium were performed, alternating with a negative selection against a mixture of related pathogens. Studies have shown that synthetic pools combined from individual aptamers have the capacity to inhibit growth of S. enteritidis and S. typhimurium in bacterial cultures; this was the result of a decrease in their membrane potential.