Exploiting the antimicrobial potential of an invasive aquatic weed Eichhornia crassipes mediated silver nanoparticles on multi drug resistant bacteria

Abstract

Resistance against commonly used antibiotics is an emerging global threat, mostly due to the evolution of multi-drug-resistant bacterial strains. This necessitates the search for anti-bacterial remedies that are cheaper, reliable, and easier to synthesize.  Green synthesized silver nanoparticles are widely employed as an antibacterial agent due to their unique physicochemical properties and considered as eco-friendly. In this study, we synthesized silver nanoparticles (AgNPs) using the aqueous extract from Eichhornia crassipes (EC) leaves. EC is an invasive aquatic weed which causes a decrease in oxygen levels in freshwater environments thereby contributing to eutrophication. The synthesized EC-AgNPs were characterized for their size, morphology, surface charge, crystalline nature using various techniques. Bacteria used for this study, viz; E. coli, K. pneumoniae, and S. aureus, P. mirabilis were characterized for their antibiotic resistance and were found to be to be multidrug resistant (MRD) and (extended spectrum beta-lactamase) ESBL producers. P. aeruginosa was characterized for its biofilm formation ability. The antibacterial ability of the EC-AgNPs at various concentrations was tested on these MRD pathogens by disc diffusion assay and minimum inhibitory concentration was determined. Results showed zone of inhibition even at very low concentrations indicating that the EC-AgNPs can be used as a potential antibacterial agent against MRD pathogens. The antibiofilm activity of EC-AgNPs was demonstrated in P. aeruginosa by crystal violet assay. The study emphasizes on the using aquatic weeds like E. crassipes for medical and pharmaceutical purposes so that they can be efficiently removed from environment and put to beneficial use.