Biogenic Synthesis of Silver Nanoparticles Using Saraca indica Leaf Extract and Evaluation of Their Antibacterial Activity

The present study reports an unprecedented biogenic method for the synthesis of silver nanoparticles (AgNPs) using leaf extract of Saraca indica and characterized their antibacterial activity. We have also focused on the biosynthesis mechanism of AgNPs. Plant leaf extract has water soluble organic materials which help in the reduction of silver ions and stabilization of AgNPs. Aqueous solution of silver nitrate was treated with leaf extract of Saraca indica for the formation of AgNPs. The surface plasmon resonance was occurred at 412 nm. The size distribution profile of synthesized AgNPs was analysed by Dynamic Light Scattering (DLS). Transmission Electron Microscopy (TEM) has been done for the measurement of particle size and their morphology. The role of phytochemicals in the reduction of silver ions and defining the framework in which AgNPs are covered and provide steadiness can be determined through Fourier Transform Infrared Spectroscopy (FTIR). TEM micrograph reveals that the size of AgNPs was obtained in the range of 13-50 nm with spherical morphology. X-ray Diffraction (XRD) pattern of the AgNPs exhibited 2θ values corresponding to the silver nanocrystals. Furthermore, the antibacterial activity of synthesized AgNPs against E. coli DH5α was investigated by growth curve and inhibition zone analysis. It was observed that the 20 μg/ml concentration of biogenic AgNPs recorded as minimal inhibitory concentration (MIC) against E. coli DH5α

ANTIMICROBIAL EFFICACY OF ESSENTIAL OILS OF SELECTED PLANTS AND VACCINE DESIGN AGAINST mecA PROTEIN OF METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS

Objective- Emergence of Multi Drug Resistance indicates a dire to understand the bacterial involvement in infections and find out new alternative approaches in its therapeutics and prevention. The present study was undertaken to study the antimicrobial resistance patterns of S. aureus isolated from various samples collected from Hospitals of Gwalior. During the present study an effort was made to find out the information about mecA protein of Staphylococcus and their conserved regions were analyzed in order to assess their antigenic potential.Methods- In the present study, a total of 872 samples were collected and processed for MRSA screening. Conventional methods were used for the isolation and identification of bacteria. Thereafter, antibacterial property of 20 various drugs  as well as aromatic compounds of 18 herbal plants was performed against multiple resistant Staphylococcus aureus (MRSA) isolates according to the guidelines of National Committee for Clinical Laboratory Standards (NCCLS). In silico prediction of vaccine candidates in mecA through bioinformatics approach was also performed.Results-The study revealed that drug resistance pattern of MRSA isolates is increasing. But the major concern is the development of resistance against Vancomycin which is thought be the most effective drug against Staphylococcus. In comparison to antibiotics, essential oils showed very good activity against the test bacteria with few exceptions.Conclusion- The essential oils of Clove and Cinnamon were found to be more active against the test organism. We predicted multi-epitope peptide which was having very good potential to induce B cell response and a very good candidate for binding to MHC II molecule and thus can act as a suitable vaccine target against S. aureus.Keywords: Multidrug Resistance, essential oils, in silico, multi-epitope peptide