Antibacterial potential of silver nanoparticle synthesized by marine actinomycetes in reference with standard antibiotics against hospital acquired infectious pathogens

Multi resistance to antibiotics is a serious and disseminated clinical problem, common to several new compounds that block the resistance mechanism. The present study aimed at the comparative study of silver nanoparticles synthesized through actinomycetes and their antimicrobial metabolites with standard antibiotic. Marine actinomycetes collected from Gulf mannar costal region, Kayalpatnam, located at Tuticorin district, Tamil nadu, India. Totally, five actinomycetes were isolated and identified based on their spore formation and biochemical studies. Three isolates belonged to the genera of  Streptomyces sp and two were Micromonospora sp. Streptomyces sp KPMS3 showed potent antibacterial activity against Gram negative pathogens. Gram positive isolates are sensitive to  Micromonospora sp (KPMM2). Among the five isolates, isolate Micromonospora sp (KPMM2) was found to be an effective silver nanoparticle synthesizer. The obtained silver nanoparticles were characterized using UV-Vis spectroscopy, FTIR and TEM. The morphology of nanoparticle is found to be spherical and an average size of ranges between 38 to 52 nm. The antimicrobial activities of silver ion against test pathogens were found to be superior to cephalosporin antibiotic. The in vitro hemolytic assessment of silver nanoparticles were found to be non-hemolytic at maximum of 20 μg/ml. It was found that smaller silver nanoparticles synthesized by microbial route had a greater antibacterial activity and less hemolytic in nature. Keywords: ESBL, cefotaxime, drug resistant and hemolysis