In recent years, medical science has turned to a variety of new products and technologies to halt the spread of infections. The most effective and promising antimicrobial agents being embraced by modern medical science today is silver, which is also one of the oldest. In 1940s breakthroughs in antibiotics such as penicillin, actinomycin and streptomycin, medical science began to shift its attention away from preventative compounds such as antimicrobial silver and focused instead on antibiotic treatments. With increasing drug-resistance and growing concern regarding the over-prescribing of antibiotics, there has been a resurgent interest in the use of antimicrobial silver. Unlike antibiotics, silver appears to be immune to resistance. Thus, the conjugation of antibiotic with AgNP (Silver nanoparticles) would prevent development of resistance by microbes and enhance the antimicrobial property of the antibiotic. This study is based on the synergistic effect of Cephalexin antibiotic with AgNP. The nanoparticles were evaluated for their increased antimicrobial activities with Cephalexin antibiotic against E.coli and S. aureus. The antibacterial activity of Cephalexin was increased in the presence of AgNPs against test strains. The results showed that the combination of antibiotics with AgNPs have better antimicrobial effects.
The present study was carried out to assess the antibacterial activity of bacteria associated with Polychaetes. Polychaetes were collected from the coastal environment and the bacterial communities associated with the surfaces were isolated using traditional culture method. Four biofilm bacteria (Galionella sp., Alteromonas sp., S.aureus, Klebsiella sp.) isolated from the marine water was used as target organism for screening. Three surface associated bacteria were isolated from the surface. The EPS of the three surface associated bacteria were isolated and tested for their antimicrobial activity. The results showed that higher activity against Alteromonas sp. The bioactive compounds were separated by thin layer chromatography. The results showed higher activity against Alteromonas sp. Based on the study, it can be concluded that bacteria associated with Polychaetes would serve as a potential source for the isolation of bioactive compounds.

