Activity of Copper and Silver oxide NPs in forming ainhibition zone in Streptococcus salivarius and Lactobacillus rhamnosus

Background and Aim : Human societies are still in difficulty encounter with human pathogens,despite advances in personal health and control of various diseases. One of these problems is toothdecay, which causes annoyingly high mortality and financial losses in human societies. In recentyears, nanotechnology has been able to make profound developments in the research andproduction of various products. Therefore, in this study antibacterial effects of Copper (Cu)nanoparticles and silver oxide (AgO) are investigated through various microbial tests (discs, wellsand cylinders diffusion Method) on two microorganisms of Streptococcus salivarius andLactobacillus rhamnosus, which act as primary colonizers in the formation of dental plaque.Methods : In the well diffusion Method, The bacterial suspension was prepared equaled ۰.۵McFarland. Wells were created and ۲۰ μl of various concentrations (۵۰۰, ۲۵۰۰, ۵۰۰۰, ۱۲۵۰۰,۲۵۰۰۰ ppm) of nanoparticles suspension were poured separately in them. In the disk diffusionmethod, was performed like Well diffusion, except that the disk was placed instead of creation thewells. In the cylinder diffusion method, was performed like Well diffusion, except that using sterilepins placed sterile cylinders on the plate, instead of creation the wells, and ۱۰۰ μl of variousconcentrations (۵۰, ۲۵۰, ۵۰۰, ۱۲۵۰, ۲۵۰۰ ppm) of nanoparticles suspension were poured separatelyon them. Sterile physiological saline was used for negative control. Incubated plates at ۳۷ °C for۲۴ h. Formation or non-formation of inhibition zone studied under light and reported.Results : Cu nanoparticles exhibited a more lethal effect than AgO nanoparticles in all three testsperformed in solid media (discs, wells and cylinders). In these tests, the inhibition zone ofLactobacillus rhamnosus was larger than the Streptococcus salivarius. It was also found that byincreasing the concentration of nanoparticles, their fatal rate increased significantly.Conclusion : Based on the data obtained in this test, copper nanoparticles were detected more fataland antibacterial than silver nanoparticles and Lactobacillus rhamnosus was more sensitive thanStreptococcus salivarius. It was also found that by increasing the concentration of nanoparticles,their fatal rate increased significantly. According to other studies carried out in this area, which allprove antibacterial properties of these nanoparticles at low concentrations, these nanoparticles canbe used as antibacterial agents in combination with mouthwashes and toothpastes in the market.

کلیدواژه ها:

Copper ، Silver oxide ، Streptococcus salivarius ، Lactobacillus rhamnosus ، Nanoparticle