Determination of Minimum Inhibitory Concentration (MIC)and Minimum bactericidal Concentration (MBC) of Copper (Cu) andSilver oxide (AgO) Nanoparticles against Streptococcus salivarius

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 Silver oxide (AgO)and Copper (Cu) nanoparticles are investigated through various microbial tests on Streptococcussalivarius, which act as primary colonizers in the formation of dental plaque.Methods : In each tube ۱ ml bacterial suspension and ۱ ml Cu and AgO nanoparticles suspensionadded relatively. In this case, the final volume in each well was equal to ۲ ml and the finalconcentration of the bacterium was equal to ۵ ×۱۰۵. Incubated at ۳۷ °C for ۱۸ h. To determine theminimum bactericidal concentration (MBC), ۱۰۰ μl of the tubes were taken and streaked on plateswith a Muller Hinton Agar. Then they examined for bacterial growth and colony formation. Forthe study of Effect of nanoparticles in ۲۴-hour culture, is done in the same way as above. Recapthe tubes and incubated at ۳۷ °C for ۲۴ h. Result observed spectrophotometer at ۶۰۰ nmwavelength.Results : The minimum inhibitory concentration (MIC) of Copper nanoparticles for Streptococcussalivarius was ۳۱۲.۵ ppm, and the Minimum bactericidal concentration (MBC) was obtained ۶۲۵ppm, though for the Silver oxide nanoparticle, the MIC was ۶۲۵ ppm and MBC was ۱۲۵۰ ppm.The growth of bacteria in the presence of nanoparticles has declined after ۲۴-hour incubation.Conclusion : Based on the data obtained in this test, Copper nanoparticles were detected morefatal and antibacterial than Silver oxide nanoparticles. It was also found that by increasing theconcentration of nanoparticles, their fatal rate increased significantly. According to other studiescarried out in this area, which all prove antibacterial properties of these nanoparticles at lowconcentrations, these nanoparticles can be used as antibacterial agents in combination withmouthwashes and toothpastes in the market.

کلیدواژه ها:

Copper ، Silver oxide ، Streptococcus salivarius ، Nanoparticle