Antibacterial Effect of Zink Oxide Nanoparticles on Drug Resistant Viridans Group Streptococci Isolated from Dental Samples of Pupils

Dental caries is one of the most common infections in children which is mainly caused by the bacteria living in the mouth. Viridans group Streptococci are the most common microbes which have a very close relationship with this infection. The aim of the present study is to review the antimicrobial effect of Zink oxide nanoparticles on the growth of drug resistant viridans Streptococci isolated from pupils.
Material and This cross-sectional study has been conducted randomly on 120 elementary school pupils. After sampling, biochemical tests were carried out to identify Streptococcos viridans strains. The susceptibility to various antibiotics was evaluated using disk diffusion method and the antibacterial properties of Zink oxide nanoparticles were assessed through agar well diffusion method. Data analysis was performed using chi-square and one-way variance tests.
In this study, the frequency of viridans group Streptococci in dental samples of children was reported to be 66.7%. The most antibacterial resistance was to Vancomycin with the frequency of 81%. Also, 81% of the isolated streptococci were susceptible to Amoxicillin. The next frequent susceptibilities were seen to Cefotaxime with 56%, Erythromycin with 27%, Vancomycin with 19% and Clindamycin with 11%. In the well diffusion method, 72% of the strains resistant to Erythromycin and Clindamycin, 92% of the strains resistant to Cefotaxime and Amoxicillin, and 78% of the strains resistant to Vancomycin were destroyed in the concentration of 50 mg/ml of the Zink oxide nanoparticles, and the rest were destroyed in concentration of 100 mg/ml of these nanoparticles.
Zink oxide nanoparticles used in this study showed a very high antimicrobial effect against all drug resistant viridansgroup Streptococci, and the bactericidal effects were increased upon increasing the concentration of nanoparticles.