College of Applied Sciences, Samarra University discusses a master dissertation on the virulence factors of Streptococcus mutans isolated from dental caries and the effect of gold nanoparticles on them by the postgraduate student, Ms. Mays Yasser Younis.
The dissertation aimed at isolating and identify Streptococcus mutans from dental caries and root inflammation, perusing the bacterial resistance to certain antibiotics, as well as studying the inhibitory activity and effects of thyme plant extract, gold nanoparticles (AuNPs), and the effects of gold nanoparticles with thyme plant extract (Au-P.ENPs) on Streptococcus mutans at concentrations of 100, 50, 25, 12.5, and 6.25 µg/ml using the diffusion etch method.
The dissertation reviewed that 60 isolates out of a total of 150 samples belong to Streptococus Viridans bacteria, which constitutes 40%, while 90 isolates do not belong to Streptococus Viridans, i.e. they do not show growth on the medium (MSB), which constitutes 60%, also, the isolates isolated from dental caries showed complete resistance of 100% to the antibiotics Metronidazole and Cefotaxime, as well as the highest inhibition at a concentration of 100, as the inhibitory diameter was (14 mm) for the bacteria isolated from dental caries and (24 mm) for the bacteria isolated from the tooth root.
