Dose-dependent effect of nanosilver on the kinetics of development of clinically significant microorganisms in oral surgery practice: in vitro study

Surgical dentistry is associated with a high risk of infectious complications caused by pathogens such as S. aureus, S. constellatus, P. intermedia and C. albicans. Resistance of microorganisms to standard antimicrobial drugs and the formation of biofilms require the search for new effective agents. Nanargol, which has a broad spectrum of action, is of interest for use in the prevention and treatment of postoperative infections. The purpose of the study — to study the dose-dependent antimicrobial activity of antiseptic drug with nanosilver against model pathogens, assessing its effect on the growth kinetics of microorganism populations. Materials and methods. The study was conducted on clinical isolates of S. aureus, S. constellatus, P. intermedia and C. albicans using the automated culture system RTS-8. Growth phases (lag, logarithmic, stationary, dying off) and key points (α — maximum growth rate, β — maximum culture density) were assessed. The drug was used in dilutions of 1:5, 1:25 and 1:125. Results. Antiseptic drug with nanosilver demonstrated dose-dependent growth inhibition of all studied microorganisms. The highest efficiency was noted for C. albicans: a decrease in α and β points by 34.5% and 41.2%, respectively (p<0.05). In S. aureus, the lag phase increased by 2.5 times (p<0.05). For P. intermedia and S. constellatus, significant changes were observed only at high concentrations (1:5 and 1:25). Growth variability (IQR) decreased by 42.8% in C. albicans and by 34.2% in P. intermedia (p<0.05), indicating stabilization of growth kinetics. Conclusions. The dose-dependent inhibitory effect of the studied antiseptic based on silver nanoparticles is due to the pronounced suppression of the growth of all studied microorganisms (S. aureus, S. constellatus, P. intermedia, C. albicans), with the greatest effectiveness observed at maximum concentration (dilution 1:5). In C. albicans, there was a decrease in the key growth points α and β by 34.5% and 41.2%, respectively, and in S. aureus, an elongation of the lag phase by 2.5 times, which confirms the antimicrobial activity of the drug.