The in vitro antimicrobial activity of highly dispersed silica and polyhexamethylene guanidine hydrochloride composite for treating local infections

Abstract

Antimicrobial drug resistance (ADR) is an urgent global problem for all countries; it has a negative effect on the treatment outcome of patients. The problem can be solved by creating and introducing new antimicrobial compounds and complex drugs. Development of the combined antimicrobial agent which would show the expressed antimicrobial action and sorption properties remains relevant. Polyhexamethylenguanidine hydrochloride (PHMG-HC), being a highmolecular cationic surfactant of the guanidine group, was chosen as an antimicrobial component. Aim. To determine the antimicrobial activity of highly dispersed silica (HDS), a composite (code name CMU-211) of HDS and PHMG-HC, and PHMG-HC polymer solution. Materials and methods. 5% suspension of HDS modified by PHMG-HC polymer, 5 % suspension of HDS and 20 % aqueous solution of polyhexamethyleneguanidine hydrochloride were used in the work. The antimicrobial activity of substances was studied using test-strains of such microorganisms as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella enterica, Klebsiella pneumoniae, and Candida albicans. Results. The composite HDS/PHMG-HC has been shown to have a high activity against C. albicans and S. aureus with the minimum inhibitory concentration (MIC) of ~10 μg/mL (calculated with reference to HDS/PHMG-HC), as well as the marked effect against E. coli (MIC of ~20 μg/mL), S. enterica (MIC of MIC ~40 μg/mL) and P. aeruginosa (MIC ~40 μg/mL). The relatively low activity of CMU-211 was reported against K. pneumoniae (MIC ~ 80 μg/mL). The activity of the composite HDS/PHMG-HC was similar to those of PHMG-HC. Conclusions. The composite HDS/PHMG-HC developed exhibits the marked antibacterial activity against gram-positive, gram-negative microorganisms, as well as C. albicans.