Avaliação do potencial antibacteriano de scaffolds de quitosana incorporados aos óleos essenciais de orégano e tomilho contra cepas de Enterococcus faecalis e Escherichia coli.

Abstract

Changes in the ecology of bacteria that make up the oral biofilm, as well as in the population proportion of this microbiota, promote dysbiosis and favor the emergence of simple or even complex pathological states. Polymicrobial dysbiotic biofilms may be tolerant to the immune responses of the host organism and to antimicrobial treatments, allowing the persistence of some bacteria, such as Enterococcus faecalis and Escherichia coli, which have a potential relationship with infections in oral wounds, periodontitis, peri-implantitis and infections in the root canal system. Therefore, the search for alternative substances to control these resistant microorganisms has aroused great scientific interest, expanding the use of biomaterials and herbal medicines in health. The present work aimed to evaluate the antibacterial potential of chitosan-based scaffolds incorporated with essential oils (EOs) of Origanum vulgare L. and Thymus vulgaris L. against strains of Enterococcus faecalis and Escherichia coli. The antibacterial potential was evaluated by reading the strangulation halos formed around chitosan-based scaffolds incorporated with thyme EO, oregano EO and thyme and oregano EO against strains of Enterococcus faecalis (ATCC-29212) and Escherichia coli (CCCD- E003), using the well agar diffusion methodology. For this, Mueller Hinton Agar was used as a culture medium in Petri dishes, and holes of 6 mm in diameter were formed with the aid of a mold, originating the wells. The plates were inoculated on the surface by the microorganism using a swab, then they were incubated in a bacteriological oven at 37 ºC for 24 hours. Scaffolds, in the form of discotheques, were aseptically deposited in the wells of inoculated media, which were incubated at 37 ºC for 24 hours. After incubation, the plates were observed for the homogeneity of bacterial growth, and the measurement of the diameter of the inhibitory halo was carried out, with the aid of a millimeter ruler, in cases where inhibition of bacterial growth was verified. Tests were performed in duplicate and results correspond to mean values. It was observed that the association of chitosan with the EOs of Origanum vulgare L. and Thymus vulgaris L. has antibacterial activity against strains of Enterococcus faecalis and Escherichia coli. For the scaffolds incorporated with the EO of Origanum vulgare L., the formation of inhibition halos of 14 and 16 mm was obtained for the strains of Enterococcus faecalis and Escherichia coli, respectively. For the scaffolds incorporated with the EO of Thymus vulgaris L., the formation of inhibition halos of 14 and 16 mm was also obtained for the strains of Enterococcus faecalis and Escherichia coli, respectively. However, for those scaffolds incorporated with the association between the EOs of Origanum vulgare L. and Thymus vulgaris L., the formation of inhibition halos of 12 and 16 mm was obtained for the strains of Enterococcus faecalis and Escherichia coli, respectively. The association of chitosan with the EOs of Origanum vulgare L. and Thymus vulgaris L. has antibacterial activity, acting as a bactericide against the tested strains of Enterococcus faecalis and Escherichia coli.