| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1277-2 | ||||
Resumo:The advent of antimicrobial drugs has optimized treatments in the healthcare field; however, the emergence of drug-resistant bacteria has intensified the search for new antibacterial agents in nature. Ginger (Zingiber officinale), belonging to the Zingiberaceae family, has been reported in the literature for its antimicrobial and antioxidant activity. In light of this, the objective of this research was to evaluate the in vitro antibacterial and antibiofilm potential of two essential oils from Zingiber officinale (EO1 and EO2) against gram-positive bacteria of the Staphylococcus genus. EO1 was obtained commercially, and EO2 was extracted from ginger rhizomes sold in the city of Sobral-CE by hydrodistillation. Antibacterial activity was evaluated against the strains S. aureus (ATCC 6538) and S. epidermidis (ATCC 112238) using the agar disk diffusion method, Minimum Inhibitory Concentration (MIC) determination by the microdilution plate method, Minimum Bactericidal Concentration (MBC), growth curve, and biofilm assay using the Crystal Violet method (CV). EO1 showed antibacterial activity observed by the diameter of the inhibition zone (DIZ) only against S. aureus with a DIZ of 10.7±0.6 mm. EO2 exhibited activity against both S. aureus and S. epidermidis with DIZ of 11.3±0.6 and 16±1.0 mm, respectively. To determine the MIC of the essential oils, both were prepared in concentrations ranging from 8 to 0.12 mg/mL. The MIC and MBC of EO1 for S. aureus were 4 mg/mL and 8 mg/mL, respectively. Meanwhile, EO2 had MIC values of 2 mg/mL for both S. aureus and S. epidermidis. The MBC of EO2 was also 4 mg/mL for both strains. At subinhibitory concentrations (MIC/2 and MIC/4), the essential oils directly interfered with the bacterial growth kinetics, delaying the lag phase, and reducing bacterial growth in the log phase, as observed from optical densities compared to the control group (untreated cells). Regarding biofilm activity, both oils showed inhibition effects on biofilm formation for S. aureus. EO1 at concentrations of MBC, MIC, and MIC/2 reduced biofilm formation by 98.1%, 95.1%, and 71.9%, respectively. EO2 at MBC and MIC concentrations reduced biofilm formation by 100%, and at MIC/2 concentration, it reduced it by 58%. Under the cultivation conditions applied in this study, the S. epidermidis strain did not form a biofilm, making it impossible to measure the antibiofilm activity of ginger oils (EO1 and EO2) against this strain. Based on the in vitro results, EO1 and EO2 have biotechnological potential against S. aureus and S. epidermidis in planktonic form and antibiofilm activity against S. aureus. They can be considered as an alternative for the treatment of infections caused by gram-positive bacteria of the Staphylococcus genus. Palavras-chave: Antibacterial agents, Antibiofilm activity, Drug resistance, Ginger, Volatile oils Agência de fomento:Cearense Foundation for Scientific and Technological Development (FUNCAP) | |||||