Antimicrobial activity and chemical composition of essential oil and hydrosol extract of Nepeta nepetella subsp. amethystina (Poir.) Briq. from Algeria.

The essential oil and hydrosol extract of Nepeta nepetella subsp. amethystina, obtained by hydrodistillation and analysed by GC, GC–MS, 1H and 13C NMR, were evaluated for their antimicrobial activity using disks diffusion method and MICs against thirteen pathogenic microorganisms. The chemical analysis of essential oil and hydrosol extract allowed the identification of 34 and 12 constituents representing 96.77% and 80.07% of total oil and hydrosol extract, respectively. The two isomers 4a,7,7a-nepetalactone and 4a, 7, 7a-nepetalactone were found to be the major components in N. amethystina essential oil and hydrosol extract, , 7-nepetalactone and 4a,7a,7respectively. The two isomers 4a -nepetalactone were found to be the major components in N.7a amethystina essential oil and hydrosol extract. Candida albicans strains were the most sensitive microorganisms towards N. amethystina essential oil and hydrosol extract, which have the largest inhibition zones (˃30mm) and the lower MICs values (<1.25%). The anti-mold activity, carried out by the diffusion method, showed that N. amethystina essential oil has a very interesting activity against Aspergillus flavus and Cladosporium herbarium.

Antimicrobial activity of some essential oils against oral multidrug-resistant Enterococcus faecalis in both planktonic and biofilm state

Objective: To evaluate some essential oils in treatment of intractable oral infections, principally caused by biofilm of multidrug-resistant Enterococcus faecalis (E. faecalis), such as persistent endodontic infections in which their treatment exhibits a real challenge for dentists.Methods:were evaluated for antimicrobial activity against sensitive and resistant clinical strains of E. faecalis in both planktonic and biofilm state using two methods, disk diffusion and broth micro-dilution.Results:Studied essential oils showed a good antimicrobial activity and high ability in E. Ten chemically analyzed essential oils by gas chromatography-mass spectrometry faecalis biofilm eradication, whether for sensitive or multidrug-resistant strains, especially those of Origanum glandulosum and Thymbra capitata with interesting minimum inhibitory concentration, biofilm inhibitory concentration, and biofilm eradication concentration values which doesn’t exceed 0.063%, 0.75%, and 1.5%, respectively.Conclusions:Findings of this study indicate that essential oils extracted from aromatic plants can be used in treatment of intractable oral infections, especially caused by biofilm of multidrug-resistant E. faecalis.