RÉSUMÉ
Pseudomonas aeruginosa is a pathogenic and nosocomial bacterium responsible for serious healthcare-associated infections mainly for its resistance to antibiotics. Against this problem researches for new active substances must be continued to overcome nosocomial infections caused by P. aeruginosa. Essential oils extracted from medicinal plants are a good alternative thanks to their proved antimicrobial activities. This study aims to evaluate the antibacterial activity of five essential oils obtained from plants that grow naturally in western Algeria against antibiotic-resistant P. aeruginosa strains. The studied essential oils, obtained by hydrodistillation, were analysed for the determination of their composition using GC-MS. The antibacterial activity of the studied essential oils was evaluated by disk diffusion and broth microdilution methods against fourteen P. aeruginosa strains, of which thirteen have been isolated from clinical sources and one reference strain. The obtained results show that Cistus munbyi and Thymus lanceolatus essential oils possess a good activity against antibiotic-resistant PP. aeruginosa strains. While Origanum glandulosum, Ammoides verticillata, and Thymbra capitata were less active respectively. Thus, C. munbyi and T. lanceolatus essential oils can be considered as good alternatives treatment against nosocomial infections caused by P. aeruginosa
RÉSUMÉ
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,7respectively. 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.
RÉSUMÉ
Urinary tract infections (UTIs) are ones of the most common nosocomial infections worldwide. Lesions which are mainly caused by microorganisms that inhabiting in hospitals, known and characterized by their both resistance against antibiotics and high ability of biofilms formation. In this study, we have evaluated the effect of three essential oils, which are Cinnamomum cassia, Coriandrum sativum and Ziziphora hispanica, against bacterial species most responsible for UTIs. A total of 18 bacterial strains were tested, which varies between reference strains and clinical multidrug resistant. Cassia oil was the most antimicrobial active against all strains, with interesting MICs values which doesn’t exceed 5 mg/ml. The finding of this study indicate that essential oil appears as an excellent solution for treatment of nosocomial UTIs, especially against failure problems seen in care services, which are over common in the last years.
RÉSUMÉ
The objective of this work was to examine the phytochemicals present in different aqueous and organic extracts from different organs of Daucus crinitus Desf. and to evaluate their antimicrobial activity. Phytochemical screening was done to characterize the secondary metabolites in various solvent extracts, and antimicrobial activity was evaluated by agar disk diffusion and broth microdilution to determine inhibition zone diameters and MICs. A remarkable antimicrobial effect was observed in organic extracts of stems and seeds (MIC = 0.31-0.83 mg/ml on S. aureus, B. cereus, and C. albicans) containing many phytochemical families such as coumarins, flavonoids, reducing sugars, steroids, tannins, and terpenes. Daucus crinitus may be a good source of bioactive molecules endowed with antimicrobial activity.