Synergy between Pelargonium endlicherianum essential oil and conventional antibiotics againstNeisseria meningitidis and Haemophilus influenzae

2022 ◽  
Vol 146 ◽  
pp. 243-253
Author(s):  
Berrak Dumlupinar ◽  
Damla Damar Celik ◽  
Gokce Şeker Karatoprak ◽  
Ümran Soyoğul Gürer
Author(s):  
Shanjun Gao ◽  
Guangzhi Liu ◽  
Jianguo Li ◽  
Jing Chen ◽  
Lina Li ◽  
...  

Compared to mono-species biofilm, biofilms formed by cross-kingdom pathogens are more refractory to conventional antibiotics, thus complicating clinical treatment and causing significant morbidity. Lemongrass essential oil and its bioactive component citral were previously demonstrated to possess strong antimicrobial efficacy against pathogenic bacteria and fungi. However, their effects on polymicrobial biofilms remain to be determined. In this study, the efficacy of lemongrass (Cymbopogon flexuosus) essential oil and its bioactive part citral against dual-species biofilms formed by Staphylococcus aureus and Candida species was evaluated in vitro. Biofilm staining and viability test showed both lemongrass essential oil and citral were able to reduce biofilm biomass and cell viability of each species in the biofilm. Microscopic examinations showed these agents interfered with adhesive characteristics of each species and disrupted biofilm matrix through counteracting nucleic acids, proteins and carbohydrates in the biofilm. Moreover, transcriptional analyses indicated citral downregulated hyphal adhesins and virulent factors of Candida albicans, while also reducing expression of genes involved in quorum sensing, peptidoglycan and fatty acids biosynthesis of S. aureus. Taken together, our results demonstrate the potential of lemongrass essential oil and citral as promising agents against polymicrobial biofilms as well as the underlying mechanisms of their activity in this setting.


Antibiotics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1266
Author(s):  
Ângelo Luís ◽  
Fernanda Domingues

Increasing resistance of pathogens towards conventional antibiotics presents a major threat to public health because it reduces the effectiveness of antibiotic treatment. Mentha pulegium L., also known as pennyroyal, is an aromatic herb that belongs to the family Lamiaceae. Its essential oil has been traditionally used in medicine, aromatherapy, and cosmetics. The purpose of this work was to study the chemical composition of a pennyroyal essential oil and to evaluate their bioactivities, specifically, antioxidant, antimicrobial, anti-quorum sensing, and anti-inflammatory. A special focus was given to the antibacterial activity of the essential oil against Acinetobacter baumannii. The chemical composition of the essential oil was studied by GC-MS/GC-FID. The DPPH free radical scavenging assay and the β-carotene/linoleic acid system were used to evaluate the antioxidant properties. The antimicrobial and anti-quorum sensing activities were evaluated by disk diffusion assays and complemented with optical microscopy observations. The results showed that pulegone was the major compound (88.64%) of the pennyroyal essential oil. Regarding the antimicrobial activity, the action against Acinetobacter baumannii stands out, which, together with the capacity of the essential oil to inhibit the quorum sensing mechanisms, may suggest the use of the pennyroyal essential oil to further develop surface disinfectants for hospitals.


Author(s):  
Mozhgan MehriArdestani ◽  
Atousa Aliahmadi ◽  
Tayebeh Toliat ◽  
Abdolhossein Dalimi ◽  
Zohreh Momeni ◽  
...  

Vaginal infections are one of the major reasons women visit a gynecologist. Increased resistance to conventional antibiotics is one of the main factors mitigating the development of new antimicrobial agents, especially those of natural origin. In traditional Persian medicine, Trachyspermum ammi has been claimed to clear vagina from excessive discharge. Therefore, in this study, the antimicrobial activity of Ajwain essential oil was evaluated against some vaginal pathogens. The essential oil of ajwain was picked up and the minimum inhibitory and bactericidal concentrations (MIC and MBC) were revealed. The most frequently detected microorganisms involved in genital infections including Candida spp., Gardnerella vaginalis, Escherichia coli, Staphylococcus aureus, Streptococcus agalactiae and Lactobacillus acidophilus were considered. Evaluation of the essential oil of Trichomonas vaginalis was done by calculation of percent of growth inhibition. The essential oil showed a remarkable activity against the studied bacteria and fungi with MIC at a range of 0.0315 - 0.5 mg/ml and MBC at a range of 0.125 - 4 mg /ml. The highest inhibition and bactericidal activity was observed in S. agalactiae and G. vaginalis. 100% inhibition of T. vaginalis growth was shown at a concentration of 2000 μg/ml after 48 h by essential oil. The antimicrobial activity of the essential oil was more than that of thymol. Supposedly essential oil of Trachyspermum ammi fruit could inhibit vaginal pathogens growth .Further preclinical and clinical studies are required to confirm the efficacy of this natural agent in vaginitis.


2014 ◽  
Vol 61 ◽  
pp. 370-376 ◽  
Author(s):  
Mariam Fadli ◽  
Jean-Michel Bolla ◽  
Nour-Eddine Mezrioui ◽  
Jean-Marie Pagès ◽  
Lahcen Hassani

2018 ◽  
Vol 24 (3) ◽  
pp. 240-245
Author(s):  
Lamia Boudjedjou ◽  
Messaoud Ramdani ◽  
Azzeddine Zeraib ◽  
Tarek Benmeddour ◽  
Azzedine Fercha

Background: Over the past decade, most antibiotic research programs have focused on finding new compounds with antimicrobial activity. This study aims to investigate the chemical composition and antibacterial activity of the essential oil (EO) extracted from ripe berries of Algerian Juniperus thurifera var. aurasiaca. Methods: The chemical composition of J. thurifera EO extracted by hydrodistillation was analyzed by using the GC-MS technique. Antibacterial activity of EO alone and in combination with three conventional antibiotics was assessed by using disc diffusion method against four bacterial strains. Results: Thirty-five components were identified, representing ~87 % of the oil. The main components were m-mentha-6,8-diene (15.43 %), β-pinene (10.59 %), elemol (8.31 %) and terpinene-4-ol (7.44 %). The essential oil showed strong antibacterial activity against S. aureus and E. coli, but no activity against P. aeruginosa and B. subtilis. Synergistic effects were observed because of the combined application of EO with gentamicin against all strains tested, and with amoxicillin against B. subtilis. Furthermore, the combination of EO/cefazolin demonstrated an additive effect against B. subtilis. In contrast, the combination of EO with amoxicillin and céfazoline revealed antagonistic effects against S. aureus, E. coli, and P. aeruginosa. Conclusion: This is the first report on the chemical composition and antibacterial activity of Algerian juniper berries’ essential oil. The results indicate that the studied EO may be a promising source of antibacterial compounds that could be useful for pharmaceutical applications especially in combination with conventional antibiotics.


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