Composition and antimicrobial activity of Cistus munbyi essential oil: an endemic plant from Algeria

The chemical composition and antimicrobial potential of Cistus munbyi essential oil were studied for the first time. GC and GC–MS analysis revealed 48 compounds representing 96.98% of the oil. Terpinen-4-ol(23.75%), meta-Cymene(17.30%), and Sabinene(12.38%)were the major constituents. Antimicrobial activity was evaluated against nine pathogens using the disc diffusion and broth micro-dilution methods. Results show that C.munbyi essential oil possesses strong antimicrobial activity against all strains, regardless if Gram-positive or Gramnegative bacteria, or yeast, with MICs values not exceeding10(mg/ml). In addition to its efficacy, C. munbyi essential oil has an unusual antimicrobial potency which is attributed to its specific chemical composition. Thus, findings presented here suggest that endemic C. munbyi contains a very interesting essential oil that may be valuable in several areas.

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

Objective:To evaluate some essential oils in treatment of intractable oral infections,principally caused by hiofilm of multidrug-resistant Enterococcus faecalit(E.faecalis),such as persistent endodontic infections in which their treatment exhibits a real challenge for dentists.Methods:Ten chemically analyzed essential oils by gas chromatography-mass spectrometry were evaluated for antimicrobial activity against sensitive and resistant clinical strains of E.faecalit in both planktonic and hiofilm state using two methods,disk diffusion and broth microdilution.Results:Studied essential oils showed a good antimicrobial activity and high ability in E.faecalit 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 concent ration 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 multidrugresistant E.faecalis.

Identification and preliminary characterization of non-polyene antibiotics secreted by new strain of actinomycete isolated from sebkha of Kenadsa, Algeria

Objective: To study the antimicrobial activity of actinomycetes isolated from sabkha of Kenadsa and identification of the isolate interesting. Methods: Eighteen strains were isolated, using four culture media from sebkha of Kenadsa(Bechar, Southwestern Algeria). Screening of antimicrobial activity consisted of two steps: in primary screening, antibacterial activity was determined by using the agar plug method against test strains; in secondary screening, better isolate which showed a good activity in the first screening was selected to extract antimicrobial substances. The antimicrobial activities of extracts were evaluated by using Kirby-Bauer disc diffusion method. Partial characterization of antimicrobial products was performed on the basis of chemical revelations, UV-vis spectrometry and infrared spectroscopy. The identification of isolate interesting was performed through morphological, chemical, biochemical and physiological characteristics. Results: All isolates showed antimicrobial activity against at least one microorganism test. One isolate, LAM143 cG 3, was selected for its broad spectrum and high antimicrobial activity. The isolate LAM143 c G3 was identified as Spirillospora sp. The comparison between the species of this genus(Spirillospora rubra and Spirillospora albida) and our isolate indicated the existence of several physiological and biochemical differences which led us to suppose that this was a new member of this genus. Primary characterization of antimicrobial substances produced by the isolate LAM143 c G3 indicated the presence of amines and phenols. The UV–vis spectrum suggested a non-polyenic nature of substances secreted by our isolate, while infrared confirmed the presence of amine groups.Conclusions: The result of the present study revealed that sebkha of Kenadsa was rich in rare actinomycetes, that secreted interesting antimicrobial substance.

Antimicrobial activity of Rosmarinus eriocalyx essential oil and polyphenols:An endemic medicinal plant from Algeria

Objective:To evaluate the antimicrobial potency of Rosmarinus eriocalyx(R.eriocalyx)essential oil and total polyphenols against pathogenic microorganisms.Methods:Antimicrobial activity of R.eriocalyx extracts was assessed by disc diffusion method and minimum inhibitory concentrations determination.Essential oil obtained from endemic rosemary by hydrodistillation was analysed by gas chromatograph/retention index and gas chromatograph-mass spectrometer.Results:An interesting antimicrobial activity was shown by R.eriocalyx extracts.Polyphenols,constituted mainly by flavonoids,were the most effective extract with very low minimum inhibitory concentrations values,ranged between 0.06 and 8.00 mg/mL,while essential oil was less efficient.It should be noted that antimicrobial activities of both R.eriocalyx extracts were more directed against fungi and Gram-positive bacteria than Gram-negative ones,in which Staphylococcus aureus,Enterococcus faecalis,and Candida albicans were the most sensitive strains.Concerning chemical composition of R.eriocalyx essential oil,camphor(37.8%),1,8-cineole(17.4%),camphene(13.3%),and α-pinene(10.9%)were the major compounds.Conclusions:The findings of the present study indicate that R.eriocalyx extracts possess significant bactericidal and fungicidal activities.Because of its richness in essential oil,and especially flavonoids,R.eriocalyx may be a source for effective and safe antimicrobial agents.