*1Zatout, A., 1Djibaoui, R., 2Flamini, G., 2Ascrizzi, R., 3Benbrahim, C., 4Mazari, H. E., 5Benkredda, F., 6Mechaala, S., and 7,8Kassah-Laouar, A.
1Laboratory of Microbiology and Plant Biology, Department of Biological Sciences, Faculty of Natural Sciences and Life, University of Abdlhamid Ibn Badis, Mostaganem, Algeria
2Dipartimento di Farmacia, Via Bonanno 6, 56126 Pisa, Italy
3Laboratory of Microbiology Applied to the Agroalimentary Biomedical and the Environment, Department of Biology, Faculty of Natural Sciences and Life, University Abou BekrBelkaid, Tlemcen, Algeria
4 Geo-environment and Space Development (LGEDE), University of Mustapha Stambouli, Mascara, Algeria
5Laboratory of Applied Microbiology, University of Oran 1 Ahmed Ben Bella, Algeria
6Laboratory of Genetics, Biotechnology and Valorization of Bio-resources, Department of Natural Sciences and Life,
Faculty of Exact Sciences and Sciences of Nature and Life, Mohamed Khider University, Biskra, Algeria
7Central Laboratory of Medical Biology, Anti-Cancer Center, Batna, Algeria
8Faculty of Medicine, University of Batna 2, Batna, Algeria
*Correspondence to: asma.zatout@univ-mosta.dz
Abstract:
Background: The altitudinal and geographical variability of the Aurès mountains of Algeria favored the existence of some endemic and rare varieties of medicinal plants. The aim of the present work is to determine the chemical composition, antimicrobial and antibiofilm properties of the essential oils (EOs) from aerial parts of four medicinal plants from Aurès region of Algeria; Juniperus thurifera L., Juniperus oxycedrus L., Salvia officinalis L. and Thymus ciliatus ssp. munbyanus (Boiss. & Reut.) Batt. on coagulase negative staphylococci (CoNS) isolates.
Methodology: Extraction of EOs from the four plant materials was carried out by hydro-distillation, and the EO yield expressed in gram of the distillate per 100 grams of dry matter. The chemical composition of the EOs was analyzed by gas chromatography-mass spectrometry (GC-MS) method. In vitro antibacterial and antibiofilm activities of the EOs were evaluated against CoNS previously isolated at the Anti-Cancer Center of Batna, Algeria using the agar disc diffusion assay and biofilm inhibition study, respectively. Minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) of the EOs of S. officinalis L. and T. ciliatus ssp. munbyanus were determined by the dilution method.
Results: Twenty-seven and 41 compounds rich in monoterpene hydrocarbons were identified from J. oxycedrus and J. thurifera plants respectively, while 45 and 32 compounds, constituted mainly by oxygenated mono- terpenes, were identified from S. officinalis L. and T. ciliatus ssp. munbyanus, respectively. The EOs of T. ciliatus ssp. munbyanus showed the most inhibitory activity of all the four plants on CoNS isolates (n=66) with mean inhibition zone diameter of 24.99±6.29mm, and mean MIC and MBC values of 2.65±3.77mg/ml and 5.31±7.41mg/ml respectively, followed by S. officinalis L., with mean inhibition zone diameter of 13.38±
6.52mm, and mean MIC and MBC values of 27.53±28.2 mg/ml and 31.97±33.19 mg/ml respectively (p<0.0001 by one-way ANOVA). Also, percentage biofilm inhibition of CoNS isolates (n=59) was high for EOs of T. ciliatus ssp. munbyanus (65.63±10.71%) and S. officinalis L. (53.13±5.83%), although was significantly higher for T. ciliatus ssp. munbyanus compared to S. officinalis L. (p<0.0001, t=7.874).
Conclusion: Essential oils from T. ciliatus ssp. munbyanus and S. officinalis L. could represent an alternative to classical antibiotics against planktonic cells and biofilms of CoNS.
Keywords: coagulase-negative staphylococci; chemical composition; essential oils; antibacterial activity; antibiofilm activity
Received Mar 19, 2022; Revised Apr 15, 2022; Accepted Apr 16, 2022
Copyright 2022 AJCEM Open Access. This article is licensed and distributed under the terms of the Creative Commons Attrition 4.0 International License <a rel=”license” href=”//creativecommons.org/licenses/by/4.0/“, which permits unrestricted use, distribution and reproduction in any medium, provided credit is given to the original author(s) and the source. Editor-in-Chief: Prof. S. S. Taiwo
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