Premium
Activity of Six Essential Oils Extracted from Tunisian Plants against Legionella pneumophila
Author(s) -
Chaftar Naouel,
Girardot Marion,
Quellard Nathalie,
Labanowski Jérôme,
Ghrairi Tawfik,
Hani Khaled,
Frère Jacques,
Imbert Christine
Publication year - 2015
Publication title -
chemistry and biodiversity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.427
H-Index - 70
eISSN - 1612-1880
pISSN - 1612-1872
DOI - 10.1002/cbdv.201400343
Subject(s) - rosmarinus , thymus vulgaris , essential oil , officinalis , traditional medicine , carvacrol , legionella pneumophila , lamiaceae , biology , broth microdilution , microbiology and biotechnology , botany , chemistry , antimicrobial , food science , minimum inhibitory concentration , bacteria , medicine , genetics
Abstract The aim of this study was to investigate the composition of six essential oils extracted from Tunisian plants, i.e., Artemisia herba‐alba Asso , Citrus sinensis (L.) Osbeck , Juniperus phoenicea L., Rosmarinus officinalis L., Ruta graveolens L., and Thymus vulgaris L., and to evaluate their activity against Legionella pneumophila (microdilution assays). Eight Legionella pneumophila strains were studied, including the two well‐known serogroup 1 Lens and Paris strains as controls and six environmental strains isolated from Tunisian spas belonging to serogroups 1, 4, 5, 6, and 8. The essential oils were generally active against L. pneumophila. The activities of the A. herba‐alba, C. sinensis , and R. officinalis essential oils were strain‐dependent, whereas those of the J. phoenicea and T. vulgaris oils, showing the highest anti‐ Legionella activities, with minimum inhibitory concentrations ( MIC s) lower than 0.03 and lower than or equal to 0.07 mg/ml, respectively, were independent of the strains' serogroup. Moreover, the microorganisms treated with T. vulgaris essential oil were shorter, swollen, and less electron‐dense compared to the untreated controls. Isoborneol (20.91%), (1 S )‐ α ‐pinene (18.30%) β ‐phellandrene (8.08%), α ‐campholenal (7.91%), and α ‐phellandrene (7.58%) were the major components isolated from the J. phoenicea oil, while carvacrol (88.50%) was the main compound of the T. vulgaris oil, followed by p ‐cymene (7.86%). This study highlighted the potential interest of some essential oils extracted from Tunisian plants as biocides to prevent the Legionella risk.