Assessment of the antibacterial activity of four essential oils and the biobactericide Neco.

Abstract

<p>The purpose of this study was to assess <em>in vitro</em> the activity of four essential oils (<em>Cymbopogon citratus, Eucalyptus citriodora, Lippia multiflora, Melaleuca quinquenervia</em>) and the biobactericide Neco® on Gram-positive bacteria.</p><p><strong>T</strong>he aromatogram and antibiogram were assessed by the agar well diffusion method and the Muller Hinton disk-agar diffusion method, respectively. Also, the minimum inhibitory concentration and the minimum bactericidal concentration were determined by the microdilution method in liquid medium.</p><p>The aromatogram showed that the biobactericide Neco® induced the largest inhibition diameters (34.53 ± 11.82 - 43.92 ± 5.38 mm) of all strains combined, followed by the essential oils of <em>Eucalyptus Citriodora</em> (30.01 ± 3.02 - 41.89 ± 1.77 mm) and <em>Lippia multiflora</em> (20.72 ± 4.72 - 37.61 ± 2.80 mm). However, the essential oils of <em>Melaleuca quinquenervia</em> (19.99 ± 3.93 - 26.20 ± 13.27 mm) and <em>Cymbopogon citratus</em> (13.52 ± 3.59 - 29.08 ± 2.35 mm) had the smallest inhibition diameters. Moreover, the comparison of the activities of the aromatogram and antibiogram revealed generally that activities were higher with essential oils than with antibiotics.</p><p>At the end of this study, the essential oils of <em>Cymbopogon citratus</em>, <em>Eucalyptus citriodora, Lippia multiflora, Melaleuca quinquenervia</em> and the biobactericide Neco® had an antibacterial activity on Gram+ bacteria.</p><p><strong><br /></strong></p>

The Novel Quantitative Assay for Measuring the Antibiofilm Activity of Volatile Compounds (AntiBioVol)

“…However, while the testing methods for EOs liquid fractions rely on well-defined EUCAST (European Committee for Antimicrobial Susceptibility Testing) and pharmacopeial recommendations [15,16], the methodology of testing EOs' volatile activity against microbes is highly diversified. These differences concern not only the experimental setting itself but also the various types of microbial aggregates scrutinized (lawn, biofilm) [17][18][19]. Moreover, also, the EOs are highly intra-species differentiated (with regard to the composition and concentration of antimicrobial compounds) caused by geographic and location factors, seasonal effects, and genetic factors, which determine the so-called chemotypes commonly found in EO-bearing plant species [20].…”

Chemical Composition and Antibacterial Activity of Lippia multiflora Moldenke Essential Oil from Different Regions of Angola

“…The antimicrobial activity of any essential oil is not attributable to just one mechanism but to several ones widely described in the literature [ 89 ]. Factors such as climatic and environmental conditions, the origin of the plant, the plant’s adaptive metabolism, the harvesting season, the part of the plant involved in the extraction, the distillation conditions, the microbiological methods used, as well as the susceptibility of the bacterial strains would make it difficult to compare the results obtained by different groups of researchers [ 117 , 118 ].…”

Antimicrobial Secondary Metabolites from the Mangrove Plants of Asia and the Pacific

“…S.T. Blake ( Myrtaceae ) are strongly and broadly antibacterial and antifungal [ 135 , 136 , 137 , 138 ]. The essential oil of M. quinquenervia repressed Phytophthora cactorum [ 139 ] and was strongly fungicidal for filamentous fungi [ 140 ].…”