Evaluation of the single and combined antibacterial efficiency of essential oils for controlling Campylobacter coli, Campylobacter jejuni, Escherichia coli, Staphylococcus aureus, and mixed cultures

Abstract

Single and combined antibacterial activities of cumin, cardamom, and dill weed essential oils against Campylobacter jejuni, Campylobacter coli, Escherichia coli, Staphylococcus aureus, and mixed cultures were determined by using the broth microdilution method for determining minimum inhibition concentrations. Among the bacteria tested, C. coli and C. jejuni were generally more susceptible to essential oils, with lower minimum inhibition concentrations. The minimum inhibition concentration values were obtained against Gram‐negative and Gram‐positive bacteria tested within the range of 0.012–15.00 and 3.75–15.00 μL/mL, respectively. Fractional inhibitory concentrations (FICs) were also calculated to evaluate the antimicrobial activities of essential oil combinations. Although the combined effects of essential oils changed depending on the strain and the type of essential oils used, generally the use of combinations increased the efficacy of the essential oils. Interestingly, according to the FIC index, the most synergetic effect was against C. coli and C. jejuni. This study has demonstrated the potential use of cardamom, cumin, and dill weed essential oils, and their combinations, against important pathogenic bacteria and their mixed cultures.

Antibacterial, Antifungal, Antimycotoxigenic, and Antioxidant Activities of Essential Oils: An Updated Review

“…The increase in the antibacterial activity of EOs, when used in combination, has been proposed by several researchers. Not only synergistic but also additive, non-interactive, and antagonistic interactions have been reported [ 5 ]. Within these interactions, EO combinations that have synergistic and additive effects have been suggested for food applications [ 31 ].…”

“…While no antagonism was reported for the combinations of cardamom, cumin, and dill weed, the highest antimicrobial activity was observed in a cardamom and dill weed EO combination. This high antimicrobial activity was attributed to the synergistic effect of 1,8-cineole content (29.2%) of cardamom EO and limonene content (27.4%) of dill weed EO [ 5 ]. A synergistic effect was also reported for the combination of cinnamon (cinnamaldehyde as the main constituent) and clove (eugenol as the main constituent) against Staphylococcus aureus , Listeria monocytogenes , Salmonella typhimurium , and Pseudomonas aeruginosa and synergistic antifungal activity against Aspergillus niger [ 34 ].…”

“…The antimicrobial activity of EOs mainly depends on the chemical composition as well as the parts of the plants. On the other hand, Gram-positive and Gram-negative bacteria differ in terms of their sensitivity against EOs [ 5 , 37 ]. These differences have been explained by several mechanisms including the more resistant nature of Gram-negative bacteria due to their double layer of phospholipids [ 21 ].…”

“…[ 44 ], their mixtures showed the highest antibacterial activity against Escherichia coli , Campylobacter spp. and Staphylococcus aureus [ 5 ]. Similarly, the antibacterial activities of cinnamon and clove EO were tested not only individually but also in combination.…”

“…Antimicrobial and antioxidant activities of EOs have been investigated in several studies, and these studies have shown antimicrobial and antioxidant activities as the most common biological activities in EOs, but some other activities of EOs, including antiviral, insecticidal, angiotensin-converting enzyme, amylase and glucosidase enzyme, and xanthine oxidase inhibitory activities, etc., still need more investigation. In addition to their individual use, EO combinations can be used in binary or ternary mixtures to improve the mixtures’ biological activities [ 5 ].…”