Antibacterial Effects of Essential Oils of Seven Medicinal-Aromatic Plants Against the Fish Pathogen Aeromonas veronii bv. sobria : To Blend or Not to Blend?

• Published in: Molecules (Basel, Switzerland) Vol. 26; no. 9; p. 2731
• Main Authors: Mandalakis, Manolis, Anastasiou, Thekla I, Martou, Natalia, Keisaris, Sofoklis, Greveniotis, Vasileios, Katharios, Pantelis, Lazari, Diamanto, Krigas, Nikos, Antonopoulou, Efthimia
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 06.05.2021; MDPI
• Subjects: Aeromonas veronii; Aeromonas veronii - drug effects; Animals; Anti-Bacterial Agents - pharmacology; Antibacterial activity; Antibiotics; Antimicrobial activity; Antimicrobial agents; Apiaceae; Aquaculture; Bacterial infections; bacterial pathogens; Catfish; Chemistry Techniques, Synthetic; Daucus carota; Drug Synergism; essential oil combinations; Essential oils; Fish; Fishes - microbiology; Gas Chromatography-Mass Spectrometry; Gram-Negative Bacterial Infections - prevention & control; Gram-Negative Bacterial Infections - veterinary; Greek native MAPs; Infections; Inhibitory Concentration 50; Investigations; Melissa; Mentha; Microbial Sensitivity Tests; natural products; Oils & fats; Oils, Volatile - pharmacology; Oregano; Origanum; Pathogens; Plant Extracts - pharmacology; Plants, Medicinal - chemistry; Rosmarinus; Satureja; synergistic effects; Greece; Greek native MAPs; aquaculture; natural products; synergistic effects; antimicrobial activity; bacterial pathogens; essential oil combinations
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules26092731

Despite progress achieved, there is limited available information about the antibacterial activity of constituents of essential oils (EOs) from different medicinal-aromatic plants (MAPs) against fish pathogens and the complex interactions of blended EOs thereof. The present study aimed to investigate possible synergistic antimicrobial effects of EOs from seven Greek MAPs with strong potential against bv. a fish pathogen associated with aquaculture disease outbreaks. The main objective was to evaluate whether blending of these EOs can lead to increased antimicrobial activity against the specific microorganism. A total of 127 combinations of EOs were prepared and their effect on bv. growth was tested in vitro. We examined both the inhibitory and bactericidal activities of the individual EOs and compared them to those of the blended EOs. The vast majority of the investigated combinations exhibited significant synergistic and additive effects, while antagonistic effects were evident only in a few cases, such as the mixtures containing EOs from rosemary, lemon balm and pennyroyal. The combination of EOs from Greek oregano and wild carrot, as well as the combinations of those two with Spanish oregano or savoury were the most promising ones. Overall, Greek oregano, savoury and Spanish oregano EOs were the most effective ones when applied either in pure form or blended with other EOs.