{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,11]],"date-time":"2026-08-11T05:28:02Z","timestamp":1786426082570,"version":"build-2736575974"},"reference-count":41,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2026,8,7]],"date-time":"2026-08-07T00:00:00Z","timestamp":1786060800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pathogens"],"abstract":"<jats:p>Aeromonas species are among the most important Gram-negative pathogens in aquaculture and represent a One Health concern, as antibiotic-resistant strains circulate at the interface between ornamental fish, the aquatic environment and humans. This study evaluated the in vitro antibacterial activity of four commercial essential oils from tea tree (Melaleuca alternifolia), peppermint (Mentha piperita), rosemary (Rosmarinus officinalis) and lavandin (Lavandula hybrida) against sixteen oxytetracycline-resistant Aeromonas hydrophila and A. veronii isolated from moribund ornamental fish. All tested bacteria were resistant to oxytetracycline (MIC 8\u201316 \u00b5g\/mL). Minimum inhibitory (MIC) and minimum bactericidal (MBC) concentrations were determined by broth microdilution. All EOs inhibited every isolate, but their bactericidal capacity differed markedly. Rosemary oil showed the lowest MIC and MBC ranks and the most consistent values, followed by tea tree and lavandin; all three were bactericidal. Peppermint oil, despite a low MIC, showed a high MBC and was bacteriostatic. These findings indicate that the EOs of rosemary, tea tree and lavandin are promising in vitro candidates for use against oxytetracycline-resistant Aeromonas in aquaculture, in line with the One Health approach, and warrant further evaluation.<\/jats:p>","DOI":"10.3390\/pathogens15080831","type":"journal-article","created":{"date-parts":[[2026,8,7]],"date-time":"2026-08-07T16:00:43Z","timestamp":1786118443000},"page":"831","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Antibacterial Activity of Essential Oils as Phytotherapeutic Alternatives Against Aeromonas spp. from Ornamental Fish"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1940-7949","authenticated-orcid":false,"given":"Faik Sertel","family":"Se\u00e7er","sequence":"first","affiliation":[{"name":"Department of Fisheries and Aquaculture, Faculty of Agriculture, Ankara University, 06110 Ankara, T\u00fcrkiye"},{"name":"Aquaterra Ltd., Ankara University Tecnopolis, 06830 Ankara, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Buller, N.B. (2014). Bacteria and Fungi from Fish and Other Aquatic Animals: A Practical Identification Manual, CABI.","DOI":"10.1079\/9781845938055.0000"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Pepi, M., and Focardi, S. (2021). Antibiotic-resistant bacteria in aquaculture and climate change: A challenge for health in the Mediterranean area. Int. J. Environ. Res. Public Health, 18.","DOI":"10.3390\/ijerph18115723"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Adisasmito, W.B., Almuhairi, S., Behravesh, C.B., Bilivogui, P., Bukachi, S.A., Casas, N., Becerra, N.C., Charron, D.F., Chaudhary, A., and Zanella, J.R.C. (2022). One Health: A new definition for a sustainable and healthy future. PLoS Pathog., 18.","DOI":"10.1371\/journal.ppat.1010537"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"153626","DOI":"10.1016\/j.phymed.2021.153626","article-title":"Antibacterial plant compounds, extracts and essential oils: An updated review on their effects and putative mechanisms of action","volume":"90","author":"Micol","year":"2021","journal-title":"Phytomedicine"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Bukvi\u010dki, D., D\u2019Alessandro, M., Rossi, S., Siroli, L., Gottardi, D., Braschi, G., Patrignani, F., and Lanciotti, R. (2023). Essential oils and their combination with lactic acid bacteria and bacteriocins to improve the safety and shelf life of foods: A review. Foods, 12.","DOI":"10.3390\/foods12173288"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"375","DOI":"10.34172\/jhp.2022.46","article-title":"Analysis of the chemical compositions of six essential oils and evalua-tion of their antioxidant and antibacterial activities against some drug-resistant bacteria in aquaculture","volume":"11","author":"Chbel","year":"2022","journal-title":"J. Herbmed Pharmacol."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Dawood, M.A.O., El Basuini, M.F., Zaineldin, A.I., Y\u0131lmaz, S., Hasan, M.T., Ahmadifar, E., El Asely, A.M., Abdel-Latif, H.M.R., Alagawany, M., and Abu-Elala, N.M. (2021). Antiparasitic and antibacterial functionality of essential oils: An alternative approach for sustainable aquaculture. Pathogens, 10.","DOI":"10.3390\/pathogens10020185"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Dawood, M.A.O., El Basuini, M.F., Y\u0131lmaz, S., Abdel-Latif, H.M.R., Alagawany, M., Kari, Z.A., Abdul Razab, M.K.A., Hamid, N.K.A., Moon-manee, T., and Van Doan, H. (2022). Exploring the roles of dietary herbal essential oils in aquaculture: A review. Animals, 12.","DOI":"10.3390\/ani12070823"},{"key":"ref_9","first-page":"223","article-title":"Antibiotic susceptibility of Lactococcus garvieae in rainbow trout (Oncorhynchus mykiss) farms","volume":"52","author":"Kav","year":"2008","journal-title":"Bull. Vet. Inst. Pulawy"},{"key":"ref_10","first-page":"23","article-title":"A study on the antimicrobial resistance of Lactococcus garvieae","volume":"8","author":"Korun","year":"2021","journal-title":"Acta Aquat."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Kozics, K., Mes\u00e1ro\u0161ov\u00e1, M., \u0160ramkov\u00e1, M., Bu\u010dkov\u00e1, M., Pu\u0161k\u00e1rov\u00e1, A., Galov\u00e1, D., and Pangallo, D. (2025). Evaluation of bioactivity of essential oils: Cyto-toxic\/genotoxic effects on colorectal cancer cell lines, antibacterial activity, and survival of lactic acid bacteria. Molecules, 30.","DOI":"10.3390\/molecules30040890"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Lupia, C., Castagna, F., Bava, R., Naturale, M.D., Zicarelli, L., Marrelli, M., Statti, G., Tilocca, B., Roncada, P., and Britti, D. (2024). Use of essential oils to counteract the phenomena of antimicrobial resistance in livestock species. Antibiotics, 13.","DOI":"10.3390\/antibiotics13020163"},{"key":"ref_13","unstructured":"Milija\u0161evi\u0107, M., Veskovi\u0107-Mora\u010danin, S., Babi\u0107 Milija\u0161evi\u0107, J., Petrovi\u0107, J., and Nastasijevi\u0107, I. (2024). Antimicrobial resistance in aquaculture: Risk mitigation within the One Health context. Foods, 13."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"e14088","DOI":"10.1016\/j.heliyon.2023.e14088","article-title":"A review on pathogenicity of Aeromonas hydrophila and their mitigation through medicinal herbs in aqua-culture","volume":"9","author":"Semwal","year":"2023","journal-title":"Heliyon"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"e565","DOI":"10.20950\/1678-2305.2020.46.3.565","article-title":"Antibacterial effects of seven essential plant oils on fish pathogens","volume":"46","author":"Baba","year":"2020","journal-title":"Bol. Inst. Pesca"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Hudecov\u00e1, P., Ko\u0161\u010dov\u00e1, J., Hajdu\u010dkov\u00e1, V., Kir\u00e1ly, J., and Hor\u0148\u00e1k, P. (2024). Antibacterial and antibiofilm activities of essential oils against Aeromonas spp. isolated from rainbow trout. Animals, 14.","DOI":"10.3390\/ani14223202"},{"key":"ref_17","first-page":"21456","article-title":"Antibacterial activity of essential oils and extracts of some medicinal plants against bacterial fish pathogens","volume":"73","author":"Metin","year":"2021","journal-title":"Isr. J. Aquac. Bamidgeh"},{"key":"ref_18","first-page":"574","article-title":"The antibacterial effects of Cuminum cyminum L. and Rosmarinus officinalis extracts and essential oil against Lactococcus garvieae in laboratory conditions on rainbow trout","volume":"4","author":"Pour","year":"2014","journal-title":"Eur. J. Exp. Biol."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Rajendran, S., Heinzmann, B.M., Cargnelutti, J.F., and Baldisserotto, B. (2026). Utilization of plant-derived essential oils as natural alternatives for control-ling fish pathogens: A critical review of their use against Aeromonas hydrophila. Fishes, 11.","DOI":"10.3390\/fishes11020120"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Zhong, W., Chen, K., Yang, L., Tang, T., Jiang, S., Guo, J.-J., and Gao, Z. (2022). Essential oils from Citrus unshiu Marc. effectively kill Aeromonas hydrophila by destroying cell membrane integrity, influencing cell potential, and leaking intracellular substances. Front. Microbiol., 13.","DOI":"10.3389\/fmicb.2022.869953"},{"key":"ref_21","first-page":"176","article-title":"Biological activity of red pitaya extracts on Lactococcus garvieae and Vibrio alginolyticus","volume":"13","author":"Celik","year":"2023","journal-title":"Manas J. Agric. Vet. Life Sci."},{"key":"ref_22","first-page":"273","article-title":"Determination of the in vitro effect of lemongrass (Cymbopogon flexuosus) oil against fish pathogenic bacteria isolated from cultured olive flounder (Paralichthys olivaceus)","volume":"56","author":"Pathirana","year":"2019","journal-title":"Slov. Vet. Res."},{"key":"ref_23","first-page":"26","article-title":"Evaluation of antibacterial activity of macerated oil from lemon balm (Melissa officinalis L.), thyme (Thymus vulgaris L.), mint (Mentha longifolia L.) and marigold (Calendula officinalis) with modified tube dilution method","volume":"12","year":"2017","journal-title":"J. New World Sci. Acad. Ecol. Life Sci."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Dugo, G., and Di Giacomo, A. (2002). Citrus: The Genus Citrus, Taylor & Francis.","DOI":"10.1201\/9780203216613"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"142","DOI":"10.1016\/j.vetimm.2013.11.009","article-title":"The use of eugenol against Aeromonas hydrophila and its effect on hematological and immunological parameters in silver catfish (Rhamdia quelen)","volume":"157","author":"Sutili","year":"2014","journal-title":"Vet. Immunol. Immunopathol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"716","DOI":"10.1111\/raq.12197","article-title":"Plant essential oils as fish diet additives: Benefits on fish health and stability in feed","volume":"10","author":"Sutili","year":"2018","journal-title":"Rev. Aquac."},{"key":"ref_27","unstructured":"Clinical and Laboratory Standards Institute (CLSI) (2015). Performance Standards for Antimicrobial Susceptibility Testing of Bacteria Isolated from Aquatic Animals, CLSI. [3rd ed.]. VET04."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1038\/s44259-024-00051-6","article-title":"Antibiotic susceptibility testing using minimum inhibitory concentration (MIC) assays","volume":"2","author":"Mahmood","year":"2024","journal-title":"npj Antimicrob. Resist."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Teh, C.H., Nazni, W.A., Nurulhusna, A.H., Norazah, A., and Lee, H.L. (2017). Determination of antibacterial activity and minimum inhibitory concentra-tion of larval extract of fly via resazurin-based turbidometric assay. BMC Microbiol., 17.","DOI":"10.1186\/s12866-017-0936-3"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"266","DOI":"10.4103\/jioh.jioh_5_22","article-title":"Evaluating the antibacterial efficacy and minimal bactericidal concentration (MBC) of three different herbal extracts on recalcitrant endodontic pathogens: An in vitro study","volume":"14","author":"Rajakumar","year":"2022","journal-title":"J. Int. Oral Health"},{"key":"ref_31","first-page":"1571","article-title":"Evaluation of antibacterial effects of marshmallow (Althaea officinalis) on four strains of bacteria","volume":"5","author":"Zarei","year":"2013","journal-title":"Int. J. Agric. Crop Sci."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"446","DOI":"10.1016\/j.fct.2007.09.106","article-title":"Biological effects of essential oils\u2014A review","volume":"46","author":"Bakkali","year":"2008","journal-title":"Food Chem. Toxicol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"328","DOI":"10.1111\/jam.13911","article-title":"The effects of essential oils and their major compounds on fish bacterial pathogens\u2014A review","volume":"125","author":"Fausto","year":"2018","journal-title":"J. Appl. Microbiol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"82","DOI":"10.1016\/j.micpath.2016.07.002","article-title":"In vivo bactericidal effect of Melaleuca alternifolia essential oil against Aeromonas hydrophila: Silver catfish (Rhamdia quelen) as an experimental model","volume":"98","author":"Souza","year":"2016","journal-title":"Microb. Pathog."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"209","DOI":"10.1080\/10412905.2020.1741457","article-title":"Composition of essential oils of Mentha spe-cies and their antimicrobial activity against Aeromonas spp","volume":"32","author":"Chagas","year":"2020","journal-title":"J. Essent. Oil Res."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Kot, B., Kwiatek, K., Janiuk, J., Witeska, M., and P\u0119kala-Safi\u0144ska, A. (2019). Antibacterial activity of commercial phytochemicals against Aeromonas species isolated from fish. Pathogens, 8.","DOI":"10.3390\/pathogens8030142"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1016\/j.jare.2013.12.007","article-title":"An investigation of the bactericidal activ-ity of selected essential oils to Aeromonas spp","volume":"6","author":"Starliper","year":"2015","journal-title":"J. Adv. Res."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"6","DOI":"10.1186\/s13028-020-0504-y","article-title":"Antimicrobial resistance patterns of motile aeromonads isolated from farmed and wild freshwater fish in northern Italy","volume":"62","author":"Borella","year":"2020","journal-title":"Acta Vet. Scand."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"531","DOI":"10.1111\/lam.13363","article-title":"Antimicrobial resistance and resistance gene characteristics of motile Aeromonas spp. isolated from fish farms","volume":"71","author":"Duman","year":"2020","journal-title":"Lett. Appl. Microbiol."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Sherif, A.H., and Kassab, A.S. (2023). Multidrug-resistant Aeromonas bacteria prevalence in Nile tilapia broodstock. BMC Microbiol., 23.","DOI":"10.1186\/s12866-023-02827-8"},{"key":"ref_41","unstructured":"European Parliament and Council (2010). Directive 2010\/63\/EU on the protection of animals used for scientific purposes. Off. J. Eur. Union, L276, 33\u201379."}],"container-title":["Pathogens"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-0817\/15\/8\/831\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,11]],"date-time":"2026-08-11T04:35:05Z","timestamp":1786422905000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-0817\/15\/8\/831"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,7]]},"references-count":41,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2026,8]]}},"alternative-id":["pathogens15080831"],"URL":"https:\/\/doi.org\/10.3390\/pathogens15080831","relation":{},"ISSN":["2076-0817"],"issn-type":[{"value":"2076-0817","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,7]]}}}