INTERACTION EFFECTS OF LITSEA CUBEBA ESSENTIAL OIL AND ANTIBIOTICS ON ANTIBACTERIAL ACTIVITY AGAINST PATHOGENIC BACTERIA IN AQUACULTURE
Keywords:Litsea cubeba, essential oil, antibacterial activity, synergistic effect.
In this study, the interaction effects of Litsea cubeba essential oil (EO) and two antibiotics (ABs) on the antibacterial activity against pathogenic bacteria in aquaculture were investigated. Two reference strains (Escherichia coli ATCC 25922 (E. coli ATCC 25922) and Vibrio parahaemolyticus ATCC 17802 (V. parahaemolyticus ATCC 17802)) and six locally isolated aquatic pathogenic strains (E. coli 9C48, E. coli 11C123, Vibrio 2S4, Vibrio 2N38, V. parahaemolyticus ND201 and V. parahaemolyticus TB81) were used. The inhibitory effects of individual antimicrobial agent (L. cubeba EO, nalidixic acid, and oxytetracycline) were tested against eight strains by using broth microdilution assay in 96-well microplates. A higher inhibitory effect of L. cubeba EO was observed against isolated aquatic pathogenic (MIC = 1.15 - 2.30 mg/mL) than that in the reference strains (MIC = 5.53 mg/mL). The combination effects of L. cubeba EO and ABs often used in the treatment of bacteria effects in aquaculture (nalidixic acid and oxytetracycline) were evaluated by the checkerboard method. Fractional Inhibitory Concentration (FIC) values were determined to characterize the interaction among combinations. Out of 16 AB-EO combinations tested, 11 of them showed a synergistic effect (FIC ≤ 0.5), 3 of them showed an additional effect (0.5 < FIC ≤ 1.0) and 2 of them showed indifferent effect (1 < FIC ≤ 4), no antagonistic effect was observed. The antimicrobial synergy of EO and AB could enhance efficacy, reduce toxicity, decrease adverse side effects, and lower the dose of ABs used in aquaculture.
How to Cite
Authors who publish with Vietnam Journal of Science and Technology agree with the following terms:
- The manuscript is not under consideration for publication elsewhere. When a manuscript is accepted for publication, the author agrees to automatic transfer of the copyright to the editorial office.
- The manuscript should not be published elsewhere in any language without the consent of the copyright holders. Authors have the right to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal’s published version of their work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are encouraged to post their work online (e.g., in institutional repositories or on their websites) prior to or during the submission process, as it can lead to productive exchanges or/and greater number of citation to the to-be-published work (See The Effect of Open Access).