Research for the potential of some plant extracts in the prevention of many antibiotic resistance bacteria that cause disease on climbing perch (Anabas testudineus)
Abstract
Introduction: Industrial feed in fish farming merely covers nutritional demands and does not stimulate improved immunity in fish. Additionally, antibiotic misuse is hazardous to both the environment and human health. Therefore, for quality and safety, the most secure approach is to employ the huge supply of Vietnamese medicinal plants in fish farm food supplements.
Materials and methods: EtOH extract of the leaves of A. occidentale TD1, V. negundo TD2, V. rotundifolia TD3, A. aureum L TD4, J. subtriplinerve Blume TD5 collected in Vinh Long province, Vietnam based on in vitro antibacterial assessment by agar plate diffusion method and MIC, in vivo evaluation of virulence test by artificial infection with Kosakonia sacchari bacteria on the experimental fish model Anabas testudineus and investigate the activity of plant extracts when mixed into the feed.
Result: Antibacterial test by agar plate diffusion method showed that TD1 extract gave the best antibacterial result along with a concentration of 12.5 µg/ml. In the experiment to evaluate the virulence of the isolated K. sacchari strain, the result was that the strain was lethal to 87.6% of fish after 24 hours of injection at 105 CFU/ml, and the minimum lethality threshold LD50 was recorded in strains of 3.16 × 104 CFU/ml. The results were obtained in the experiment to evaluate the activity of plant extracts when mixed into feed. Feed containing TD1 protected fish from the artificial lethal agent K. sacchari (survival rate reaches 93%) and also helped to increase the weight gain of fish up to 22.8g.
Conclusion: EtOH leaf extract of A. occidentale TD1 exhibits the strongest antibacterial activity and can protect perch A. testudineus against multi-antibiotic-resistant strains of K. sacchari. There is an initial assessment of the potential of Vietnamese medicinal plants to gradually replace antibiotics, aiming for safety in farming, food production, and consumption. Following that, the idea might be carried out on a bigger scale as pilot models or fish farms to become a new source of commercial animal fodder.
