Isolation and Evaluation of Antimicrobial Activity of Endophytic Actinobacteria from horsetail Plant (Equisetum diffusum D. Don) against Bacterial Disease in Aquatic Animals

Author: Nguyen Van Thanh, Trinh Thi Trang and Nguyen Thanh Hai

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Abstract

Aquaculture is rapidly expanding in area andin intensity, however, there are serious problems caused by bacterial infection. The use of antibiotics is not sufficient to mitigate the outbreaks due to increase in antibiotic resistance. Therefore, to overcome the challenges of antibiotic resistance, antimicrobial compounds with a new mechanistic approach should be urgently sought. The aim of this study is to isolate and evaluate antimicrobial activity of endophytic actinobacteria from Horsetail plant (May Chang, Equisetum diffusum D. Don) against two pathogenic bacterial species Aeromonas hydrophila GL14, A. veronii HY15 causing severe disease on common carp and catfish. The results showed that 9/32 (28.2%) endophytic actinobacteria isolates could inhibit at least one target pathogenic bacteria. Three isolates TB13, TB21 and TB17 showed the highest antibacterial response with minimium inhibitory concentration (MIC) ranging from 93.3 to 300 µl/mL. Amongst these, the lowest value is for TB

Keywords

May Chang, actinobacteria, Aeromonas, common carp, catfish

Conclusion

. There were 8 out of total 26 EA strains in Horsetail plant exhibiting antimicrobial effect on the two pathogenic bacteria A. hydrophila GL14, A. Veronii HY15 which cause diseases in common carp and catfish. Three EA strains TB21, TB13 and TB17 showed wide inhibitory zones ranging from 26.2 to 17.5 mm. 2. MICs of 3 strains TB21, TB13 and TB17 displayed no significant difference in a range of 102.4 to 267.3 µl/mL against both tested bacteria. 3. The combination of TB13 andTB17 showed synergistic effect against two tested bacteria to enhance antimicrobial activity at least 4 times compared with single strain. This result could be of potential and promising application for sustainable therapy in aquaculture.

References

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How to cite this article

Thanh, Nguyen Van, Trang, Trinh Thi and Hai, Nguyen Thanh (2019). Isolation and Evaluation of Antimicrobial Activity of Endophytic Actinobacteria from horsetail Plant (Equisetum diffusum D. Don) against Bacterial Disease in Aquatic Animals. Biological For