| Main results | Theoretical results:
- The results of the isolation and assessment of the multi-antibiotic resistance in pathogenic bacteria from diseased Anabas testudineus perch collected from fish hatcheries.
- The results of virulence testing in perch models and identification of multi-antibiotic resistant and highly lethal bacteria.
- The results of antibacterial activity, and plant bioactives and extracts as feed additives in perch models compared with antibiotics in vitro and in vivo.
Applied results:
- The project findings established a scientific basis for further research on antibiotic resistance in pathogenic bacteria from A. testudineus perch in Vietnam, as well as treatments based on plant bioactives and extracts to gradually replace antibiotics in aquaculture in Vietnam.
- The project findings of screening and research on plant bioactives and extracts provided a database on freshwater fish, commercial fish, and fish hatcheries, solving scientifically and thoroughly the challenges posed, contributing to the integration of scientific research into practical application in the aqua feed production process, bringing numerous prospects to the aquaculture industry in Vietnam.
- The project increased the scientific capability and project implementation ability of VAST's scientific staff and strengthened collaborations among VAST's units, (VAST: Vietnam Academy of Science and Technology), including the Graduate University of Science and Technology, the Institute of Natural Products Chemistry, and other institutions.
- The initiative elevated VAST and VAST's units to the forefront of scientific research and training in the country and area. |
| Novelty and actuality and scientific meaningfulness of the results | - The project selected and isolated 12 bacteria groups from perch farms in HCM City (District 12, District 9, District 8, Thu Duc, Can Gio,…). Based on morphological, physiological, and biochemical characteristics, the bacteria were identified as belonging to Yersinia spp., Vibrio spp., Pseudomonas spp., Shigella spp., Staphylococcus spp., Klebsiella spp., Enterobacter spp., and E. coli. Bacteria all have high multi-antibiotic resistance, most of which are all resistant to ampicillin, cephalexin, chloramphenicol, amoxicillin, erythromycin, which are the prohibited antibiotics in seafood production, and trade (Circular No. 10/2016/TT-BNNPTNT). Meanwhile, the perch farm in HCM City would have a circulating multi-antibiotic resistant bacteria with a wide range of resistance.
- The project isolated and identified 4 bacteria strains with significant antibiotic resistance, high pathogenicity in vulnerable perch models with evident clinical symptoms, and 16S rRNA sequences tested Aeromonas dhakensis (99,84%), Pseudomonas aeruginosa (99,77%), Edwardsiella ictaluri (99,44%), và Kosakonia sacchari (99,93%, this strain was shown to be causing disease in fish for the first time). In particular, A. dhakensis VIII-NV5M, which is the most frequent infection in aquaculture, had strong antibiotic resistance, and the highest mortality with LD50 = 105,1 (= 1,26 × 105 CFU/ml) in the sensitive co-infection perch models, was chosen as a pathogenic bacteria for the antibacterial activity, and plant bioactives and extracts as feed additives in perch models compared with antibiotics in vitro and in vivo.
- The project then investigated plant bioactives and extracts of B. macrophylla TD1, A. occidentale TD2, R. officinalis TD3, L. angustifolia TD4, P. macrostachya TD5, and A. sambac TD6 in vitro and in vivo. In which, B. macrophylla leaf extracts had the most antibacterial activity in vitro, in suppressing all four bacteria strains: A. dhakensis (the most virulent strain), K. sacchari, E. ictaluri, and P. aeruginosa. B. macrophylla extracts also had the effectiveness in shielding perch against natural and artificial fatal agents in susceptible perch models in vivo. Since then, the project's outcomes have shifted toward the adoption of safe and effective medicines, which will eventually replace antibiotics in aquaculture. |
| Products of the project | International Publication ISI/Scopus:
4. Hai Ha Pham Thi, Minh Quan Pham, Quoc Toan Tran, Quoc Long Pham, Kien Cuong Tran, Long Giang Bach, Thanh Luan Nguyen. Effects of antibiotic on climbing perch, Anabas testudineus, exposed to Aeromonas dhakensis as a second infection. Acta Trop.2022 Feb;226: 106281. doi: 10.1016/j.actatropica.2021.106281. (ISI Q1)
5. Thanh Luan Nguyen, Kien Cuong Tran, Thu Nha Nguyen Thi, Lan Phan Hoang Nguyen, Nga Tran Thi, Huyen Mai Thi Ngan, Minh Quan Pham, Quoc Toan Tran, Quoc Long Pham, Long Giang Bach, Hai Ha Pham Thi. Identification of multi-antibiotic resistant bacteria isolated from Vietnamese climbing perch (Anabas testudineus) on fish farms in Ho Chi Minh City, Vietnam. IOP Conf. Series: Earth and Environmental Science 947 (2021) 012036. doi:10.1088/1755-1315/947/1/012036 (Scopus)
Domestic Publication:
6. Pham Thi Hai Ha, Tran Kien Cuong, Nguyen Thi Thu Nha, Nguyen Phan Hoang Lan, Nguyen Huu Thuan Anh, Bach Long Giang, Pham Minh Quan, Pham Quoc Long, Nguyen Thanh Luan. A preliminary study on biological activities in vitro of Bouea macrophylla Griff leaf extract. Vietnam Journal of Biotechnology, Vietnam Academy of Science and Technology (Accepted letter 2021) (VAST2)
Scientific and technological products: (Academy-required files and hard copies)
01 Final report of the project
01 Vietnamese summary of the project
01 English summary of the project
Education/training: 03 students' training:
- Tran Thi Nga, Nguyen Tat Thanh University, Year: 2022, rank: Good.
- Mai Thi Ngan Huyen, Nguyen Tat Thanh University, Year: 2022, rank: Good.
- Huynh Tran Thuc Doan, Nguyen Tat Thanh University, Year: 2022, rank: Good. |
