<i>Using </i><i>Wedelia chinensis to prevent </i><i>AH</i><i>P</i><i>ND by </i><i>V</i><i>ibrio parahaemolyticus</i><i> on shrimp </i><i>(</i><i>Penaeus vannamei</i><i>)</i>
Creators: name: NGOC, Tran Nguyen
Publisher: name: figshare
Year: 2024
Subjects: classificationCode: 300501
subject: Aquaculture

description: <b>ABSTRACT</b>White-leg shrimp (<i>Penaeus vannamei</i>) has a fast growth rate and good adaptability to environmental conditions, so it is widely farmed in Viet Nam and many countries worldwide. The disease is the biggest challenge for white-leg shrimp farming today, especially acute hepatopancreatic necrosis caused by <i>Vibrio parahaemolyticus</i> bacteria, one of the leading causes of reduced shrimp farming output. Antibiotics are often used to treat diseases caused by bacteria in aquatic animals. Still, they are ineffective against this disease and cause environmental pollution, loss of food hygiene and safety, and the creation of new strains. antibiotic-resistant bacteria. The thesis "Using <i>Wedelia chinensis</i> to prevent acute hepatopancreatic necrosis disease (AHPND) caused by <i>Vibrio parahaemolyticus</i> bacteria in white shrimp (<i>Penaeus vannamei</i>)" in Thua Thien Hue was carried out from 2021 to 2024 to determine the ability of AHPND extract to resist bacteria that cause acute hepatopancreatic necrosis disease (AHPND) on whiteleg shrimp to provide a safe and effective disease prevention solution for shrimp farming in Viet Nam. Research content includes: (1) Determining the biologically active ingredients in the plant; (2) Evaluate the ability of <i>W. chinensis</i> extract to resist <i>V. parahaemolyticus</i> bacteria causing acute hepatopancreatic necrosis disease in white shrimp; (3) Effect of Solanum extract on immune response in white-leg shrimp; (4) Evaluate the effectiveness of the <i>W. chinensis</i> extract procumbent on the ability to prevent acute hepatopancreatic necrosis disease in white-leg shrimp.<br>Research results on the composition of biologically active substances in the plant have identified several biologically active substances with good antibacterial properties present in three solvents: methanol, ethanol and water, such as alkaloid, flavonoid, polyphenol, carotenoid, fat, essential oil, tannin and organic acid, reducing compounds. The two active ingredients, total polyphenol and flavonoid, were quantified through two standard gallic acid and rutin curves. The total polyphenol content in the extract with the solvents methanol, ethanol and water is 74.33 ± 4.49 (mg GAE/g extract), respectively; 73.65 ± 5.44 (mg GAE/g extract); 53.07 ± 1.48 (mg GAE/g extract), flavonoid content in methanol solvent (24.59 ± 2.19 mg RE/g extract), ethanol (20.63 ± 4.30 mg RE /g extract) and water (3.20 ± 0.07 mg RE/g extract). At the same time, the total extraction efficiency of the plant was determined in the solvent methanol (11%), ethanol (11.3%) and water solvent (18.2%).<br>All <i>W. chinensis</i> extracts have strong antibacterial ability against <i>V. parahaemolyticus</i> with the diameter of the killing circle ranging from 12.1 to 14.7 mm, in which the extract of methanol solvent has the best antibacterial ability (antibacterial ring diameter up to 14.7 mm). The MIC values ​​of the <i>W. chinensis</i> extract against <i>V. parahaemolyticus</i> bacteria in methanol, ethanol and water solvents were 15.5 mg/L, 15.5 mg/L and 2500 mg/L, respectively. The MBC value of the <i>W. chinensis</i> extract in methanol solvent is 31.25 mg/L, ethanol is 62.5 mg/L), and water is 5000 mg/L.When fed white-leg shrimp with food supplemented with <i>W. chinensis</i> extract at different concentrations, it was 31.25 (NT1); 312.5 (NT2) and 625 mg/kg feed (NT3) for three weeks with one time and two times supplementation showed that shrimp had reasonable growth rate, improved immune response activity increased through Enhance blood cell indices, lysozyme enzyme activity, PO activity, SOD activity, phagocytic activity, and increase survival rate when infected with <i>V. parahaemolyticus</i>. The cumulative mortality rate in group 1 when challenged with <i>V. parahaemolyticus</i> bacteria in treatments supplemented with <i>W. chinensis</i> extract was 24% (NT1), 12% (NT2) and 16% (NT3), significantly lower than with the control treatment without adding extract (44 %). The cumulative death rate in group 2 was lower than in group 1 when infected with <i>V. parahaemolyticus</i> bacteria. The death rate in the control treatment (no extract added) accounted for 24%, NT1 (8%), NT2 (4 %) and NT3 (8 %). The protection rate of <i>W. chinensis</i> extract (RPS) added to the feed of treatments NT1, NT2 and NT3 was 63%, 69% and 55%, respectively.<br>The hepatopancreatic system's structural morphology is one indicator used to evaluate shrimp health. Histopathological analysis showed that adding the extract to the feed at dosages (31.25, 312.5, and 625 mg/kg of feed) did not change the structure of the hepatopancreas but also supported the growth rate and survival rate of shrimp. This is the first complete study on the plant that has identified biologically active ingredients that are effective in enhancing immune parameters and resistance to acute hepatopancreatic necrosis disease, which is fully implemented under the right conditions. <i>in vitro</i> and <i>in vivo</i> on white-leg shrimp.<b>Keywords:</b> Acute hepatopancreatic necrosis disease, <i>Wedelia chinensis</i> extract, immune response, growth and survival rate.<br><br>