| dc.description.abstract | AHPND (Acute Hepatopancreatic Necrosis Disease) was first emerged in China in 2009, spread to Vietnam in 2010, and expand throughout Southeast Asia countries afterward. It has been attacked to shrimp production and cause negative effects to the aquaculture industry in Vietnam which was lost the economic estimated 7.2 million USD in 2012. The causative agent of this disease is Vibrio parahamolyticus bringing two toxic genes named Pir-A and Pir-B inserted into 69 kb plasmid in the bacterial cell. The purpose of this study was to evaluate the ethanol extract effect of Urena lobata and Croton tonkinensis in inhibiting the growth of V. parahaemolyticus causing AHPND (VPAHPND) in Penaeus vannamei. The result of in vitro test by disk diffusion method showed that V. parahaemolyticus were susceptible to these extracts with bacterial inhibiting zone of 15 ± 0.3 (mm) and 18 ± 0.3 (mm), respectively. For the challenge test via diets, P. vannamei were fed 2% and 4% (w/w) of two these extracts for 7 days and the challenge test was compared with that of control groups (positive control group and negative control group) . The results also showed that the survival percentage of the treatment groups, after the 7-day infection with VPAHPND, were statistically significant difference (P<0.05) in comparison with that of the control group. From the experimental results, this study can conclude that the Croton tonkinensis extract has antibacterial activity against VPAHPND and it is able to prevent AHPND in white-leg shrimp. Key word: Urena lobate, Croton tonkinensis gagnep, Vibrio parahaemolyticus, AHPND, Penaeus vannamei. | en_US |
