The detection and analysis of acute hepatopancreatic necrosis disease (AHPND)and Vibrio in water or in Fenneropenaeus chinensis

In recent years,acute hepatopancreatic necrosis disease(AHPND)has broken out in all over the world and led to significant economic losses to shrimp farms.To gain further information of the outbreak of AHPND and Vibrios in Fenneropenaeus chinensis ponds,nPCR method and TCBS selective medium culture were used to detect samples collected from April to September 2018,respectively.The nPCR products revealed that the positive detection rate was higher in July and August,reached 15.6% and 25.0% respectively,whereas no positive samples were detected in other months.The TCBS selected medium results showed that Vibrios were controlled within 0~8.6×10³ cfu·mL¹ between April and September,under the measures of water transfer and material control,and peaked in July and August.Furthermore,the black colony found in this experiment was detected by 16S rRNA colony PCR,while the neighbor-joining method in Mega 6 was used to construct phylogenetic tree.In this paper,based on the basic information of this disease and combined with the research progress in recent years,we proposed a series of control measures,which provided a basis for further controlling the occurrence of the disease.