渔业科学进展Issue(6)：76-82,7.DOI:10.11758/yykxjz.20140611
氨氮胁迫下凡纳滨对虾对副溶血弧菌的易感性
The Immune Response of Litopenaeus vannamei and Its Susceptibility to Vibrio parahaemolyticus Under Stress Caused by Ammonia Nitrogen at Different Concentrations
摘要
Abstract
Acute Hepatopancreatic Necrosis Syndrome (AHPNS), also know as Early Mortality Syndrome (EMS), was officially reported in China in 2010 and has caused large-scale die-offs of cultivated shrimp in several Asian countries. A research team of the University of Arizona has identified that the pathogen is Vibrio parahaemolyticus which is a strain of a bacterium commonly found in brackish coastal waters around the globe. Because V. parahaemolyticus is a conditioned pathogen, it is very important to study the effects of ammonia nitrogen on the toxicity of this pathogen to Litopenaeus vannamei. To evaluate the effects of total ammonia nitrogen during the outbreak of AHPNS in L. vannamei, we examined the susceptibility to the pathogen, the non-specific immunity and the expression of LvLT mRNA in the hepatopancreas of the shrimp. Shrimp underwent the ammonia stress for 20 days with different ammonia nitrogen concentrations:2.5 mg/L, 5.0 mg/L, 7.5 mg/L, 10.0 mg/L and the control concentration. After the exposure to V. parahaemolyticus, the death rate of shrimp perked in 6–24 h. The accumulative mortality rates of the treated groups were 0, 8%, 12%, 20%and 36%respectively at 120 h. The activities of phenoloxidase (PO) reached the lowest at 12 h in the control, 2.5 and 5.0 mg/L groups, and at 24 h in the 7.5 and 10.0 mg/L groups. The activity of superoxide dismutase (SOD) increased at first and then gradually declined, and lysozyme (LSZ) exhibited the same trend. The expression of LvLT mRNA in the hepatopancreas increased at 6 h in all groups and was significantly higher in the control, 2.5, 5.0 and 7.5 mg/L group than that in the 10.0 mg/L group. The LvLT mRNA expression reached the maximum at 12 h and then declined gradually at 24 h. The results indicated that high ammonia nitrogen could cause depression in the immunity of L. vannamei, and subsequently increase their susceptibility to V. parahaemolyticu and the resultant mortality rate. Therefore it is crucial to regulate the concentration of total ammonia nitrogen in aquatic environment to prevent the breakout of Acute Hepatopancreas Necrosis Syndrome.关键词
凡纳滨对虾/急性肝胰腺坏死综合征/总氨氮/副溶血弧菌Key words
Acute Hepatopancreas Necrosis Syndrome/Litopenaeus vannamei/Total ammonia nitrogen/Vibrio parahaemolyticus分类
农业科技引用本文复制引用
葛红星,李健,陈萍,梁忠秀,任海,李东利..氨氮胁迫下凡纳滨对虾对副溶血弧菌的易感性[J].渔业科学进展,2014,(6):76-82,7.基金项目
国家虾产业技术体系专项(CARS-47)和公益性行业(农业)科研专项(201103034)共同资助。 （CARS-47）
