The effects of stress on the pathogenicity of abalone bacteriophage-like virus to abalone (Haliotis diversicolor)

• Main Authors: Lin, Ya-Pei, 林亞蓓
• Other Authors: Chou, Hsin-Yiu
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/hq7r89

碩士 === 國立臺灣海洋大學 === 水產養殖學系 === 102 === Taiwanese abalone (Haliotis diversicolor) which cultured near the north coast of Taiwan has been found infection of abalone shriveling syndrome-associated virus (AbSV) in 2011. In this study, we undertook experimental infection trails by muscle injecting AbSV filtration into H. diversicolor, following with temporally temperature stress and salinity stress, and observed the change of physical and immune. Abalones with muscle shriveling were collected in 2012 and 2013; PCR detection to confirm these abalones were carrier, later produced the AbSV filtration. Real-time PCR to quantified the virus copies, and health abalones injected with filtration containing 1.75x105, 1.75x104, 1.75x103 virus copies/ml for dose-responses infection trail. The cumulative mortality are 100%, 62.5% and 37.5% respectively. Later we divided abalones into 2 groups, one is challenge with AbSV filtration containing 1.75x104 to 1.75x105 copies/ml, the other one is non-challenge and only inject with L-15 medium. After injection, we stressed them with conditions (20℃, 32℃ and 25‰ for 24 hours, and 25‰ 6 hours a day for 3 days), sampled hemolymph at day 1, 3, 5 , 7, 9 , 14 after stressing, exam and evaluated the total haemocyte count (THC), phenoloxidase (Pro PO) and respiratory burst (RB). The results had showed that significant difference at different day in different salinity stress is more frequently than temperature stress, and non-challenge group is more frequently than challenge groups. Individual difference might cause by stress after challenge with AbSV. Real-time PCR quantified the virus copies in hemolymph and kidney samples collected from day 1, 5, 9, the results indicated that virus copies of hemolymph peaked in day 1 then decreased, and barely detected any change in kidney. Histological analysis including in situ hybridization, had found edema in sinus of gill, also found increase in numbers of mucus cell. And in situ hybridization using ORF 1 (endonuclease) and ORF 2 (terminase) also detected in gill. All the results suggest that AbSV might not pathogenicity to abalones, and could not replicate in host in this study. AbSV might latent in host, and develop into disease when host stressed, even might be lethal to hosts.