Monitor of Koi Herpesvirus Gene and Antibody Response in Infected Koi

• Main Authors: Shang-Chieh Liu, 劉尚杰
• Other Authors: 陳媺玫
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/89010945127535096659

碩士 === 國立臺灣大學 === 獸醫學研究所 === 99 === Abstract Koi herpesvirus (KHV), recently designated Cyprinid herpesvirus 3 (CyHV-3), is the etiological agent of an emerging and mortal disease in common carp (Cyprinius carpio carpio) and koi (Cyprinus carpio koi). KHV was first identified in 1998 as the cause of mass mortality among juvenile and adult koi and among common carp in Israel, and United State. Since its emergence in the late 1900s, this highly contagious pathogen has caused severe financial and economic losses in both koi and common carp culture industries worldwide. In Taiwan, KHV was first reported in December 2002, and occurred continuousely among many areas. According to previous researchers, temperature has effect on KHV disease outbreak, which can occur only at permissive temperature (18-28℃), the highest mortality rates occur 8-12 days postinfection (dpi). Antibody titer began to rise at 10 dpi and plateau at 20-40 dpi. And highly sensitive diagnostic test must be used to identify latent or persistently KHV infected carrier, when fish exposed KHV under non-permissive temperature condition. In this study we tried to imitate the detectable pathogen and antibody produced condition when carp were infected with KHV. 20 Koi carps exposed to the virus at permissive temperature, and then transferred to non-permissive temperature (32℃) in disease acute phase. PCR and Nested-PCR methods was used to identify KHV virus, and neutralization test and ELISA was used to monitor serum antibody. Our results showed that death occurred at 10-20 dpi. Antibody titer began to rise at 10dpi, reach a peak about 20-30 dpi, and maintained at plateau until 70 dpi. When koi became latent infection under non-permissive temperature, KHV can’t identify by PCR method, while Nested-PCR still had positive result.