10.6084/m9.figshare.4519058.v1 Hitoshi Nakayama Hitoshi Nakayama Mariko Mori Mariko Mori Teisuke Takita Teisuke Takita Kiyoshi Yasukawa Kiyoshi Yasukawa Keisuke Tanaka Keisuke Tanaka Shunji Hattori Shunji Hattori Hideaki Aikawa Hideaki Aikawa Osamu Hasegawa Osamu Hasegawa Takashi Okamura Takashi Okamura Kentarou Takegami Kentarou Takegami Shogo Motokawa Shogo Motokawa Masakazu Kuwahara Masakazu Kuwahara Kenichi Amano Kenichi Amano Development of immersion vaccine for bacterial cold-water disease in ayu <i>Plecoglossus altivelis</i> Taylor & Francis Group 2017 bacterial cold-water disease Flavobacterium psychrophilum ayu Plecoglossus altivelis collagenase immersion vaccine 2017-01-04 20:03:52 Presentation https://tandf.figshare.com/articles/presentation/Development_of_immersion_vaccine_for_bacterial_cold-water_disease_in_ayu_i_Plecoglossus_altivelis_i_/4519058 <p><i>Flavobacterium psychrophilum</i> (<i>F. psychrophilum</i>) is the causative agent of bacterial cold-water disease (BCWD) that occurs in ayu <i>Plecoglossus altivelis</i>. Formalin-killed cell of <i>F. psychrophilum</i> has long been studied as an immersion vaccine for BCWD. In this study, we explored the possibility of <i>F. psychrophilum</i> collagenase (fpcol) for use as the immersion vaccine. BCWD convalescent ayu sera contained specific IgM antibodies against somatic <i>F. psychrophilum</i> and fpcol, meaning that fpcol is a promising antigen for the vaccine development. The recombinant fpcol was successfully expressed in <i>Escherichia coli</i> and <i>Brevibacillus chosinensis</i> (<i>B. chosinensis</i>). The culture supernatant of the <i>B. chosinensis</i> was used as an immersion vaccine solution. The vaccinated ayu were then challenged by soaking into <i>F. psychrophilum</i> culture. In two experimental groups, the relative percentages of survivals were 63 and 38%, respectively, suggesting that fpcol is promising as the immersion vaccine for ayu-BCWD.</p>