本年度計畫擬進行現場採樣與分離鑑定菌株,確定相關感染病症與致病原,探討造成魚類體表發生潰瘍之主要病原菌之致病性及致病毒力因子,作為養殖魚類防治體表潰瘍病害之參考.藉由現場採樣了解造成養殖魚類體表發生細菌性潰瘍之主要原因,進行致病菌毒力因子純化,探討主要致病因子對魚隻半致死濃度試驗,及主要毒素中和試驗.進而嘗試研發各種形式試驗性疫苗,探討何者較為可行,期待能有效的消弭廣泛發生於淡海水養殖魚類中的潰瘍病症外,亦能提供養殖業者相關病害防疫參考. The project will investigate the cause of the ulcerative syndrome on fish skin surface and identify the pathogen. The pathogenesis of the disease and related virulence factors will be studies, and will be useful for disease control. The purification and characterization of virulence factors will be conducted. The lethal toxicities of major toxin and its neutralization tests will also be studied. In addition, various types of experimental vaccines will be tried and the better one will then be selected for possible use to reduce the ulcerative syndrome widely distributed in cultured freshwater and marine fishes. The results will be useful for disease control.