a nonluminescent and highly virulent vibrio harveyi strain is associated with “bacterial white tail disease” of litopenaeus vannamei shrimpnonluminescent和高度致命的鳗弧菌菌株与u201c细菌白尾病u201d方面对虾虾.pdfVIP

A Nonluminescent and Highly Virulent Vibrio harveyi Strain Is Associated with ‘‘Bacterial White Tail Disease’’ of Litopenaeus vannamei Shrimp 1 1 2 1 1 1 3 Junfang Zhou *, Wenhong Fang *, Xianle Yang , Shuai Zhou , Linlin Hu , Xincang Li , Xinyong Qi , Hang Su1, Layue Xie1 1 Key Laboratory of Marine and Estuarine Fisheries Resources and Ecology, East China Sea Fisheries Research Institute, Chinese Academy of Fisheries Science, Shanghai, China, 2 Aquatic Pathogen Collection Center of Ministry, Shanghai, China, 3 Shanghai Animal Disease Control Center, Shanghai, China Abstract Recurrent outbreaks of a disease in pond-cultured juvenile and subadult Litopenaeus vannamei shrimp in several districts in China remain an important problem in recent years. The disease was characterized by ‘‘white tail’’ and generally accompanied by mass mortalities. Based on data from the microscopical analyses, PCR detection and 16S rRNA sequencing, a new Vibrio harveyi strain (designated as strain HLB0905) was identified as the etiologic pathogen. The bacterial isolation and challenge tests demonstrated that the HLB0905 strain was nonluminescent but highly virulent. It could cause mass mortality in affected shrimp during a short time period with a low dose of infection. Meanwhile, the histopathological and electron microscopical analysis both showed that the HLB0905 strain could cause severe fiber cell damages and striated muscle necrosis by accumulating in the tail muscle of L. vannamei shrimp, which led the affected shrimp to exhibit white or opaque lesions in the tail. The typical sign was closely similar to that caused by infectious myonecrosis (IMN), white tail disease (WTD) or penaeid white tail disease (PWTD). To differentiat