Bacterial virulence was examined by experimentally infecting healthy shrimp. Healthy freshwater-cultured whiteleg shrimp
(240, averaging 10.1 ± 0.6 g in weight) were obtained from Pinghu Aquaculture Co., Ltd. in Zhejiang, China, and their health
status was assessed through a careful examination of external appearance, gut condition, growth situation, physical behavior
and feeding trends as recommended by the Marine Products Export Development Authority & Network of Aquaculture Centers in Asia–Pacific (2003)