Abstract:To define the potential pathogens causing a sick F2 Chinese sturgeon (Acipenser sinensis) in a hatchery of Chinese sturgeon, a bacterial strain EM was isolated from the liver; spleen and ascites of moribund F2 Chinese sturgeon by traditional method of pathogen isolation. The strain EM was identified as Elizabethkingia meningoseptica by means of the 16S rDNA sequence, constructing phylogenetic tree and Biolog Microbial Identification System. The pathogenicity of the strain EM was confirmed by the infection experiment in healthy F2 Dabry’s sturgeon (Acipenser dabryanus). Meanwhile, histopathological analysis was performed in the sick F2 Chinese sturgeon,and the antibiotic susceptibility of the strain EM was carried out to guide the clinically choosing medicine. The results showed that themosiderin deposition, ballooning degeneration and hemolysis severely in liver, spleen and kidney of the sick F2 Chinese sturgeon. The strain EM was cofirmed to be pathogenic to healthy Dabry’s sturgeon by infection experiment, the same bacterium could be recovered from these infected Dabry’s sturgeon.The susceptibility test to antibiotics demonstrated that the strain EM from sick Chinese sturgeon was susceptible to minocycline, clindamycin, clarithromycin,amd midecamycin; medium susceptible to cefotaxime and cefoxitin, but resistant to other 29 kinds of antibiotics, which implied EM strain was resistant to multiple antibiotics.In short, the study firstly shows that Elizabethkingia meningoseptica could be infected Chinese sturgeon, which is also known as a pathogen to Dabry’s sturgeon. Preliminary study on biological characteristics, antibiotic susceptibility of Elizabethkingia meningoseptica, pathological features of diesased F2 Chinese sturgeon, will provide theory basis for disease control and prevention on conservation of Chinese sturgeon.