Isolation and identification of pathogen in milky disease of Chinese mitten crab Eriocheir sinensis in Liaoning Province
MA Hongli1, SUN Na2, LU Xiaocen1, LIU Jiannan1, GUO Sicong1, ZHAO Xiaoran1, YE Shigen1*
1.Key Laboratory of Marine Animal Disease Prevention and Control, Dalian Ocean University, Dalian 116023, China; 2.Key Laboratory of Breeding of Eriocheir sinensis, Panjin Ganghe Crab Industry Company Limited, Panjin 124200, China
Abstract: A dominant strain of bacterial pathogen 2EJM001, which grew on YPD and NA and formed round colonies with 1-3 mm white transparent protuberance, was isolated from Chinese mitten crab Eriochiersinensis with “milky disease” weighing 25-35 g and identified as Metschnikowiabicuspidata by morphological, cultivation, physical and chemical properties, drug sensitivity and molecular identification of 18S rDNA. Physiological and biochemical analysis showed that the strain liquefied gelatin, ferment glucose and non-fermentable lactose, raffinose, melibiose, galactose, maltose, starch as well as reduce nitrate to negative. This strain is highly sensitive to ketoconazole, fluconazole and econazole. The 18S rDNA molecular identification and phylogenetic analysis revealed that 2EJM001 was naturally clustered into one branch with M.bicuspidate with the identity of 99.53%. Histopathological examination revealed that the muscle fiber structure was loose, that the striate disappeared, and some areas were dissolved and liquefied. The artificial infection approved that it was pathogenic to healthy Chinese mitten crab showing the same symptoms as natural diseased crab, indicating that M.bicuspidata was the pathogen of “milky disease” of Chinese mitten crab in Liaoning Province.
马红丽, 孙娜, 陆晓岑, 刘建男, 郭思聪, 赵小然, 叶仕根. 辽宁地区中华绒螯蟹“牛奶病”的病原分离与鉴定[J]. 大连海洋大学学报, 2020, 35(5): 714-718.
MA Hongli, SUN Na, LU Xiaocen, LIU Jiannan, GUO Sicong, ZHAO Xiaoran, YE Shigen. Isolation and identification of pathogen in milky disease of Chinese mitten crab Eriocheir sinensis in Liaoning Province. Journal of Dalian Ocean University, 2020, 35(5): 714-718.
2020, Vol. 35 
