摘要
为探究中华绒螯蟹Eriocheir sinensis“牛奶病”的病原,从病蟹(体质量25~35 g)体内分离到一株优势菌,记为2EJM001,该菌可生长在YPD和NA培养基上,形成1~3 mm白色不透明隆起的圆形菌落,并对菌株进行了形态观察、生理生化试验、药敏试验及18S rDNA分子鉴定。结果表明:该菌株可以使明胶液化,可发酵葡萄糖,不可发酵乳糖、棉子糖、密二糖、半乳糖、麦芽糖和水解淀粉,硝酸盐还原为阴性;对酮康唑、氟康唑、益康唑等药物高度敏感;18S rDNA分子序列与二尖梅奇酵母Metschnikowia bicuspidata的一致性为99.53%且二者自然聚为一支,亲缘关系较近,将其鉴定为二尖梅奇酵母;组织病理检查发现,病蟹肌纤维结构松散、横纹消失,部分区域溶解液化;人工感染试验发现,该菌株对健康中华绒螯蟹具有致病性,并出现与自然病蟹相同的症状。研究表明,二尖梅奇酵母是辽宁地区中华绒螯蟹“牛奶病”的病原。
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 Eriochier sinensis with“milky disease”weighing 25-35 g and identified as Metschnikowia bicuspidata 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.
作者
马红丽
孙娜
陆晓岑
刘建男
郭思聪
赵小然
叶仕根
MA Hongli;SUN Na;LU Xiaocen;LIU Jiannan;GUO Sicong;ZHAO Xiaoran;YE Shigen(Key Laboratory of Marine Animal Disease Prevention and Control, Dalian Ocean University, Dalian 116023, China;Key Laboratory of Breeding of Eriocheir sinensis, Panjin Ganghe Crab Industry Company Limited, Panjin 124200, China)
出处
《大连海洋大学学报》
CAS
CSCD
北大核心
2020年第5期714-718,共5页
Journal of Dalian Ocean University
基金
辽宁省科技厅重点研发项目(2019JH2/10200006)。
关键词
中华绒鳌蟹
二尖梅奇酵母
牛奶病
Eriochier sinensis
Metschnikowia bicuspidata
milky disease
