作　　者： ; ; ; ; ; ; ; (邓梦玲）;

机构地区： 四川农业大学动物医学院

出　　处： 《中国兽医学报》 2015年第3期394-400,405,共8页

摘　　要： 南方鲇的溃疡病是近年来发生的一种严重危害南方鲇的病原不清楚的传染病,2013年7月与9月从四川南方鲇养殖区自然感染发病的南方鲇体内分离到2株G-弧形,极生单鞭毛短杆菌(SCCF05与PYD)。其在TSA平板上28℃培养48h,形成表面光滑,边缘整齐,微隆起,乳白色圆形菌落,在TCBS平板上形成绿色菌落。根据分离菌株的形态学和生理生化特性初步判定其为弧菌(Vibrio sp)。16SrDNA与gyrB序列分析表明,2分离株16SrDNA序列(KJ001822、KF907127)与GenBank中V.cholerae 16SrDNA序列同源性最高;而gyrB序列(KC503054、KF998569)与V.mimicus gyrB序列同源性最高。在以分离菌16SrDNA序列及其GenBank中同源性较高的相关序列构建的系统发育树上,2分离菌与V.cholerae和V.mimicus聚为一族;在以gyrB基因序及其GenBank中同源性较高的相关序列构建的系统发育树上,2分离株与V.mimicus聚为一族。在基于弧菌系统发育标志性鉴别基因dnaJ的双重PCR检测中,2分离株基因组DNA中均特异性扩增出约为177bp条带,与预期V.mimicus扩增片段一致,进而鉴定2株分离菌为V.mimicus。2株V.mimicus对链霉素、罗红霉素、丁胺卡那、氟哌酸、氟苯尼考和氧氟沙星等抗菌药物敏感,对头孢曲松与强力霉素耐药。病理学观察发现,V.mimicus感染南方鲇对多组织器官都造成明显的病理损伤,尤其是肌肉、肝、脾、肾的损伤较为严重,表现为明显的出血、变性和坏死以及炎症细胞浸润等。 Ulcerous disease is the most common disease of unknown etiology of Southern catfish(Silurus meridionalis)in recent years.Two Gram-negative,arc-shaped,single polar flagellum brevibacterium(SCCF05and PYD)were isolated from the liver,spleen and kidney of the diseased catfish in Sichuan province during July and September in 2013.Bacterium colonies were smooth and shiny,circular,entire and low convex after incubation on TSA at 28℃for 48 h,while colonies on TCBS were of green color.It was primarily identified to be Vibrio.sp based on thier morphology,physiological and biochemical characteristics.According to the 16 SrRNA sequence of the two strains had a high homology with those of the V.cholerae,while the gyrB sequence was similar to the V.mimicus.A phylogenetic tree was constructed based on the 16 SrDNA sequences of the two isolated strains,together with V.cholerae and V.mimicus formed a tight cluster with high sequence similarities,while the gyrB sequences formed a tight cluster with V.mimicus.And furthermore,in duplex PCR products from the two strains which based on dnaJ sequences,a 177 bp segments were amplified,indicating that the isolated strains were V.mimicus.The two strains were sensitive to streptomycin,roxithromycin,amikacin,norfloxacin,florfenicol and ofloxacin,but resistant to ceftriaxone and doxycycline.Histopathologic observation showed that V.mimicusinfection could lead to serious pathological changes in multiple tissues and organs in Triploph ysa siluroides,which were hemorrhages,degeneration,necrosis and inflammatory cell infiltration,especially in muscle,liver,spleen and kidney.

关 键 词： 南方鲇 拟态弧菌 分离鉴定 病理损伤

领　　域： [农业科学] [农业科学]